JULY 2009

From the Editor by Gordon Banks...... 3 The BIG Picture by Dick Pettit...... 8 Radio Ramblings by Tony Stillman...... 16 The Oily Hand by Brian Winch...... 20 The Webb Scale by Gary Webb...... 33 Two Old Scale Guys by Bill Hurt & Dick Watz....39 Sparky’s Revolt by Tony Coberly...... 45 Bird On A Wire by Terry Dunn...... 50 Fun Aerobatics by Ed Moorman...... 61 Here’s How... by Walt Wilson...... 69

FEATURES Aerial Banner Towing...... 56 Gas Engine Review: RCG F45...... 28 July 2009 3

FROM THE EDITOR by Gordon & Mina Banks

UGLY PICTURES It isn’t hard to imagine the pain and anguish the owner must have felt as he viewed the results of this tragedy, which to him was surely more like a di­ saster (it’s a tragedy when it occurs to someone else, a di­ saster when it occurs to us). Although I don’t see any dam­ age to the transmitter on the upper step of the ladder, the one on the lower step looks bad. But not as bad as that SUV! What happened? I don’t know, I wasn’t there. And the info I got with the photos is sketchy at best. But I’m told that it was the result of leaving unattended a LiPo battery on charge, a charging session that went really, really bad. We may argue tragedy or disaster, but I think we all agree that it was bad. I’ve heard stories of kitchen stoves (been there), TV’s (been there, too), ceiling fans, clothes dryers, space heaters, battery chargers, and other electrical appliances going bad and sometimes causing a fire, but like an attentive babysitter. We ers attempted to charge lithium I’ve never heard a reputable simply trust them to operate chemistry batteries using story of a nickle chemistry bat­ safely. But despite a safety re­ chargers that were not designed tery exploding dangerously, or cord that probably exceeds for that type of cell. The batter­ erupting into flames. Due to 99% when properly charged, ies became so angry at being their overall good safety re­ lithium chemistry batteries improperly handled, they lost cords we tend to accept most have a less than stellar reputa­ their temper and became in- electrical appliances as safe to tion when it comes to home­ home melt-downs and/or fiery use, just as we commonly made fireballs. explosions that sometimes took charge nickle chemistry batter­ This all began, I’ll bet, models, workshops, garages, ies without hovering over them when some uninformed model­ and even entire homes with 4 RC REPORT ONLINE

them to their early, charred Finally, even though it’s not planes our reward for follow­ graves. In most cases the fault widely considered a “rule”, I ing the rules when it come to lies with the modeler(s), not like to use a temperature probe proper battery charging. the charger or the cells them­ that shuts off the charger if the If you’re a parent, you selves. In some instances, how­ battery overheats. probably know how to safely ever, which continue even to­ Now, rules 1-3 are easy to store kitchen knives. If you’re day, cells that were damaged observe, I think. These fall into a gun owner, you probably and should have been dis­ the “set and forget” category, know how to safely store wea­ carded, were put on charge. much like operating one’s re­ pons. If you’re a dog owner, This too can lead to disaster, frigerator. Once we have a you probably know how to pro­ especially if left unattended proper charger and we’ve vide a safe and thus given time for the learned how to set it up for the environment for your dog. If flames to spread unnoticed. battery we intend to charge, we you own a boat, car, motorcy­ The “rules” for charging can just place it and the battery cle, or airplane, you should rechargeable batteries are re­ on a concrete block and we’re know how to safely store mo­ ally pretty simple: done. But that “stay there and torized vehicles. And in most 1. Use only chargers de­ keep an eye on it” rule is often cases we’re talking about stor­ signed for the type and size of hard to do. And it only gets ing them in a manner that pro­ battery being charged. harder after we charge LiPo tects the items, as well as pro­ 2. Make sure the charger’s batteries hundreds of times tecting others (people, pets, adjustments, if any, are prop­ without incident. After all, just etc.) from these items. In short, erly set for the type and size of how long does it take before a responsible owner should the battery being charged. we begin to trust our setups not know how to safely store his or 3. Always have the charger to need constant adult supervi­ her “stuff’. and battery sitting on a fire­ sion? This sounds a lot like Quickly now, how do proof surface. entrusting teenage offspring banks, credit unions, and many 4. Never leave a lithium with the family car, doesn’t it? businesses safely store their battery being charged un­ And just as grandchildren are money while “unattended”? attended. Stay there and keep our reward for not killing and Right, they keep it in a “safe”, an eye on the process until it’s eating our own kids, so is long which is simply short for a completed. lives for our batteries and air­ “safe place”. We do the same July 2009 5

thing with our “stuff’, we put money outside on a concrete on them to retiect your current them in what we consider a driveway. Instead, they keep it favorite brand names. But “safe place”. in a “safe place”. So maybe all America doesn’t like steel So why not do the same we need to do is develop our boxes any more. They rust, when charging batteries “unat­ own “safe place” where we can they get dented, and they cost tended”? It can be done. One charge LiPo batteries without more than a plastic equivalent. easy example is to place the hiring a babysitter. I’m sorry I brought it up. charger and battery outside on In this case, a “safe place” Although steel tool boxes a concrete driveway well away means a fireproof place, and are no longer common in from people, pets, and any ideally one that’s electrically stores, we men have to face the flammable materials. Then if insulated as well. A nice big fact that yard sales are not only the battery goes into “4th of concrete box is what we need, for women. Believe it or not, July” mode, only the battery is and we surely can find them in guys, there’s no law against lost, and the odds are high that many different shapes and men buying otherpeople’s junk the battery was bad anyway. I sizes at the online “Concrete from their front yards. It’s not mean, if we’re using a proper Boxes R Us” store. The only always easy to keep a straight charger, what else would cause trouble with that is, the ship­ face at such outings, and you the battery to act like a Roman ping costs for a concrete box is must never laugh out loud say­ candle? kinda high. The frugal-minded ing something like, “What idiot But okay, we can’t always among us will thus turn to bought this? ” while eyeing one put the charger and battery out­ “rolling our own”. I did. of those pink flamingo yard side on a concrete driveway I made my charging safe ornaments with big white eyes. due to weather, kids, pets, or from an old steel toolbox. I like And if you find yourself staring even the lack of having a con­ steel boxes. They’re tough, at a lacy black 60DD bra, just crete driveway. That may be they can be repainted many pretend you’re having an al­ why banks don’t store their times, and you can put stickers lergy attack or something. This 6 RC REPORT ONLINE is not the proper time to prac­ strong case to get me into a cheap, so I don’t care if they’re tice your stand-up comedy rou­ store that sells tools. pink with green butterflies. Do tine. Trust me (and without Frankly, I already had the batteries really care? asking why, I beg of you!), you something in mind, and I knew Bathroom tiles usually will definitely regret making right where it was. I’d seen it come in boxes containing a lot any comments including the one day in the northwest corner more tiles than I’ll need, but phrase “Guernsey in heat”. of the vast men’s playground some stores, including this one, Actually, I could have so often called “Home Depot”. often have a special little area erected a concrete box if I’d So naturally I began my quest where they sell damaged or wanted to. Buy six of those 2” at the southeast corner. One incomplete packages for about thick, 12” square concrete must check every aisle regu­ half-price. So there I went, and blocks found in the lawn & larly, you know, in case some­ there it was, an open box with garden departments at Home thing new has been added since about half the normal quantity Depot, Lowes, and fasten them the last visit. I think they of some really ugly dark brown together to form a box. If you should send us an email notice tiles. Now, I just can’t help but have room for it, such a box every time they add something wonder who bought the other would cost less than $20 to new. They don’t agree. half, but even moreso whyl Is assemble and it would be great With my shopping cart dark brown a color you really for safety. Of course, you’d growing heavier by the minute, want on your bathroom floor or need an 800 lb. gorilla (or a filling with absolute necessities walls? Let’s move on. football star offspring) to move (work with me here), and my Anyway, for less than ten it, and it would take up a lot of wallet growing proportionately bucks I got enough fireproof space. I have neither, so I said lighter, I finally made my way tiles to line the floor and walls no to concrete. to the bathroom department. I of my toolbox. One bonus here My battery charging safe is once thought it terribly inap­ was that they already look an old steel tool box. Steel, propriate that the many differ­ burned, so one or two mishaps however, conducts electricity, ent toilets were sitting right out would likely go unnoticed by and I think the reasons are ob­ in the open like they are. But I workshop visitors. I think the vious for not wanting an elec­ later learned that they’re for old saying, “Every dark cloud trically conductive charging display purposes only. Who’d has a silver lining” should ap­ safe. And since the charger and have thought that a simple mis­ ply here somehow, but the col­ battery only sit on the bottom understanding could lead to a ors don’t work out. of the box, I could have simply store-wide ban for 30 days? It took me less than an hour added a few bricks or even a 1 ” And there they were, bath­ to glue the tiles in place using a layer of sand. That would room tiles in assorted sizes and tube of Zap-A-Dap-A-Goo. work, and I certainly like the colors. Oh, and prices. Now, Now if I have to leave a LiPo low cost. But the bricks would you may disagree with me battery unattended while charg­ make the safe heavy, and the here, and that’s fine, but I’m ing, I place the charger and sand would likely stick to the not sold on the necessity of battery into the box, route the charger and battery, which is lining the inside of an old steel charger’s power cord through a messy. Cheap is good, but toolbox “tastefully”, which is slot cut for that purpose (and to heavy and/or messy is not what the one and only reason (again, help relieve the pressure of an we want. work with me here) I declined explosion), and close the lid, So I made another visit to Mina’s offer to come with me. locking it in place with the the local home improvement No, I’m thinking more along lid’s built-in clamps. center to see what else I could the lines of low cost. I want Is my Charging Box 100% find. It doesn’t take a really fireproof tiles and I want ‘em safe? Maybe, maybe not. But I July 2009 7

accept the fact that virtually Can’t find a suitable steel nothing is 100% safe, and we box? Other yard sale possibili­ live with all sorts of risk fac­ ties include old fireproof doc­ tors every day, doing our best ument sales, roasting pans and to survive anyway. (Yes, I have pressure cookers with lids, a fire extinguisher in my work­ small outdoor grills with tops, shop.) What’s more, when I and even some small micro­ suggested the alternative of wave ovens (working or not if hiring the very attractive col­ the price is right). Just keep an lege girl down the street to open mind and use your imagi­ babysit my batteries while nation. The first buyer of those charging, even Mina agreed brown tiles sure didn’t. that the box was good enough. -Gordon & Mina Banks Your mileage may vary, so glbanks @ knohgy.net you’ll have to satisfy your own requirements for safety while R/C REPORT MAGAZINE BACK ISSUES charging batteries or storing ...are still available, but only for a limited time. your excess money. But if you For a complete list of what’s available, send a do choose the “outside on the self-addressed #10 envelope with first class concrete driveway” method for postage attached, to... LiPo's or money, please let me Gordon Banks know, and include your name, 116 Longleaf Lane address, and the most common Madison, AL 35758 hours when no one will be at home. 8 RC REPORT ONLINE

THE BIG PICTURE by Dick Pettit

Wow, it’s already the mid­ dle of the new year, and I just celebrated (and survived) an­ other birthday. Where does the time go? It seems like just last week that we were dusting off our models for the new flying season. I’ve already been to the Perry Swap Meet, the Toledo Show, Top Gun 2009, and sev­ eral local flying events, and that’s just the beginning! But there’s still plenty of time left in our flying season to attend many more modeling events in this part of the world. I regret not attending the some rest after spending five hope to be there again next 2009 Joe Nall event this year. hot days down in Lakeland, year, because Top Gun 2010 is It was scheduled so close be­ FL. My charge cards needed a scheduled a few weeks earlier. hind Top Gun, I really needed cool-off period as well. But I

Photo 1: “Dawn Patrol” at Joe Nall 2009.1 sure wish I’d been there to join in the action. July 2009 9

I’ve heard nothing but good reports about the great weather and fine airplanes that flew at Joe Nall this year. Photo 1, for example, shows three giant Pups ready to head out on a Dawn Patrol mission. One be­ longs tomy friend and chief test pilot, Rick Cawley. These are truly outstanding models.

Build-it-yourself fans take note, I just got word that I’ll columnists who focus their I’m often asked, “Which soon receive another BIY kit to attention on scale modeling, to model would you recommend review. This one comes from a include building and detailing, to a first time giant builder? ” company in Canada who makes as seen in “Two Old Scale Frankly, there are so many fine laser-cut kits for quite a few Guys”, by Dick Watz and Bill models worth recommending, beautiful (and huge!) scale mo­ Hurt. Gary Webb covers scale it would be difficult to list dels. Although my project isn’t competition and judging in his them all (especially with my scale, it promises to be just as “Webb Scale” column. Al­ memory). So, what I’m going interesting, with a 106” span, though I’ll often show and dis­ to do is mention some that I and weighing around 20 lbs. It cuss some scale models, my have personally built and flown w i 11 be red with white trim, and primary focus will be on giant over the years, and then let the it was one of the first models models of all kinds. My pri­ modeler make the final deci­ designed expressly to test new mary goal is to help modelers sion based on his personal de­ versions of one of the first mo­ who wish to move up from the sires and requirements. Some dern radio control systems. smaller models to what we re­ people want to jump right into Anybody want to take a guess? fer to as “giants”. This gener­ something scale, while others ally means monoplanes having may want to start out with Now let’s see what else we wing spans of 80" or more, something simpler. have this month. I’ve several biplanes of 60" or more, or any First on my list is the very photos from local pilots, and I model that’s true 1/4 scale or popular SIG Kadet Senior, a took many pictures myself at larger. I may sneak in a model trainer design available as a some local events. I’ll also try now and then that’s a bit small­ 4-ch ARF and a 3-eh BIY kit. to explain the focus of this col­ er, but that won’t occur very Both are light but large models, umn, and add a few sugges­ often. with the ARF having an 80” tions on how to graduate from Where do we begin? Let’s span (see Photo 2) while the smaller planes to giants. Okay, first consider those modelers BIY version has a 78” span then let’s get started. who’ve been flying smaller (see Photo 3). The latter, how­ planes for a while, and have ever, is easily modified to have WHERE AM I GOING? gotten pretty good at it. They the 80" wing required to make Before we get to more pho­ may have built a kit or two, and it a “legal” giant. Since both tos, I want to explain the goals probably a few ARF’s as well. are high-wing trainer designs, I have for this column. RC So we’re not talking about total either can be used as a primary REPORT ONLINE also has newcomers to R/C here. trainer, too. 10 RC REPORT ONLINE

ing so. Either model can be powered by engines as small as .40 2C or .50 4C, but my per­ sonal preference would be a .70 size 4C. Come to think of it, I believe Gordon flics one with a 25 size electric motor. (Editor’s Note: Mine actually uses an E-flite Power 32 mo­ tor, but it has far more than enough goose to it, so it cer­ tainly would fly well with a Power 25.) Even with ai lerons, the Kadet Senior needs only five standard size servos (three will do for the 3-ch version) and an appropriate battery, so the cost of this giant would not be high at all. Next on my list is the Four Star 120, also from SIG (see Photo 4). This one too has an 80” span, but it’s a low wing Photo 4: The aerobatic SIG Four Star 120 is also great on floats. sport design for better aerobat­ ics. It’s a bit heavier than the Kadet Senior, and needs the power of a .120 4C or equiva­ lent for good maneuvers, but it’s a great sport model with which to enter “the land of gi­ ants”. I built and flew a Four Star 120 awhile back, and later added a set of SIG floats. This made it a very enjoyable model with which to enjoy hot after­ noon at a nearby lake. CZ0883N i But as I mentioned earlier, some modelers will want their first giant to be a scale model. In this case they simply must consider one of the many fine Photo 5: Here’s a 1/4 scale Piper J-3 Cub from Hangar 9. J-3 Piper Cub offerings avail­ The 3-ch BIY kit (see Pho an introduction to model build- able today. Hangar 9 offers 1/4 to 3) not only assembles easily, ing. Ailerons can be added if scale versions (see Photo 5) in its construction serves well as desired, and I recommend do­ both an easily assembled ARF, July 2009 11

and a “Plug-N-Play” version where all you have to do is add your receiver! They both have a big 106” span, and both fly very well. Horizon Hobby also offers the very nice ARF Piper Paw­ nee seen in Photo 6. It flies Photo 6: Hangar 9's Giant Piper Pawnee is a good plane with which to great and is easy to transport. start out in Fun Scale And even though I have not yet built or flown the soon-to-be- released Hangar 9 ARF T aylor- craft (see Photo 7), it certainly sounds promising, with a big 80” wing. Either of these two models could be used for sport scale competition, or just for fun weekends at the local field. Great Planes was recently offering a fabric covered 81” Cub. I don’t see it on their cur­ rent list, but you might still find one in a hobby shop or at a swap meet. There are, of course, many other giant Cubs available, so if you find one that peaks your interest, ask around to see if any local modelers know more about the one you like. Great Planes offers numer­ ous introductory level models that would make a good first giant. Their Giant Big Stik, seen in Photo 8, has an 80.5” span and tricycle landing gear, making it an easy transition to large models. But if you want a sleeker and more sporty design, the Giant Super Sportster seen in Photo 9 is a great choice. This one works well with a small gas engine or a suitable glow engine. Photo 8: The Great Planes Giant Big Stik ARF is another nice flying giant. 12 RC REPOR T ONLINE

Oh my. Where do I stop? Even if the list included only the models I’ve owned and enjoyed, it would still be too long for one column! There are just so many good choices! So how about this... if you come across a giant model that at­ tracts you, shoot off an email and I’ll tell you what I know about it, okay? Photo 9: Great Planes Giant Super Sportster ARF, a beautiful low winger Anyway, those I’ve men­ tioned are just a few of the mo­ dels I think would be perfect candidates for newcomers to giant models. Each can be powered by relatively inexpen­ sive engines, none require truly high-dollar servos, and they’re all big enough to qualify as giants and too see well in the air. And keep in mind that not only do giants look better in the sky, they fly better as well! Remember too that some of Photo 10: The Great Planes RV-4 ARF is a small but true 1/4 scale giant. the ARF kits are also available as BIY kits, so ask around if you prefer to build your own. I encourage modelers to build a BIY kit of some kind in the near future. We must preserve the art and skills of model building.

YES IT’S A LADY Jacqui Lewis, of Raleigh, NC, a member of RDRC and wife of local pilot, Larry Lewis, is seen in Photo 11 with Photo 11: Jacqui Lewis, of Raleigh, NC with her Gee Bee Model Y her Pacific Aeromodels 82” The Great Planes 1/4 scale and great flying characteristics span Gee Bee Model Y. Pow­ RV-4 seen in Photo 10 has make it an ideal candidate for ered by an SPE-43 gas engine only a 70” span, but it still qua- sport flying or as an intro to swinging a Vess 2IB prop, this lifies as a giant since it’s true fun scale competition. beautiful model is guided by a 1/4 scale. Its low wing design Then there’s the... Spektrum DX-7 radio. Jacqui July 2009 13 has been flying for about a year radios, such is not always the quencies! Something has to and a half now, and flew this case. Although very rare, and give, and gravity is going to year at the big, Joe Nall Fly In, certainly less frequent than the win! (Editor’s Note: Keep in something she’s wanted to do common and well known prob­ mind, guys, that when you hear for a long time. lems inherent with the limited about events at which over 100 number of 72 MHz frequen­ models were in the air at the RADIOS FOR 2010 cies, there have been some same time, not all o f them have I often receive letters ask­ documented cases of possibly to be using 2.4 GHz radios. ing about the status and reli­ overloading the 2.4 GHz band, There are still 50 useable fre­ ability of today’s radio sys­ when an unusually large num­ quencies on the 72 MHz band, tems. I hope by now that you ber of pilots have their trans­ plus those on HAM and the 27 have read the article in the final mitters turned on. This includes MHz frequencies.) print issue of “R/C REPORT” those who are flying, others What can we do? Person­ (March 2009), by Cal Orr, the who are testing some aspect of ally, I think the really large former radio columnist for their models, and others who events should employ a limited “RC Modeler” magazine. If have their transmitters turned number of 2.4 GHz “pilot not, try to find and read this on for any number of reasons. pins”, in addition to the normal very enlightening article, One such incident is said to “frequency pins” for the 27,50, wherein Cal carried out several have occurred at the 2009 Joe and 72 MHz bands. All trans­ exhaustive tests on numerous Nall event, when several 2.4 mitters should be impounded, 2.4 GHz radio systems. That GHz transmitters “locked out”, and only those pilots with a pin article made quite an impres­ resulting in an ugly outcome. are allowed to have and operate sion on me, even though I had How could this happen? Since their transmitters. There would already converted to 2.4 GHz there were no frequency pins be only one “frequency pin” gear. issued to pilots using 2.4 GHz for each of the 27, 50, and 72 I realize that many of you radios, there was no limit en­ MHz band frequencies, of are still using your tried and forced on how many 2.4 GHz course, and a limited number true 72 MHz radios, and with radios could be operated at the of pins for the 2.4 GHz band. good reason. It can be very same time. The flight line may How many, you ask? That expensive to replace a large have been full, with another would be something for the collection of transmitters and dozen or so waiting to fly, an­ radio experts to decide, but 20 receivers. Plus, with so many other 20 or more down at the to 25 seems reasonable to me, modelers jumping onto the 2.4 3D area, still more at the lake to allow for unforseen circum­ GHz band, the old 72 MHz flying float planes, and who stances (kids playing with 2.4 frequencies are becoming less knows how many more flying GHz R/C toys, for example). and less crowded, making helicopters. At such a large and By the way, I’ve heard that those older frequencies even highly attended event, it’s re­ 2.4 GHz radios will be re­ more attractive than before! ally not hard to imagine 80 or quired at the Top Gun and Joe And make no mistakes about it, more 2.4 GHz transmitters be­ Nall events in 2010, with no there are no plans to do away ing turned on at the same time! exceptions. I think I understand with the 72 MHz frequencies And I don’t care how bullet­ why they came to this decision, any time in the near future. proof these radios are, a hun­ but I still have mixed feelings Despite the highly touted dred 2.4 GHz transmitters sim­ about it. promise of “interference free” ply cannot operate safely on flying with the new 2.4 GHz the 80 available 2.4 GHz fre­ 14 RC REPORT ONLINE

A CROWD PLEASER Photo 13 shows Kelly San­ derson, of Beulaville, NC, with his new Top Flite Corsair. Kelly built the plane from a kit, and used Warbird Colors paints over the fiberglass finish. The plane weighs 30 lbs. powered by a ZDZ-80 gas engine turn­ ing a 26x10 prop. Robart main gear and a modified tail wheel assembly support the plane on the ground. Kelly uses JR radio Photo 13: Kelly Sanderson, of Beulaville, NC, and his Top Flite Corsair gear in all his models. Local flying sites hosting while, if you’re planning to smaller events need to keep the attend a major event in 2010, A SMALL GIANT EVENT facts in mind, but will likely be sure to check on the radio One of the local clubs in my need less stringent rules since requirements. If the Top Gun area held an IMAA sanctioned many already require pilot pins and Joe Nall coordinators have event a while back, and for a for all transmitters, regardless reached this decision, you can noontime demonstration they of their frequency. As always, bet your last glow plug that held a different kind of “giant however, this should be left up others will follow. Personally, event” (see Photo 14). The to the club officers and contest I’d start planning right now to models were small, but the directors. upgrade at least some of our number was large! Nineteen of So, now that I’ve opened better models to the modern the extremely popular (and this can of R/C worm, let us radio systems, at least those practically identical!) Park know what you think. Mean­ still using vacuum tubes! Zone T-28 RTF electric models

Photo 14: These aren’t large planes, but there’s a large number of them, a fleet of super popular Park Zone T-28’s ready to mass launch. July 2009 15

local event. Jeff, from Roanoke Rapids, NC, a former scale columnist for “R/C REPORT” magazine, was even kind enough to take two raffle win­ ners for a ride in his beautiful Stearman.

Well, we’ve come to the end of another column, and I’m running low on both photos Photo 15: Note the right aileron after a minor mid-air collision. and ideas for future issues. all took off at the same time calls, but everyone had a great Please share some photos of from the same runway! Once time and they plan to fly even your favorite giants, and let us they were all airborne, it was more at one time in the near know what you’d like to read every plane for itself, but future. about here in the coming amazingly, only one plane was months. Until then, see y’all at damaged by a mid-air collision, HERE’S A REAL BIG ONE the field. -Dick Pettit and that one remained in the air Photo 16 shows Jeff Foley 5704 Dedmon Ct. until the very end (see Photo flying low and slow over the Durham, NC 27713 15). There were a lot of close flying field in his Stearman at a [email protected]

Photo 16: Here’s former RCR columnist, and many times scale champion, Jeff Foley in his full scale Stearman. 16 RC REPOR T ONLINE

RADIO RAMBLINGS by Tony Stillman

It is definitely summer now! Temps arc often reaching triple-digits here in the south, which can mean lots of great flying time, but be sure to drink plenty of fluids while you're outside. And don't forget the sun screen either!

PCM vs. PPM (again!) I recently received the fol­ lowing email from a reader: “I just read your column about PCM vs PPM in the May issue. I think you left out a very important point. The PPM sig­ for a word in the noise, it can ply not true. ” nal, when it gets into the noise recognize the word at a level Richard H. Kelly level, gets dithered by noise far below where dithering spikes. The servo then begins takes place in a PPM system. It Thanks, Richard. You are to get antsy. Some like this as can read (further) down in the correct, of course, and you’ve they can tell when they are get­ noise. offered a good explanation of ting close to the end. “Backwhen interpulse cod­ what’s going on. “PCM, on the other hand, ing was introduced to radars, it The bottom line here is that is transmitted via a digital perm itted a 3db increase in the PCM receivers will work well ‘word'. In the transmitter, each sensitivity of the receiver. A in noisier situations than FM pulse is sent to an a/d con­ 3bd increase in the receiver (PPM). The PCM decoder adds verter that converts its width to sensitivity is the same as dou­ a level of noise blocking that a digital word that’s transmit­ bling the transmitter power. makes this happen. This is why ted to the receiver. The re­ “Several years ago I had a I prefer PCM receivers in my ceiver looks at the word and severe problem with ignition models when I’m not using 2.4 decides if it’s authentic, and noise from a ZDZ80. I could GHz system. converts it back to a pulse not get control even l O' from width if it passes the tests. If (the model) with the engine MORE ON BATTERIES the receiver decides the word running. I replaced the PPM It seem that wc can never has been corrupted, it sends receiver with a PCM receiver. escape battery discussions here the last good word to the servo. Then 1 could get twice as far in Radio Ramblings. I’ve heard If the receiver has received from the model with the engine a lot of complaints about bat­ severed corrupted words, then running. I then flew the plane teries lately, so I thought I'd it goes into fail safe. You could several times. There are those share with you what I’ve heard, have some servos getting good who say the sensitivity of the seen, and learned over just the words and others not for a pe­ two receivers are the same, past few months. riod o f time. since they both use the same Here at the Radio South When the PCM receiver looks F M transmission. That is sim ­ service center I’ve been using July 2009 17 REGAIN CONTROL Losing control can be a nightmare. The wrong response to a given command can take its toll, on your model, your nerves, and your wallet! At Radio South we know how you feel about your hobby. W e too are avid RC enthusiasts with nearly half a century of combined experience in modeling and radio repair. So, avoid inflated repair costs and undue service time — call Radio South for fast, economical, in-house radio service, that you can depend on. “At Radio South, customer satisfaction isn't just a motto. Iťs our way of life." Let us put you back in control. NOW WITH 2 locations to serve you better! 139 Altama Connector, #322 6847 N. 9th Ave., Suite A #320 Brunswick, GA 31525 Pensacola, FL 32504 (Tony Stillman, 800-962-7802) (Ben Pham, 850-426-0820) Questions? Call us Toll Free at 800- 962-7802 Visit our website for more information at www.radiosouthrc.com

Sanyo cells exclusively for or five times and your battery these changes, the charge char­ nearly 20 years, and they have should be seasoned and ready acteristics of the cells changed. always worked very well. Sure, for normal use. But note and Normally, NiCd and NiMH you find an occasional problem record the final discharge ca­ cells behave similarly in cell, but they’ve been few and pacity for future reference. charge, except that NiCd’s far between. Here’s where the problems “peak” when fully charged, This has not been the case started. I received some batter­ while NiMH’s simply “flatten over the last three or four ies that customers complained out”. I’m referring to the volt­ months, however. I don’t know about. When I ran them age level when viewed on a what’s happened, but Sanyo through some break-in cycles, graphic display. I’m sure most seems to have changed some­ they still didn’t show a suffi­ of you are familiar with “peak thing in the way they manufac­ cient capacity. I saw some charging” NiCd cells, and this ture their NiCd and NiMH 1100 mah NiCd and 2300 mah is what I’m referring to. cells. NiMH batteries that were cy­ A NiCd cell increases in The first indication came cling at less than 50% of their voltage steadily while being from customers who com­ rated capacity! This is not charged. When fully charged, plained about poor discharge good! the cell’s energy “spills over”, and cycle times with brand new After discussing the issue actually causing a slight drop cells. Most of the time I find with my battery supplier, I in voltage. This creates the that they are not charged suffi­ learned that they too were hav­ “peak” we can see on a voltage ciently, or that the customer is ing trouble getting more than graph. This peak is used by trying to fast-charge them be­ 90% of the rated capacity when most of today’s NiCd chargers fore “seasoning” the cells. cycled. I couldn’t even get that to determine when the cell(s) With new NiCd and NiMH much, so I asked lot of ques­ are fully charged. cells, it’s important to “season” tions, and here’s what I found NiMH cells are similar, but or “break-in” the cells so they out. the voltage doesn’t peak, it just can obtain their full capacity At some point (and fairly quits rising and flattens out. potential. To do this, simply recently, it seems), Sanyo (and When charging NiMH cells, charge the battery at C/10 (1/10 probably other battery manu­ it’s important to select the the rated capacity marked on facturers as well) made some proper charge program so that the cells) for 24 hours. Then, changes in the design and the charger will detect this discharge the battery using a make-up of their cells. These change and cut off properly. cycler, or by just operating the changes were supposed to in­ (Editor's Note: I can’t speak of unit until the battery runs crease the cells’ capacity, but it other smart-chargers, but the down. Repeat this process four had an unexpected effect. After Hobbico Accu-Cycle Elite al- 18 RC REPOR T ONLINE lows the user to select the sen­ sitivity of peak detection. Us­ ing 8 mv forNiCd’s, and 3 mv for NiMH’s works nicely, as the charger the “sees” the flat­ tening voltage as a sort of peak when charging NiMH’s.) So, what’s going on? It seems that the changes in the cells actually made the NiMH cells “step” instead of flatten. The graph would look like a set of stair steps, increasing in voltage, flattening out for a short time, and then going up again. The step fools many chargers into thinking that the cell is fully charged, so it auto­ matically switches over to the lower trickle charge rate. I personally have not been able to verify this “stepping”, but I’m told that this is what’s happening. In order to ensure a full charge, we need to make sure our charger is overlooking these steps. I too use a Hobbico Accu-Cycle Elite, where we can go into the cycle charge setup and modify the cut-off (or a little higher) for 40 hours can set like this, use it to sea­ settings so that it will not be so or so! In fact, they need to get son your new batteries. sensitive. This way, it will ig­ a little warm when charging! After following this proce­ nore the steps and only cut off For some reason, these new dure for a while, I was able to when the pack is fully charged. cells want to be pushed much get my cells up to 90% of their I don’t have any specific num­ harder when seasoning. The rated capacity. I also found out bers to give you right now, but problem with this is that it’s that Sanyo now sets its dis­ I cut mine back about 60%, and becoming increasingly difficult charge voltage at 0.9 volts per now it seems to be working to find fixed-rate, constant cur­ cell, so in order to achieve that fine. We can also modify the rent chargers that don’t cut off “90%” figure (or better), you’ll peak charge settings for automatically! You used to be need to set your cycler to cut NiCd’s. And once I made the able to get the ACE Dual Me­ off at 0.9 volts per cell instead changes, my chargers ran lon­ tered Vari-Charger DM VC) of 1.1 volts. ger and I got better capacity that would do this job per­ Now sit tight, because I’m from all of my test cells. fectly. It had dual outputs to not at all sure that this is the I also learned something handle batteries of 1-10 cells, final word on this situation. I else. It’s very important that and would charge up to 500ma. hope to learn more about this you charge these cells at C/10 If you have something that you subject, and I will keep you July 2009 19

Kraft and Ace transmitter cases. Working with the folks at XPS, we have come up with a module version that works great in old, Kraft transmitters. I’ve installed them in 1971 sin­ gle sticks, all the way up to the later Kraft systems. I even put one in an EK Logitrol case from the late 60's! The nice thing about 2.4 GHz is that there is no FCC certification required to make the change, unlike the narrow banding that was done years ago. The FCC allows this retro­ fit without any certification, as the RF units are already certi­ fied, and the FCC allows that kind of change in this fre­ quency band. This has really opened up some options, especially to the single-stick fliers out there. Now you can find just about any single stick transmitter and convert it to 2.4 GHz. The cost is reasonable and it makes a very solid system. I’ve had sev­ eral customers bring out old equipment to refurbish and fly, as a set with an old model and engine that they flew 25-30 years ago. It’s really cool to see this stuff being used again, and brought out to the flying field so the new folks can see what an old Pro-Line or Orbit set actually looked like, and then see it fly! Awesome! -Tony Stillman posted on whatever I learn. If UPDATING OLD 139 Altima Connector, you have any knowledge or TRANSMITTERS Box 322 input on this subject, please let This has become a hot topic Brunswick, GA 31525 me know by phone or email. at Radio South lately! I’ve tony @radio southrc .com been kept very busy installing 2.4 GHz radio systems into old 20 RC REPORT ONL!NE

The Oily Hand by Brian Winch

ANOTHER OPENING, ANOTHER SHOW Well, thanks to Tony Cobcrly we have been resur­ rected from the pizza boxes in Gordon’s office, to show up in full color with all the whistles and bells online. I note that old Grumpy Bum is still around, though (Hello sweetie, how's ycr belly where the pig bit you?), and the rest of the flight crew arc carrying out their du­ ties very nicely too. So without further ado (just what is “ado”, anyway?), let’s get a bit more times five or six... but never business drive made it hard for into the action. I’ll be submit­ more than seven!). Shirley an­ him to quit anything. He was ting my versions of engine re­ swered it and delivered the never a loser, but common views as you have already seen message. “Kanga (the name sense must prevail at some in the first online issues. I’m had been changed to protect point, and he was looking at his interested to hear if you like the innocent) wants to speak past record without anticipating this, in-depth style of review or with the master. ” He’s a good a rosy future. I first met Kanga not. friend, a modeler, and a very when he came to me with an knowledgeable person in his engine problem. Over a period WHAT'S UP, SPARKIE? profession. He's been involved of time we became close I like to carry out a few in modeling for quite a few friends, and I started pushing yard chores in the morning, years. Due to the time restraints him to take a more active role feeding my fish their morning of his business, he's had other in his modeling, with less reli­ treats, and giving nuts, fruit, modelers build and set up his ance on others to build and set and bread to the birds (I have a models with many failures. It's up his models. It was a hard bit of a zoo.) Dog biscuits arc a sad fact of life in many cases, road, however, as he lacked handed out to my three dogs, that a person building for confidence in his own building. while Shirley tends to the five somebody else might not take Now keep in mind that he’s a cats. Then I relax and have the necessary care, which re­ very intelligent guy. Anything breakfast while reading the sults in models that fly poorly less would not have rendered daily news (but mostly the and often crash quickly. So, so much success in business. comics). Sure as eggs, four Kanga has crashed many mod­ But this is common with many mornings out of seven the els... many, many models. In modelers who come into the phone will ring just as I get recent years he’s been nearing hobby late in life. Many are comfortably seated with eating the point of giving up and intelligent, clever, and articu­ tool in hand. This morning was looking for another hobby. But late, but the often lack a bit of one of the four (okay, some­ his Oriental background and confidence due to the fear of July 2009 21

(ground) wire, but more on that later. Then wave the sensor over the magnet. Wait. A word of caution is due here. Don’t let the sensor sit on the magnet without mov­ ing or it may be damaged in­ side. The sensor is inserted in the mounting bracket, and then a small wedge is pushed in. If you put the sensor in the brack­ et the wrong way around, it is almost a ‘seek and destroy’ job to get it out again. Generally, one side of the sensor tip is Photo 7: Orientation of the sensor is important, as it must be in flat, and the other side is slight­ accordance with the polarity of the magnet exciter in the propeller hub. ly wedge-shaped so you can failure (spelled, crashing!). So tions for buying a replacement visually check. Once you’ve what if the model crashes? It unit, and when it arrived I told established the correct orienta­ happens to all modelers some him that he would have to test tion, insert the sensor into the time or another. After all, mod­ and install it, but I would guide bracket before you do the final els last only until they are him over the phone. Well, he job of jamming it in with the crashed or sold (and then had a tizzic fit at that, coming wedge (see Photo 7). crashed). Anyway, slowly but up with loads of excuses. But Well, after the mandatory surely, I got Kanga into doing I’m a tough old bugger, and moaning and grumbling, he more and more for himself, and never backed down. I wanted carried out the test, and to his he was enjoying the new ad­ him to do the job, no matter great joy (and satisfaction) he venture in every step. Eventu­ how much he complained and saw a spark at the spark plug. ally he completely set up an blubbered. This way he’d gain This was his first success with ARF scale model almost en­ a better understanding of the electronic gizmos. tirely on his own (with just a ignition, as well as having the Then a pall fell over the few phone calls), and it flew satisfaction of having done the conversation. “I ’ve read the well! Needless to say, he was job himself instructions and I see that I re-captured. His first task was to orient have to time the engine at 30°. The next step was a bit of the sensor. The sensor is pole What does that mean? How do engine work. He rang to say sensitive as far as the magnetic I do that? I f it’s wrong, will the that his petrol engine wouldn’t exciter (a small magnet) in the sky fall on me? ” I explained start. After a few questions I propeller hub. The magnet will that this job had already been determined the problem and he be either north or south pole done for him, since his engine learned a new lesson... you upwards, and the sensor is po­ had always been a spark igni­ cannot test a CDI unit (Capaci­ larized to react one side to the tion type, and nothing changes tor Discharge Ignition) without north pole and the other side to from engine to engine once the a ground connection to the the south pole. It’s a simple magnet is set correctly in the spark plug, or for that matter, matter to set up the ignition drive hub. Even so, I gave him having a plug connected. He unit, making sure that the plug a brief run down on how en­ had thus cooked the jellybeans lead is earthed (grounded). I gine timing is checked and set in the CDI. I gave him instruc­ usually add another earth up for the needed value. 22 RC REPORT ONLINE

were the same brand as an en­ gine I’d tested not so long ago. I spent the best part of a day fabricating a safe mounting system for the 85cc brute. An engine that size, swinging a 27" log, is a deadly machine quite capable of removing a hand and a head, and maybe even a hardwood head! Mount­ ing it safely requires consider­ able thought. One safety factor is vibration. A single cylinder engine unavoidably vibrates when running, and the amount Photo 5: Using a Dial Test Indicator to check the piston position for of vibration is usually propor­ timing purposes. tionate to the engine’s dis­ placement. As such, an 85cc engine shakes like a bowl full of Jell-0 in the hands of a tipsy waiter. After setting up a suitable mounting arrangement, I then spent way too many hours flicking, checking, cursing, flicking, and more flicking. And all I got was one stiff shoulder and one very short engine run. F irst I completely disassem­ bled the Tillotson carburetor (no big problem), and then test­ ed the spark, trying several dif­ ferent plugs and a range of plug gaps. All wiring was ‘‘Bloody hell, ” he swore, “I rotten beast! (Brian, not the checked, as was the battery for could never do that!” poor ‘roo ’.)) the CDI. I found no problem, “All in time, ” I said (see but there was still no joy with Photos 5 & 6). SPARK BUT NO RUN the engine. Frustrated, I de­ I left him at that point, but I had two engines on my cided to set it aside for the lime asked him to report back when bench from two different mod­ being. My right arm was al­ he’d flown his model. In the elers, but both had the same most useless by then anyway. meantime, I encountered a problem, hard to start and very Although I do have an electric problem that had me scratch ing unreliable with consistent short starter suitable for that size my hardwood head and kicking run times. One was a big 85cc engine, I did not have a spinner a stray kangaroo that got in my brute of a thing, while the other to fit the engine, and you need way. (Editor's Note: Stinkin’ was a milder 58cc, and both a spinner for this starter. July 2009 23

on to see the plug sparking in a small mirror. And if you really knew what you were doing, you’d raise the air pressure up to simulate the cylinder pres­ sure of the engine, around 130 psi. If the plug was faulty it would cither cease sparking or the spark would be dancing all over the place. In simple terms, the increased pressure at the firing end causes a form of electrical resistance that may prevent proper operation if the plug is bad or worn out. Could Photo 1: How it was in the beginning. This good old Brown Junior is still this be the problem with the going strong, and starts every time with no more than three flicks. two recalcitrant engines on my The next day I set up the (which are quite small). You bench? No. I knew this wasn’t 58cc engine, which was much may have a real job on your the case as I had already tested easier since it fit well on my hands trying to get it out, too. the spark plug in my own en­ testbench. I stripped the carbu­ Please, add the fuel line filter gine. retor down and found a reason­ by all means, but leave the in­ What about the CDI unit? able amount of junk in the fil­ ternal filter in place. Could it be too weak to over­ ter, so I hoped that was its only Now, just as with the 85cc come the higher spark resis­ problem. While I had the carb engine, this one would fire and tance when the cylinder pres­ in pieces, I fitted anew carb kit burble a bit, but would not run sure built up? The symptoms because the later versions of more than a second or two. All make sense. The engine would Walbro carbs are much better checks proved fruitless, so in sometimes run for a few sec­ than the old ones, particularly desperation I peeked inside the onds, just enough time for the flap valve plates. engine, although I’ll admit good working pressure to de­ We now interrupt our regu­ right now that I had no idea velop, and then the sparking larly scheduled program for a what the bloody hell I was stopped. word about filters. I’ve read in looking for! Eery test I could So I hooked up another CDI a model magazine where it was run yielded satisfactory results, unit, and... on the very first advised to remove the filter except for one thing... the en­ flick it started and ran like a mesh from the carb, and use a gine still wouldn’t run. clock! (Editor's Note: And one fuel filter in the fuel line. No, Then, like a bolt from the revolution per hour is good?) not me! For sure I’ll add a fuel blue, a spark hit me. In days After six more first-flick starts, line filter. This is always a gone by, you could trot down I let it run flat out for 15 min­ good practice. But don’t re­ to your friendly service station utes, and all went perfectly. move the carb’s internal filter. to clean and test the old used Yep, the CDI had a pain in its If it’s not in place when a for­ spark plugs from your car or jellybeans (electronics). I then eign body (hair, lint, etc.) bike. One at a time, the plugs fitted both engines with new somehow passes through the were screwed into the machine, CDI units, and had two very line filter (and it does happen), grit-blasted clean, air blown to happy customers, plus one that crud goes directly into the remove any remaining grit, and pleased Oily Hand and one stiff fuel passages and jet orifices then you turned the high power shoulder. 24 RC REPORT ONLINE

from his description I was not convinced that it was enough to cause a disruption to the fuel supply. But then I remembered that he had been overseas for a while on a business trip. “How long has it been since the en­ gine was last run?” He said it was last run during the latter days of summer, during a very warm spell. It was now winter and raining. “When you reas­ semble the carb, turn the main je t needle out 1/4 turn. The carb is set too lean. ” I soon heard the engine singing a fine Gemini Twin? song (well, up to high ‘C’, any­ This was a difficult prob­ “Bless you, Grasshopper’’, I way). End of problem. lem to isolate. I currently have said. “How can I help you? ” Well, maybe not. The very no way of testing a spark plug His gas engine was giving him next morning he called me under pressure, but I’m going trouble again. It would start from the flying field (he likes to build a test unit for future and idle well, but it cut out as to fly before going to work) to work... and my own satisfac­ soon as he advanced the throt­ say I was wrong! tion. tle past half. With his previ­ Why me? What had I done I know the second engine ously gained knowledge, he to deserve this? (Editor's Note: had been involved in several had checked the entire ignition You want that list in alphabeti­ disasters (i.e., sudden, un­ system and all seemed well in cal or chronological order?) planned arrivals), so that could that department. My suggestion The engine was still running have upset a jelly bean or two was that the filter in the carb well, but it had no torque. “The inside the CDI, or maybe an might be partially blocked. model took a long time to take internal connection. The 85cc “Oh no, ” he moaned. “You ’re off. Then it didn’t fly well and engine, however, had not been not going to make me pull the would not climb. I couldn’t crashed (at least not to my carburetor apart are you? ” even get it to level out for a knowledge), but it vibrated so I love this part. “I sure am, good landing, so it nosed down much, maybe it shook the day­ so scoop up a good-fitting on the final approach. ” lights out of the CDI. screwdriver. ” I ignored the “What changes did you Anyway, it was a good renewed moaning and sobbing, make since yesterday? ”, I ask­ learning experience, and some­ and then told him how to re­ ed. thing we can note on the wall move the two cover plates off “Nothing, ” he protested. for the future in case you have the Walbro carb so he could “All I did was change props, a spark engine problem. gain a bit of insight as to what but I fitted the same size, a was inside. I also assured him 20x8. ” BACK TO KANGA: that nothing was going to fly “What prop did you take This week Kanga called out and bite him. After a time off?”, I asked again. Shirley answered the he found the filter and carefully “A Bolly wood. ” phone, and he again requested slid it out with a pin. It did “ What did you put on ? ” an audience with the master. have a bit of rubbish in it, but “A Master Airscrew plastic July 2009 25

Photo 3: A giant scale Cessna powered by a very reliable lOOcc gas twin

18x8 ”, he replied. popped up again! The owner an error from a well known ‘‘The plastic prop is a lot called to say he’d received it, manufacturer? This just proves heavier then the wood prop, but after flicking the prop for again that you cannot accept all right? ”, I asked. half a day (ring up one more things on face value. It’s now a ‘‘Oh yeah, a lot heavier. ”, stiff shoulder), he decided to lesson learned and stored in my he answered. try the old CDI again. I can’t hard drive (the official “TOH ‘‘And you balanced that even begin to understand why Memory”). model at 25%? ”, asked I. he went back to the old unit, I’d seen a video of this en­ ‘‘Yes, right on 25% ever but he found that not only was gine in a model being flown, since the test flights. ” the original CDI faulty (as I and I knew it was fitted with a “Kanga?”, said I. had found), but the engine was prop just over the top of the “yes? ”, said he. timed incorrectly. suggested range, but I assumed “Your model is now nose Now, this is a brand new that the automatic timing of the heavy with the heavier prop. ” engine from a well known CDI was taking care of it. The I don’t think our prim and company, but the ignition set­ main reason I didn’t catch the proper prissy editor will allow up is done by the sel 1 i ng dealer. problem was due to there being me to tell you what Kanga said Why? I dunno. two magnets in the hub. One is as he hung up. The magnet in the hub was for a fail safe system that cuts set 30° after top dead center the ignition off if there’s no STOP THE PRESSES! instead of before, which is con­ engine action after a brief idle This will rot your socks! siderably retarded! I know, I period. I should have checked That (Australian expletive de­ should have picked up on that which magnet was used to ex­ leted) 85cc engine problem myself. But who’d expect such cite the ignition... but I didn’t. 26 RC REPOR T ONLINE

Photo 4: Here s an economy biplane. You save on horizontal stabilizers! Actually it’s a scale model of a French Pou du Ceil (Flying Flea), a popular home-built tailless biplane design of the 1930's. A BAD CALL with the idea of using honey, the workshop. I just closed the When T ony Coberly invited since it has a high viscosity like door and threw the bolt before me to write for the online ver­ heavy oil. Well, as you can sitting back to ponder the sion of RC REPORT, he prob­ imagine, honey in the winter is Doppler effect of ol’ bird brain ably didn’t know that my pea­ not the easiest liquid to pour being chased around the work­ brained former assistant uses into a 1/4" glow plug hole. His shop by a cloud of angry bees. the same email address as I, so bright idea was to heat the (I still wonder why they were now he’s back! I caught him in honey to lower its viscosity, angry.) From the far end of the my workshop going through pour it in while it was hot, and shop I could hear “Brrrzzz my notes on checking compres­ then let it cool before measur­ Wow!”. Then from closer to sion ratios of engines where ing. Sure it’s a stupid idea, but the door I’d hear “Brrrzzz you use oil to measure the that’s what he was on about. Wow Slap.” This went on for swept volume and the combus­ Now it’s a plain fact that hon­ quite a while, but I eventually tion chamber for the correct ey, when heated, gives off a had to leave and re-open my answer. I noted that thick oil very strong aroma, and that underground workshop. was recommended in days past, aroma is a magic drawing card as it had a higher viscosity for... guess who... bees! But he APRILWUN - DOT than thin oil, and the old pe­ heated the honey anyway, and ROT - DOT - CON dantic motor engineers had to the aroma wafted up and out Just as before, anything do every job “by the book”. I the roof vent. Soon every bee discussed here is not to be at­ also noted that the thick oils within a five mile radius tempted by any sane (or other­ generally used then are no lon­ homed in on the smell and flew wise) person, as it’s nothing ger available, but there are sub­ in through the flue. It was actu­ more than a figment of my stitutes that can be used. ally pretty interesting to see imagination, much like our Well, ol’ “bugs for brains” several thousand bees hum­ editor. To even attempt carry­ pondered this and came up ming and buzzing as they filled ing out any of these expert men- July 2009 27

ACCESSORIES NEW COCKPIT KITS SEE TEMP PRODUCTS! INST.GUAGES B-25 KMP / H 9 / Ziroli CANOPY RAILS G U N SIG H T S B F -109 KMP / Platt RIVET DETAIL KITS MACHINE GUNS F4U Corsair DS / Ziroli / KMP / CA JB ACCESS PANELS B O M B D R O PS P-47 H9 / KMP / Ziroli COCKPIT KITS G U N K ITS P-51 H9/TF/KM P/Zir/CA B A L SA W O O D W IN G T U B ES S pitfire KMP / Platt DYNAMIC BALSA S tuka KM P/Ziroli www.dbalsa.com T -28 Cox/Pica/ Platt 815-856-2272 or 856-2271 F W 190 KMP / Platt / Val fax 815-856-2270 COMING SOON! em ail: dvnamidtiöblmtc.net D o n S P -47 WWI Cockpits AMR Waco lal projects could cause harm to to stop the flow of deadly, oily same time as the second tank is your great - great grandparents, substances that come from the full. This is commensurate with your children’s children’s chil­ burning of tobacco, and other­ the size of the engine and the dren, the local postal delivery wise wind up in your body. muffler, and once its clogged person, and your pet wombat. Then fit a standard size nipple with oil, the muffler pressure If you even have a thought of in the bottom rear section of will blow the filter out and the trying any of these ideas, dis­ the engine muffler. Next you’ll oil will stop flowing into the cuss the matter with a medical need an extra fuel tank in your tank. At this time you will see professional before signing model. Now, to set up this re­ smoke from the muffler. This yourself into an institution for covery system, ram a filter into signals that you need a break metal treatment, (or is that ‘men­ the exhaust outlet of the muf­ from flying, so land the model, tal”? Whatever.) fler, and connect the muffler switch the oil line to the now This month’s great idea is a nipple with fuel tubing to the empty tank, fill it with your oil­ real dollar saver, and an envi­ extra fuel tank you installed in less fuel, and the model is once ronmentally friendly idea to put the model. According to your again ready to fly, using the an end to the chore of cleaning fuel mix preference, say 18% tank of recycled oil. your model after flight. Before oil, you fill the spare tank with Just think... you may never we move on, however, it’s vi­ 82% of its capacity using your have to buy oil for your fuel tally important that you under­ methanol/nitro mix. This tank ever again. Yes, it’s another stand this: lubricating oil docs has only one outlet, and that’s brilliant insight from the never- not wear out, it just becomes to your main tank. In operation, ending supply of absolute spif- polluted. When you consider the filter will stop the oil from fy ideas from Winch - The how much oil is left on the flowing out the muffler, so it Well Oiled Wiz. model after a flight, you can will drip to the bottom and be -Brian Winch easily see how much is wasted blown into the extra fuel tank. 33 Hillview Parade in discarded paper towels. In­ Due to engine vibration and Lurnea, NSW stead, why not use it again? model movement, the oil will Australia 2170 From your local cigar store mix with the fuel and you will [email protected] buy a packet of cigarette filters eventually have a full tank of like those used by smokers mixed fuel! After careful cal­ who roll their own cigarettes, culation, I found that the filter or use them in cigarette hold­ in the muffler will eventually ers. These filters are designed load up with oil at close to the 28 RC REPORT ONLINE RC ENGINE REPORT TEST ONLINE REPORT

E n g in e...... RCGF 45 center prop bolt and washer, three small prop Manufacturer .... RCGF Model and Engine bolts, and four standoffs with mounting Mfg. Co., China hardware. Importer/Distributor .... RC Aero Products Bore X Stroke ...... 1.69x1.22" (43x31mm) 2045 Niagara Falls Blvd., #9 Actual Displacement ...... 45cc (2.74 c.i.) Niagara Falls, NY 14304 Recommended RPM Range .... 1500-7600 (905)688-3947 Advertised Power...... 4.3 BHP [email protected] Schnuerle Ported ...... Yes www.zrcgf.com ABC D esign...... No List P rice ...... $269.99 Ball Bearings...... Two on crankshaft, Warranty ...... One year plus roller bearings on the connecting rod Muffler Included . . . Yes Engine-only W eight...... 53 oz. Glow Plug Included ...... Yes Muffler Weight...... 3.8 oz. Tools ...... Spark Plug Socket and Ignition Unit Weight ...... 3.8 oz. two Allen wrenches Total W eight...... 60.6 oz. (ignition Accessories ...... RCEXL Ignition unit, switch and battery not included) July 2009 29

Recommended Props . . . 20x8, 20x10, 22x8 Overall Length ...... 7.88" Overall Height ...... 6.5" Overall Width at M ount...... 3.88" Overall Width at Carb...... 2" Firewall to Prop, m inim um ...... 5.5" Crank Center to Outermost Point . . 2.25" (muffler not included) Mounting Plate W idth ...... 3.63" Mounting Hole Centers, Side to Side 3.38" Mounting Hole Centers, Top to Bot . 2.13" Propshaft Diameter...... 10mm Propshaft Length ...... 40mm bolt Muffler L ength...... 4.38" Muffler Width ...... 1.88" COMPARED TO OTHER 45cc ENGINES Side Projection...... 1.88" PROP 20x10 APC 22x8 APC Fuel U sed...... 87 octane gasoline, RCGF 45 7320 6900 mixed 50:1 with Amzoil Sabre Brand A 6330 6700 Sparkplug Used ...... As supplied Brand B not tested 6650 Brand C 7240 6700 NOTE: All Test Props are APC composites unless otherwise noted. CHEERS - Light weight; excellent power; easy to start; relatively quiet; distributor is very responsive to customer concerns. Minimum Reliable Idle P ropeller...... RPM JEERS - Several dimensions in the manual do 1 8 x 1 0 ...... 1620 not match the engine; choke plate hole prevents 20x8 ...... 1560 proper priming; throttle and choke arms are too 20x10 ...... 1470 short for accurate operation; awkward carburetor 22x8 ...... 1260 orientation (but see text for a fix); smooth, non­ griping drive washer. Maximum Measured Noise: dB(A) Propeller @10’ @25’ Seen in ad for the engine: 1 8 x 1 0 ...... 1 0 4 ...... 95 “ZRCGF is the USA/Canadian Distributor 2 0 x 8 ...... 1 0 1 ...... 93 for the RCGF Model & Engine Mfg. Co. The 20x10 ...... 103 94 company has established its model aircraft 2 2 x 8 ...... 1 0 1 ...... 92 engine division and quickly positioned itself as a high-value manufacturer of gas engines specif­ Maximum Measured RPM ically designed for giant model aircraft. Propeller RPM (‘Our manufacturing facility has its own 18x10 ...... 8340 research and development department, and this 20x8 ...... 8010 contributes to the extraordinary quality and 20x10 ...... 7320 price points in our product line. Our engines are 22x8 ...... 6900 continually tested across the world, by pilots in all disciplines, under all sorts of conditions and circumstances. This allows us to respond to 30 RC REPORT ONLINE

the needs o f our modeling com­ munity quickly and efficiently. “At ZRCGF our engine quality, power, warranty, ser­ vice, and ease o f use can be yours at a reasonable price. Giant scale flying has never been more economically avail­ able. ”

The first time I saw the ad­ vertising above, I decided right away to take a closer look at some of their products. I need­ ed an engine for an upcoming project, and ZRCGF had sev­ eral sizes available that might work in the new plane. I con­ tacted the distributor, and re­ ceived a very nice reply stating wrenches, and the instructions ments taken care of, I bolted that they would be very inter­ manual. The prop washer, in the RCGF 45 to my test stand ested in allowing us to review addition to it’s main hole, also and prepared to run it for the any of their engines, and espe­ has three holes for the smaller first time. According to the cially if that engine would be prop bolts, but I’d rather not instructions, “Ground running used in a model review as well. drill out my test props for just should be done with a slightly At first I was interested in their one engine. The 10mm center smaller prop, and with the 50cc twin, until I learned that bolt will work fine if you add a cowl off to promote good cool­ the spark plug boots would piece of double-sided sandpa­ ing. It is not recommended that protrude through the sides of per behind the prop to keep it you run the engine on a test the cowl, so I chose the 45cc from slipping against the stand, as they do not allow vi­ single instead. Shortly after smooth drive washer. bration energy to be properly giving them my shipping ad­ The four standoffs are de­ dissipated. Plus, it is not need­ dress and plastic-money ac­ signed for engine mounting ed. Your engine is ready to count number, the RCGF 45 arrangements where the carbu­ g o .” arrived at my shop. retor will be inside an engine Sorry, but I always test en­ I immediately removed ev­ mounting box, leaving the cyl­ gines on my test stand. It is not erything from the box, and inder head and muffler out in a rock-solid bench that does spread out all the pieces on my the open. I’ll make up a ply­ not shake and twist as the en­ workbench. This included a wood sub-firewall to be used gine is running, however. It can side-mounted muffler with gas­ with the factory standoffs to and will move side to side a ket and moumting bolts, a large have the carburetor clear the little, providing some “vibra­ (10mm) prop bolt with washer, mounting plate on my engine tion absorption” much like an three auxiliary prop bolts, a set test fixture. If that works out airplane would. of four standoffs with mount­ well, I’ll later use the same Since I was using the sup­ ing hardware, an RCEXL igni­ arrangement to hang the engine plied side-mount muffler that tion unit, a spark plug, a spark on the airplane. doesn’t interfere with the carbu­ plug wrench, two small Allen With the mounting arrange­ retor’s fuel mixture needles, I July 2009 31

connected the throttle linkage plained what I’d discovered. the throttle and choke arms are to the carb, bolted the engine to He asked only a few questions too short to provide adequate the stand, and connected the before promptly agreeing to resolution in operation. I re­ ignition system and fuel tank replace the engine. I agreed to placed the throttle arm with a line. The RCEXL ignition box return the one I had, so it could reworked nose wheel steering can use a 4- or 5-cell battery, be inspected to determine what arm, and added a brass exten­ so I chose a fresh 5-cell 1650 caused the problem. I was sion to the choke arm. Longer mah NiMH. pleased that they wanted their arms allow finer adjustment of I was just about to start the engines to be perfect when de- both functions. I also removed engine for the first time when I livered, and were willing to the end of the spring from the noticed something peculiar make things right if necessary. throttle arm, but left the spring about the way the prop hub was The replacement engine arrived in place to help keep the throt­ moving as the prop was ro­ in three days, and when I tle plate from vibrating and tated. It appeared to be wob­ checked its crankshaft, it was wearing the carburetor bore. bling quite a bit. I removed the within 0.002" of being perfect. Another problem I’ve found prop and spark plug, and used I later learned that the first en­ with most Walbro carbs is that a dial indicator to find that the gine’s crankshaft was not bent, the choke plate has a hole in it crankshaft was bent, causing but had been assembled im­ to help prevent flooding when the prop hub to wobble! I have properly aligned at the factory. used in industrial applications. no idea how this happened, Henry, at RCGF, contacted the With model airplanes, how­ since the engine was brand factory to ensure that such does ever, this hole doesn’t allow new, and the shipping box not happen again. much fuel to be sucked into the showed no damage at all. Like nearly all Walbro car­ carburetor. I like to seal this I called ZRCGF and ex­ buretors on engines this size, hole with a small dab of solder, 32 RC REPORT ONLINE after which the carburetor can were all completed with no the next shipment of engines. I be primed with just a few flips further problems at all. drilled and tapped my block of the prop. During the test runs I began rather than wait for a new one, With the engine securely to notice that the RPM figures and the carburetor operates just fastened to my test stand, I seemed very good for an en­ fine now. turned on the ignition, fully gine this size, so I checked the closed the choke, and set the figures I’d recorded for three W ell, what more can I say? throttle to about half open. Af­ other 45cc gas engines I’d run. The RCGF 45 engine has prov­ ter three flips, the engine burp­ Using the same props I reserve en to be a lightweight but pow­ ed to indicate that it was ready for engine reviews, the RCGF erful engine that produces to start. After opening the 45 did indeed prove more pow­ more RPM than three other choke and setting the throttle to erful than the other three en­ engines this size that I’ve test­ a high idle, the engine started gines. Plus, none of the other ed. Other than a few minor in only three more flips. It ran three started as easily, which glitches that can be solved by quite well too, albeit a bit on was equally impressive. The the user, and one big problem the rich side. I let it run at sound levels I recorded were that was solved quickly and about 4000 RPM for almost 30 all well in line with the other question-free by the distributor, minutes, and then let it sit and three engines, and should pass the RCGF 45 is a really nice cool off. Then I refilled the most of the suggested maxi­ engine for the modest price .I’ll tank and began the test runs. mum noise levels for both 10' be bolting mine into the nose From that point on, the engine and 25'. It doesn’t meet the of a new plane soon... well, as never needed more than two AMA’s “90 db at 9”’ recom­ soon as I get it built! flips to restart, which I found mendation, but I’ve never seen -Dick Pettit impressive. The carburetor a stock-muffler gas engine that [email protected] needles required minor adjust­ would! ments for each different size I also made a few inquiries HOSPITAL CHART prop, but the engine always about the position of the carbu­ BLOOPERS started easily. retor on the back of the engine. 1. The patient refused autopsy. At first there was some I was concerned that if a Pitts- 2. The patient has no previous slight but noticeable misfiring -style muffler were used, the history of suicides. at full throttle high RPM, but it needle valves would point di­ 3. Patient has left white blood ran just fine at 3/4 throttle. I rectly toward the muffler. I cells at another hospital. tried adjusting the fuel mix­ found that the carburetor can 4. Patient has no fever today, tures, but this messed up the be rotated 180° after you install but her husband says she was otherwise fine throttle transi­ a longer piece of tubing be­ very hot in bed last night. tion. I called and talked with a tween the crankcase fitting and 5. Patient has chest pain if she few modelers who already have the vacuum inlet on the carb. lies on left side for over a year. some experience with RCGF But this alignment puts the 6. On the second day the knee engines, several of whom rec­ throttle and choke connections was better, and on the third day ommended opening the spark right next to the muffler. The it disappeared. plug gap to 0.032". When I carburetor mounting block, 7. The patient is tearful and tried that, the engine immedi­ however, can be re-drilled and crying constantly. She also ap­ ately ran much smoother at tapped to rotate the carb 90, pears to be depressed. high speed, and it allowed a 180, or 270°, giving a lot more 8. Discharge status: Alive but better low speed adjustment for flexibility to engine mounting. without permission. a smoother and more reliable I also heard that the factory is 9. Patient was examined in ER, idle. After that, my test runs drilling the blocks this way on x-rated, and discharged. July 2009 33

The Webb Scale by Gary Webb

By the time you read this, Top Gun will have once again come and gone. Congratula­ tions to all the contestants, be­ cause I consider every one of them winners due to the fact that this is an invitational event... you have to be a win­ ner just to get an invitation! Out “hats o ff’ to David Hayes and his Rockwell Thrush for not only taking first place in the Masters class, but also for earning the highest combined score and being pro­ claimed “Mr. Top Gun”! From a judge’s point of view, the crop dusting routine David per­ Gun” honor. flying talent, their F-16 was formed was simply spectacu­ In Team scale, Graeme presented in a very convincing, lar! Mears and David Shulman realistic, and unbeatable man­ Greg Hahn again won the formed this year’s dream team. ner. It’s an extremely rare oc­ Expert class with his B-25D, Graeme gave David a perfect currence for anyone to earn a and gave David Hayes a close 100 point static score to begin perfect 100 points in static, and run for the coveted “Mr. Top with, and with David's great I believe this was the first time this has happened at a Top Gun event. In other words, in the static judges’ eyes, Graeme’s F-16 was a perfect rendition of the full scale aircraft, with no flaws! And no one, in over 20 years of Top Gun competition, has ever accomplished this feat before. Incredible! Graeme is one of the most dedicated builders out there. I’ll be doing an interview with him in an upcoming issue, along with some other top competitors from around the world. John Boyko, who won the amateur side of the Pro-Am David Shulman(Orange shirt) and his brother Jason, ready the F-16 for another mission. class last year, was moved up 34 RC REPOR T ONLINE

North of Lakeland, FL, right after Top Gun. I dropped the wife off on the way down, so she can spend time with them as well. On the way to their house, you pass through a little town named Wildwood. (Yes, I started singing that song too.) As I drove down the main street I saw a hobby store remi­ niscent of days gone by, and just had to stop. It was closed at the time, but was scheduled to open in a few hours. Since Wildwood is only about ten miles from where my sister lives, I decided to come back A rare British Vulcan bomber later to check it out. to the pro side this year. Some try telling John that you can't What a walk into the past! people said “Welcome to the do something during rehabilita­ Noell's Hobbies is packed with majors, John. ” last year. Wel­ tion! I hope to interview John all kinds of model aircraft, come indeed, because John soon too. He motivates us all to many hanging from the ceiling, stepped up to the plate, met the strive for the best we can be. and stocked to the rafters with challenge head on, and won the John’s model, by the way, is an kits, engines, radios, and all Pro side this year! He is such awesome Pitts Sl-S. sorts of modeling supplies. an inspiration to everyone Mike Selby, a retired U S AF There are R/C cars and boats as around him. John, you see, has Colonel who now lives in Thai­ well. I needed some Zap Hinge Cerebral Palsy, and at times land, always brings a new and Glue for the KMP B-25, and has trouble getting around. He fascinating model to Top Gun. thought they might have it. has to sit on a stool while he This year was no exception, Sure enough, they had a com­ flies. He, of course, insists that with his super-fine F-l 1 IE. plete selection, and I bought all he has no disability, he just I normally spend some time the Zap Hinge Glue they had, walks differently, yet he’s also with my sister and her husband which is hard to find in Ohio a physical therapist! So don’t who live in “The Villages” just hobby stores. Jack Noell has owned and operated his store for over 28 years. He started out part time, but after retiring from a local steel company, he now devotes most of his time to the store... when he’s not out flying (test­ ing his products, I’m sure!). He has two loyal and very knowl­ edgeable employees, so if you’re ever in the area, stop in and tell them Gary sent you! July 2009 35

Williams, at 92 the oldest liv­ ing WWII fighter and bomber pilot of the Tuskegee Airmen, was the parade’s Grand Mar­ shall. He was also given the task of tossing the wreath from the memorial bridge at the half­ way point of the parade. I’m told that Mr. Williams was the first black man ever to be be­ stowed this honor. There were literally tens of thousands of people lining the parade route. The airmen were given a standing ovation the entire route. Even the truck driver who pulled the large float said he was moved to tears at the outpouring of affec­ Memorial Day has come ond largest Memorial Day pa­ tion. To see the many veterans and gone, but I hope you did rade in the U.S.! along the parade route stand something to honor our mili­ My FiberClassics Mustang and salute them was very, very tary veterans. I was again in­ and the Kondor Model Prod­ moving. It was also wonderful volved with the Tuskegee Air­ ucts B-25 were both used. The to hear them tell their stories men, beginning with a parade Mustang was in the parade on after dinner. in Springfield, OH. I didn’t the float, and was seen again in know it until after the fact, but the large hall for an indoor dis­ I received an email from Springfield's parade is the sec­ play during the dinner. C.I. Rick concerning his repair to a Byron's Original Staggerwing Beech (I’ve built five of these models in the past.) “Hi Gary. I t’s been a long time, but I'm back with more questions if you don't mind. I don't recall what happened at the DOGS show nearly six years ago, but to make a long story short, I finally got the Staggerwing flying last week­ end. We made two great flights on Sunday, and one more on Monday, proving the plane to be a good flyer. The final flight on Monday, however, was made during some strong cross-wind gusts which caused squadron, flying the B-25's. me to snap it and crash on 36 RC REPOR T ONLINE

straightening a foam wing (about 6” o f one tip in crushed) andfilling the dings and dents? Would 3 oz. glass cloth be too heavy (it's what I have on hand)? During this rebuild, I want to add tail gear doors. Have you ever done this or seen it done? Have you any details or advice to share? Do you know anyone who pro­ duces windshields for this mo­ del? How about replacement decals? Thanks in advance for any help you can give me. Rick Vera-Burgos Mr. C.I. Williams is the man with the white ball cap and B-25 lapel pin who was Grand Marshall of the parade. Sorry to hear about the takeoff. I now need to repair 25 year old model, I ’m going to crash, Rick. First, the cowl and the cowl, both wings, and re­ completely redo the exterior. windshields should be avail­ place the firewall. The foam parts are covered able through Iron-Bay Models. Would a thicker firewall be with what looks like Econocote, If he has time, John should be advisable, or should I stick but I want to glass and paint it. able to pull a new windshield with the 1/8" stock thickness? Do you have any advice about and make a new cowl for you. Since the paint is peeling and removing the coveringfrom the At present they cannot make cracking all over this possibly foam? Also, any advice on the foam parts due to their steam boiler being down. The wing can be repaired, however, with blue or pink foam. Glue it in place with 30-min epoxy. Fill any dents and dings with lightweight Dap spackling, found at most hardware stores. If the wing is broken in two, I’d use 1/8" to 3/16" carbon fiber rods, connecting both haves at least at the leading and trailing edges to add support to the joint. To remove the Econocote, I’d try to coax it off with low heat. Too much heat will cause the foram to expand, giving the texture of a football. Don Cummings was a B-25 pilot during WW11. His crew was As for the firewall, I’d stick noted to be able to drop a dumb bomb in a pickle barrel from ten thousand feet. with the 1/8" seven-ply ply- July 2009 37

1:1 to apply it. Then lightly sand with 320 paper, and do a second coat with 2:1 mixture of epoxy to alcohol. All of the Staggerwings I built had tail wheel doors. I used the spring wire method to open and close them with the wheel pulling the doors closed as it touches the spring wire. I hope this helps, Rick. Please keep me posted on your progress.

I'm now finishing up some repairs on my C Mustang, which I plan to take to the Mac Part of the huge crowd lining the streets on both sides to honor our Hodges war bird event, along Vets and present service members.. with my trusty old L-4.1 want­ wood, because it also acts as a I’d use 1/2 to 3/4 oz. cloth to ed to take my new KMP Sky- flex-plate and vibration damp­ glass a surface that’s sheeted raider, but there's a size limit, ener. I have never had one fail. with balsa or 1/64" ply. If you with giant scale models only. I A thicker firewall will just add use this light a cloth over foam, may take it to fly in the evening weight. though, you may puncture the hours, though, after the event As far as glass cloth goes, cloth while handling the parts officially ends at 5:00 p.m. use 1.5 oz. cloth. This provides after painting. Ouch! So I rec­ enough strength without a lot ommend using 1.5 oz. cloth. I'd Get started on a scale model of weight gain from trying to also use Zap Finishing Resin, of your choice. Send us an fill a heavier cloth. Normally thinned with denatured alcohol email about your choice, and the fun you have hunting down the documentation to make your model realistic. That wraps it up for me this month. Stay tuned for some upcoming interviews with sev­ eral of the world's leading scale modelers. Fair winds and blue skies... -Gary Webb [email protected]

Mr. C.I. Williams was a B-25 pilot during WWII. 2009 War Bird Visit RocketCityRC.com Event for information Door Prizes to be awarded Food and Refreshments available Rocket City Radio Landing Fee $25 Controllers SORRY. NO VENDERS ALLOWED Huntsville, AL CD- Alan Berard 256-417-5499

University Dr.

Bob Wallace Dr.

Drake Avenue

Johnson Road p· July 17th and 18, 2009 Airport GPS Info: Friday at 1200, and Saturday 0800 till 1700 Wilbourn Field 34 41.192 N Spectators Welcomed John £ RCRC Flying Site H unt 86 35.725 W Pilots Meeting at 0800 Saturday 2 Jaycees Building P ark Overnight Camping Available, no hook-ups

Come by the Home field or RCReport Online for our War bird event in July!

Keep an eye at RocketcityRC.Com all year to see what events are coming up! We would love to see you there! July 2009 39

Two Old Scale Guys by Dick Watz & Bill Hurt

Ebesfeld-Fairchild Sopwith Camel

D W : Hi Bill. It sounds like ing in the seat of a WACO 10 the boot cowl the whole time Top Gun 2009 was another was the high point of my youn­ we were flying. great experience. I’d like to ger days, and maybe the most hear your comments about it fun you could have with your D W : Bill is a full scale pi­ when you have time. clothes on. Right, Bill? lot with a love and respect for I’m sure that most of you aviation in general, he has a know that Bill is an Outline B H : We both had the won­ real soft spot in his heart for Judge at Top Gun, and the derful experience of getting to the venerable WACO. Will founder of the WACO Brother­ fly in full scale Waco aircraft Rogers once said, “I don’t hood. The latter is a group of when we were kids. My grand­ know if I ’d want to be a mem­ aviation lovers who believe father owned a YMF and a ber of any club that would have when the last WACO lands, the Standard biplane. Some of my me as a member. ” But I agree sky will return to being just earliest recollections around with Bill. Lordy those empty air. I’m proud to be a airplanes has to do with flying WACO’s are cool. I love the member of this organization, in one of granddad’s planes, WACO Brotherhood as much too. Of the many great planes and evidently he also owned a as Stickman. Oh, sorry Bill. I of the Golden Age (1920- Monocoupe because I remem­ meant Stick builder. (Did I say 1940), none has the romance ber flying in one of them, and that out loud?) Bill is six foot and beauty of the WACO. Rid­ watching the rivets spinning in three inches of twisted steel 40 RC REPORT ONLINE

Fuori-DiGorgio AC-47. and sex appeal. Oh well, one get to enjoy wringing my more. I’ve lost 120 lbs. With a out of two isn’t bad. I must planes out with both feet firmly name like “Dick”, I’m sure you have been thinking about his planted on terra-firma. I really can come back with something. stature when I said Stickman. do miss flying the little bipe Brian might say, “No worries I’m going to give you two lines though, and what do you mean mate. I know your patch, and I to get even, Bill. Go! “one out of two”? Oh yeah, get to the colonies from time to I’ve shrunk a little so I’m only time. ” Speaking of Brian, he BH: Well, Bill is no longer six feet two and a half inches and his wife are two of the a full scale pilot, since I lost tall now. (Snicker.) sweetest people. Mrs. Winch my ability to pass the physical knitted me a plane when I was after my cardiovascular acci­ DW: I ’m sorry you can’t recuperating, and Brian called dent (i.e., heart attack). Now I call me the Big Dicker any me on the phone. What nice

Fuori-DiGorgio AC-47 July 2009 41

Mears-Shulman F-16. people! So I did some research One email I received asked My new project for Wen­ and learned that the plane she if I planned on doing another dell could be a 100" (approxi­ knitted is under consideration plane for Wendell Hostetler. mate) Luscombe Silvair. I have as Australia’s new, front line Yes, I do. As some of you may the plans now, and have al­ fighter to replace the J-3 Cub. know, Eric ran into some trou­ ready started cutting. It will be Is that true, Brian? ble last year and couldn’t finish all metal, not a rag wing. Own­ In the months to come we’ll the Navion in time for Toledo ers of the Luscombe say the follow the construction of my this past spring, but I cut a kit metal wing flies better, so F4F, Eric’s F7F, and Bill’s for Eric and the Navion will be maybe the model will too. The 27% YMF5. There will be lots coming soon. Wendell has the plans will show the rib layout to talk about, but keep sending plans ready now along with the so you could build either ver­ email and pictures. Remember, Cessna 195 I did two years sion. this is your column too. ago.

Newman-Ziroli Feisler Storch. 42 RC REPORT ONLINE

Simpson-Jones N2S-3 Stearman.tif

If I modeled for a hundred never seen a full scale airplane about all the available paints, more years, I’ll never under­ that was covered with iron-on and after all these years I still stand why people will spend plastic film. Since I’m a bona- come back to epoxy. If I was hundreds of hours building and fide scale modeler, it would not painting control line or free finishing a sport model that be fair for me to comment fur­ flight, I’m sure I’d still use looks like the box it came in. ther on these miniature air­ dope, which I did for years, What are your thoughts on that, planes. mainly because it’s lighter. The Bill? I say if you’re going to In the columns to come we classics and heavy metal I put out the effort, then make it will bring you building infor­ build now aren’t bothered by mean something. It’s been said, mation, surface detail tips, fin­ an extra ounce or two of paint. “God does not deduct from, ishing information, contest This is a subject on which your time on earth the hours knowledge, and anything else we could write an entire col­ you spend modeling”, so I you’d like to know. We don’t umn, right Bill? think it should be spent on have all the answers, but we’ll scale modeling. try our very best to make your BH: I think that would scale building experience a make a wonderful topic for a BH: Well Dick, I don’t happy and rewarding one. future column. Personally, I’ve know all that much about sport A question often asked is used the old Pettit Hobby Poxy, models or even sport scale air­ what paint to use? I like to and liked it very much, and I planes since they all pretty spray epoxy. That’s a good understand that the Klass Kote much look like flying crosses question, isn’t it, Bill? I’m sure finishes are much like that old to me. Some of them even look you have some thoughts on product. I use a lot of dope like a flying bread sack. I’ve that. Actually, I’ve tried just (Wait... that didn’t come out July 2009 43 right!) and automotive base hope to understand the south­ ing five days you’ll likely ever coat/clear coat more than any ern accent a little better, so spend. It doesn’t matter if other finish. when I fly at an air show down you’re a competitor, an offi­ south, and they say, “You all cial, or just an observer. The DW: I use mostly silk or come to the flight line now”, intensity has to be experienced other shrink-type fabric cover­ I’ll know a little better what to be believed. ings instead of plastic. As a top they’re talking about. In Michi­ This year, I met some new scale modeler once told me at gan they just say, “Get your six people who were attending as Toledo, when they start putting to the flight line right now!’’, contestants for the first time. plastic shrink coverings on not “You all come”. Talk about having “big eyes”! classics and war birds, then I’ll Sorry Bill, you may have to The sheer magnitude of the start using it on my models. straighten this out for me. I’m event is simply mind boggling. I’m not sure, but I think Bill a northerner and don’t even There were a lot of the regulars would have something to say live in southern Michigan! in attendance, of course, and about this as well. I’m going to leave you with some who were missed in their Bill now. I’m sure he has plen­ absence. Some new planes BH: I normally don’t use ty to say about Top Gun and made the cut, and there were any iron-on materials. I use the my poor southern accent. some who have either timed time-tested Koverall fabric Take it away, my brother. out or this was the last year that’s applied with nitrate dope. And I’ll see “you all’’ next their model could compete. I’m Most don’t realize it, but ni­ month. really going to miss Mike trate dope is actually nothing Barbee’s Big Yellow YMF. more than clear nitrocellulose BH: As usual, Dick, you He’s working to finish his lacquer. It can also be thinned Yankees have it screwed up! It Texan II for next year, and I’m with lacquer thinner rather than is not now, has never been, sure that it’s a superb airplane, having to deal with dope thin­ and probably never will be, but (sigh) it ain’t a Waco. ner. “You all.” It’s “Y’all”! And I Mitch Epstein had his new guess this is as a good a time as 33% YMF there this year, and DW: I can’t remember, but any to straighten this out. it’s a beauty too (I posted a it seems like it was something “Y’all” can be used in the sin­ photo of his plane last month). about putting a bread wrapper gular, plural, or even the There are always some very on a scale model plane. Eric pulperfect subjunctive. If I say unusual entries, and this year does a superb job with plastics “Y ’all come”, that could mean was no exception. There was a on his 3-D planes, but those you, or it could mean you, you, Formation Stearman, a TU-95 guys are looking to save every you, you, and you. But if I say Bear, an Aardvark F-l 11, and ounce they can. I’m sure you “All Y’all”, then it means for of course the faultless F-l6 of know by now, I’ve never met a everyone as a group to come on Graeme Mears was back. Da­ plane I didn’t like. I think down. It’s actually very simple. vid Hayes had his Thrush fly­ Golden Age is the most varied ing just like the real McCoy and interesting, but warbirds Top Gun 2009: Wow, what again this year. That thing even are fun to build and fly, too. an event that was! It’s actually has scale grit on the engine! In this column, we will more than an event it’s a hap­ Dick Pettit included a lot of eventually cover some of all pening! And it takes on a life photos in his report last month, different types, to include the of its own being the most de­ but I have lots of pictures of different building and flying manding five days that you’ll great models on the judging aspects. Be sure and let us likely ever spend, and at the table. I’ll be posting them from know what interests you. I same time it’s the most reward­ time to time. These are views 44 RC REPORT ONLINE

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Symbol of Excellence’ just as I see them, but it may be years with a civilian agricul­ whole new level. It’s almost a new way for you to see these tural airplane. It’s a tail dragger like a five day party for scale models. and it has no machine guns or model enthusiast. I mentioned that Graeme bombs. What it docs have is I’ll be posting more photos Mcars’ F-16 was faultless, and “believability” (and in spades!) in the coming months, and indeed it appears to be. It is and a pilot who knows how to hopefully I’ll be able to pro­ possible to score a perfect 100 fly it well within the scale en­ vide a little more in the way of in static judging, but it’s never velope. This model is not “too a personal touch regarding been done at Top Gun until this slick” and not “too pretty”. It these fine models. year. Oh, several have come looks real! It looks used and -Dick Watz close, but Graeme finally nail­ worn, just like 99% of the ag 8400 Swan Creek Rd. ed it. You really need to spend planes you’ll sec across the Saginaw, MI 48609 a lot of time looking over this country. It flies like its on rails, [email protected] model. It looks like he picked it though, and David makes it off the vine before it grew to look sooooo easy! And you -Bill Hurt full size! Everyone who comes know what else? He didn’t 1212 Oak Drive in contact with Graeme should “ver detail” it, either. Nothing, Leesburg, FL 34748 congratulate him. not one single thing jumps out vt Ulici m h u rt@ c o m cast.net I’ve heard for years that jets at you as being overdone. It’s and warbirds have an advan­ an excellent and well executed tage at scale contests, but Top scale model, and he flies it to Gun proves that this ain’t so. perfection. David Hayes has taken home Top Gun takes the scale the top marbles for the past two aeromodeling experience to a July 2009 45

SPARKY’S REVOLT by Tony Coberly

Okay everyone, I’ve been busier than a one-legged wait­ ress at IHOP over the past month, so I’m forced to recycle a column from awhile back. But I have recently received several questions regarding multi- motor setups, so I’ve decided that this might be just the right time for a refresher. I’ve often been asked about the best and/or most widely accepted way to handle a multi-motor setup. Everyone who’s flown a multi-engine glow model will agree that one of the worst things that can happen with a twin is to lose an engine... to have one motor quit while the other continues 3 Cell Lipo 40 amp ESC 550 Size Brushed motor to run. But with electric motors Figure 1 this won't happen, right? Well, let's take a closer look. I’ll start with an old school, brushed multi-motor setup us­ ing 550 size can motors. Let's 3 Cell Lipo 40 amp ESC 2- 550 Size Brushed motors say we have a single 3-cell, Figure 2 3300 mah, 20C LiPo, and we throughout the flight, losing nition you have two points that run a 12x8 prop that burns 20 RPM at the same rate as the will wear, and eventually wear Amps on one motor, according battery voltages drops, and the out. The brushes themselves to our watt meter (see Figure ESC will shut down power are made of carbon, and make 1) . We can run both motors on when the pack voltage reaches contact with the commutator of a single ESC as long as it’s 3 volts per cell, according to its the motor to switch the polarity capable of handling 40 Amps programming. As long as nei­ of the armature and cause the minimum. Since our LiPo bat­ ther motor has a physical fail­ motor to turn. This contact be­ tery can handle 66 Amps, ure, we shouldn’t have to tween the commutator and the we’re okay there (see Figure worry about a motor failure. carbon brushes causes wear, so 2) This is a basic and simple What exactly is a “physical it is a known point of failure in setup that will power a reliable, failure”? Well, keep in mind time. This is a part of the rea­ twin-motor electric air plane. that we’re talking about brush­ son why, with brushed motors W e’ll have two motors that ed motors that have brushes. If we need to break-in the motors will run at similar RPM you have brushes, then by defi­ to make sure the brushes are 46 RC REPORT ONLINE

programmed to shut off when the pack voltage reaches 3 volts per cell (generally speak­ 1550 M a Hr Lí Po 35Amp ESC Brushless motor ing, of course), at which point Figure 3 the motor power is shut down, seated as smoothly as possible do know of several people who or at least it goes into a lower to the commutator, and there­ have done so, even though power mode. The settings vary fore provide the best possible sometimes only one motor will by manufacture, but just for current flow to the motor. We start! This is not what we want! example I’ll use a Castle Cre­ can see that there are benefits If we’re going to run two ations Phoenix 60 ESC as an for electric brushed motors for brushless motors then we need example. a multi-motor setup, but not an two brushless ESC's. Looking When the battery drops to 9 infallible option. at Figure 4 we see a single volts, one of the ESC’s will Okay, now let's look into battery powering two brushless shut down before the other. the more popular brushless ESC’s, and each ESC powers a This is a timing thing, and to motor options.. We’ll start with single 42mm motor. This is a expect two ESC’s that are poll­ the most logical option of using very acceptable configuration ing at over 20,000 times per the same 3-cell LiPo (3300 to power a twin electric model. second, to shut off perfectly mah, 20C) with a single brush­ What are the possible prob­ simultaneously, is simply not less ESC and one 42mm brush­ lems with this setup? None, did done. When one ESC shuts less motor. This single 42mm you say? Let's look again. At down, the other ESC will sud­ brushless motor with a 12x8 full throttle we have 62 Amps denly see a higher battery volt­ prop uses about 3l Amps (see being drawn with both motors age, because of the drop in cur­ Figure 3) Well, we know that running, and we’re having a rent. The higher voltage will our battery is capable of 66 great time flying for several naturally result in more RPM Amps, so we have just enough minutes with no problems. to that motor, which will result battery to power two motors. W e’re beginning to think about in a sudden and severe yaw But what about speed control­ landing, when all of a sudden resulting from the extra surge lers? Can we use one 60 Amp we notice a change in the in thrust on one side, coupled brushless ESC with two 30 sound of our motors. The we with a total loss of thrust on the Amp motors? Yes and no. Per­ get a sudden and severe yaw, other side. This all too often sonally, I do not recommend and down we go... dirt nap! results in a re-kitted model air­ using a single brushless ESC Well *%$%$%Λ#@@@Λ%! plane. for two brushless motors, but I What happened? Our ESC's are So, is this then not a good power system for a twin? No, this is a fine system to power our multi-motor model, we just need to use a timer to prevent using more than about 50% of the battery. Then we won’t have to depend on the ESC shutoff circuit. We should also size our battery large enough to give us the flight time we want, without depleting our battery to

35Amp ESC Brushless motor the point where it will trigger Figure 4 the ESC voltage cutoff. The July 2009 47

dropping the voltage to the point where the ESC reaches cutoff. 1550 MaHr LiPo 35Amp ESC Brushless motor We still have one more op­ tion for powering a multi-mo­ tor brushless model. We’ve established (I hope) that we need two ESC's for a twin, and we know that we can use one big battery to supply the power

1550 MaHr LiPo 35Amp ESC Brushless motor for both motors. Or we can use Figure 5 a smaller battery for each mo­ 3300 mah battery I referenced teries and two ESC’s. Each tor. But we can also use a hy­ is going to give us about 5-7 battery and ESC needs to be brid theory. That is, we can use minutes of flight time, depend­ capable of handling 31 Amps. multiple batteries in a parallel ing on our left thumb. If we use a 3-cell 20C LiPo, we circuit to power multiple mo­ What, only 5-7 minutes? need at least 1550 mah batter­ tors. Now folks, let's face it. Very ies. Having two batteries, we This begs the question, few people like to fly a twin can assume that they will gen­ "Why use multiple batteries in more than several minutes, so erally discharge at a similar parallel, instead of a single the 5-7 minute flight time is rate, and therefore reach cutoff larger one"? The answer is very usually enough. If is not, just voltage at approximately the simple... money! If we look at increase the battery capacity to same time, but not necessarily average cost per mah, we can gain the extra flight time. I’ll exactly the same time. Should see that the more popular size cover how to figure that out a one ESC reach the low cutoff batteries in the 1200 to 2000 little later in this column, but voltage before the other, (and it mah range are usually consid­ for now let's move on. Is this will), we’ll again be visited by erably cheaper than a single our only option for our multi­ the dreaded “one dead motor” larger battery. Also, if we’ve motor model? Well of course demon, and he just loves to been flying smaller LiPo's, we not! send models to ye old Dirt may have several similar suit­ W e’ll now look into a twin Nap. So we’re right back to the able batteries already, that will where we want to use a battery same issue where the pilot work well in our multi-motor for each motor and ESC in our needs to make sure there’s application. When I say similar model (see Figure 5). Using more than enough battery ca­ vintage, I mean that we have the same motor and prop setup pacity to fly for the minimum two or three batteries that as before, we’ll need two bat­ acceptable flight time without we’re using to fly smaller planes, and they have about the same number of cycles on them, and they hold about the same voltage levels over a flight (see Figure 6). By con­ necting two or more similar batteries in parallel, we can increase our battery capacity and keep our cost down... if we 1500+ MaHr LiPo 35Amp ESC Brushless motor already have these batteries. Figure 6 And they’ll still provide our 48 RC REPORT ONLINE

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Since 2001 Dishwasher Safe Microwave Safe Lasts for years Keepsake quality Pics on both sides into www.CupsAndStuff.com or 256-753-2682... see our other items... mousepads, coasters, etc. ESC’s and motors the power to add to one’s hobby box. I MORE HOSPITAL they need with a minimum of like MotoCalc from CHART BLOOPERS risk. Again, we still need to www.MotoCalc.com to give 1. Healthy appearing decrepit make sure that wherever possi­ me a good base line on current 69-year old male is mentally ble we do not drain the cells draw and flight time calcula­ alert but forgetful. down to the point where the tions. I’ve run several model 2. Patient had waffles for ESC reaches cutoff voltage. tests through this software, and breakfast and anorexia for How do we establish the it was within 95% accurate of lunch. flight times to expect? There is real world tests that I’ve done, 3. She appears numb from her some simple math that we can so I trust it. ElectriCalc is an­ toes down. do to give general numbers, but other that I’ve used (although 4. The patient has been de­ they’re entirely too general, not as extensively), that can be pressed since she began seeing and can be off as much as 50% found at www.slkelectron- me in 1993. at times. If we just figure the ics.com 5. The skin was moist and dry. current draw over a given Several motor and ESC 6. Occasional, constant infre­ amount of time, we’ll get a manufacturers provide basic quent headaches. number that looks good, but is calculators on their site for ba­ 7. Patient was alert and unre­ not very accurate. sic information. sponsive. Why not? Math is always 8. Rectal examination revealed accurate, but we also need to I hope this month's infor­ a normal size thyroid. figure in the efficiency of the mation about multi-motor 9. She stated that she had been prop, ESC, and motor. These power setup will help you in constipated for most ofher life, variables are overlooked more some way. Meanwhile, I wel­ until she got a divorce. often than one might think. I come your comments and sug­ 10. I saw your patient today, recommend that if you’re going gestions as always. Contact me who is still under our car for to invest in a large electric air­ and I’ll do my best to respond physical therapy. plane, say more than 15 size or quickly. 11. Both breasts are equal and any multi-motor electric, then Thanks for reading RC RE­ reactive to light and accommo­ spend a little money on the PORT Online! dation. electric motor calculation soft­ -Tony Co berly 12. Examination of genitalia ware for your computer. This 10017 Strong Drive SE reveals that he is circus sized. software costs anywhere from Huntsville, AL 35803 13. The lab test indicated ab­ $19 to $50, and are a great tool [email protected] normal lover function. ON IN E !

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Bird on a Wire by Terry Dunn

Last month’s column was a bit heavy with all the gloom and doom associated with lengthening ESC wires. Now I think we deserve some lighter fare, so I’ve been working on a couple of small projects that you may find interesting. I’ll share them with you while also inviting you to write to me about your own electric flight tinkerings.

One Hcli of a P-38 For whatever reason, the R/C helicopter bug has just never bitten me. I certainly can appreciate the engineering in­ volved, and I usually stare in awe when a good hcli pilot takes the sticks. I’ve just never felt the urge to own anything more than a simple chopper that I could fly in my driveway, copter, meaning that it has two transmitter and let them have a and that one collects a lot of sets of main rotor blades that go at it. dust. However, I am a sucker spin on a common axis in op­ So, after all this helicopter for a good deal, so I recently posite directions. This set-up chatter, you probably think that bought two more electric helis. negates the need for a tail ro­ one of the projects I mentioned A friend of mine was sell­ tor. Yaw control is achieved by earlier has something to do ing his E-flitc Blade CX2 and differing the RPM between the with choppers, right? Wrong! Blade CP Pro helicopters as a mainblades, causing the differ­ Well, okay... maybe a little. package deal. Now, I don’t ence in torque to swing the hcli But as I was sorting through really have any interest in the around. the box of spare parts included nimble CP Pro, but the price Co-axial helicopters are with the CX2, I came across a for the pair was just too good generally considered the easiest spare 4-in-l control unit. to pass up. I also figured I of all helis to fly, and I agree. “What the heck is a 4-in-1 could resell the CP Pro, which I’ve been having a good time control unit? ” I’m trying to do now. The with mine. I can fly it in the Well, I’m glad you asked. Blade CX2, however, is a good driveway or even in the living This one is a small plastic case fit for my interests and skill room without difficulty. I stuffed with a 2.4 GHz Spek­ level. It’s a co-axial type heli­ might even get the kids on the trum receiver, a built-in gyro, July 2009 51

and two Electronic Speed Con­ trols (ESC). (Note that newer versions of the Blade CX have a 3-ini control unit and a sepa­ rate receiver). All of these components work together to get the Blade CX2 airborne in a stable fashion. But here co­ mes the messy part... since the 4-in-l unit already on the heli­ copter was working just fine, what was I to do with the spare unit? I couldn’t just leave such Photo 1: A 4-in-l control unit from a E-flite Blade CX helicopter brought a neat little jewel unused! this abandoned. P-38 back to life. Having a 2.4 GHz receiver and two (Editor’s Note: If a friendly ESC’s in a small package makes it ideal for the 26.5” span Lil-Lightning. visitor from outer space were to drop down to Earth, hand Terry a hand-held device that would diagnose and cure all diseases and human ailments, saying “Give this to your lead­ er. ”, I ’m betting Terry would first take it apart to see how it worked!) So, I scanned my workshop looking for a quick and dirty project that could utilize these marvel of electronics. That’s Photo 2 :1 was hoping that the differential-thrust yaw control inherent to when my gaze met an unused this heli 4-in-l unit would have more control authority, but even so, the profile P-38. More specifically, Lil-Lightning is still a hoot to fly in calm airs. it’s a Foamtastic Models Lil- they’d work with the small didn’t have any adapters to Lightning. I built this model brushed motors in the P-38. mate the Deans Ultra Plugs on about four years ago, but after The only problem was, I could­ my Wattmeter with the JST flying it a few times, I hung it n’t find any documentation plugs used on the 4-in-l unit from the ceiling where it’s indicating how many Amps the and the 2-cell 800 mah LiPo been ever since, almost forgot­ ESC’s could handle. I sent an batteries that came with the ten. It still had the motors in email to the tech guys at Hori­ CX. So, rather than do the place though, so I knew I could zon, but as yet I’ve heard noth­ smart thing and build two get it airworthy again in no ing back. The smart thing to do adapters, I just did a little esti­ time. would have been to measure mating. Since the two ESC’s built the current drawn by the heli­ I knew that the Blade was into the 4-in-l unit are sized to copter at full throttle. Then I getting about eight minutes of operate the two 180-size brush­ could divide that number by flight from each fully charged ed motors in the Blade CX, I two, and I’d have a common battery. That works out to an first needed to make sure that sense limit for each ESC. But I average current of just over 6 52 RC REPOR T ONLINE

Amps total, or 3 Amps through each ESC (800 mah = .8 Ah, and eight minutes = .13 hour, so .8 Ah/.13h = 6.2 A). I’m sure full throttle current is a little more, but I knew I was safe there because the motors in the P-38 draw less than 3 Amps each with 3x3 props and the same 2-cell LiPo. Since the Blade CX uses Photo 3: The Slow Tow is the result of my effort to create a less- differential motor speed for intimidating form of aero-towing fun for rookies (and me). Cheap and yaw control, I was hopeful that simple are the key ingredients here. (David Bacque photo) I could get the same effect on RPM on twins don’t make Slow Tow is a simple GWS the rudderless P-38. I set it up much difference.) “Slow Stick”, perhaps the best­ so that left rudder input on the selling park flyer ever made. I transmitter would make the SLOW TOW see these things everywhere, right motor spin faster, and I’ve dedicated a significant and for good reason. They’re vice versa. And sure enough, amount of space in previous cheap, tough, and fun to fly. while holding the little plane in columns conveying the fun I’ve My Slow Stick has a mild, my hand, there was consider­ been having with aero-towing. brushless motor, but I’m sure able yaw effect. But there’s It’s provided a fun and chal­ that the stock, geared, brushed only one way to see what the lenging change of pace that has motor would work fine for true effect will be in flight! really invigorated my excite­ aero-towing as well. My first flight with the re­ ment for this hobby. The only The glider is a Lifoam “Ul­ vamped Lil-Lightning went problem is the overhead in­ tra Flyer” converted to R/C. well. It’s a little underpowered volved. My usual aerotow part­ The Ultra Flyer is one of those for my tastes, but it has enough ner, Lee Ray, lives on the op­ planes commonly referred to as guts to get where you want to posite side of Houston. We a “dime-store glider” or go. I’m willing to bet that it often have a hard time meshing “chuck-it glider”. There are could even be flown indoors in our schedules and whereabouts several similar versions avail­ a decent sized area. The P-38 is to pull off a meeting at the able at toy stores, Wal-Mart, also capable of loops, rolls, and field. It’s been hard recruiting etc for $5 to $10. I’m sure any all the basic 3-channel aerobat­ any of my other flying buddies of them would work. I only ics, but now it’s a 4-ch bird, so into the aero-towing cult, even chose the Ultra Flyer because I what about that differential- though I have all the needed already had one. thrust yaw control? Unfortu­ equipment. I’ve found that Converting the Ultra Flyer nately, it doesn’t seem to have most folks are reluctant to try to R/C was a simple matter of much effect in-flight. I plan to aero-towing with somebody adding a sheet foam rudder and play with it some more, but so else’s planes, even when I goad elevator, along with two servos far that’s been my only disap­ them. So I set out to build a to control them. The receiver pointment in this project. smaller, less intimidating, and and 4-cell 250 mah NiMh bat­ (Editor’s Note: This tends to more inviting aero-tow duo. I tery are placed toward the nose support Ed Moorman’s find­ call it the “Slow Tow.” for proper CG. Thus far I have­ ings that slightly mismatched The tow plane side of the n’t found the need to glue in July 2009 53

On the glider side, another paperclip is bent into a hook shape and taped under the nose of the plane. The paperclip on the aft end of the tow line loops over the hook. Under tension (while towing) the two paperclips stay engaged (well, most of the time). When power on the tow plane is chopped, a little wiggling of the glider is usually enough to free it from the tow line. I don’t see how Photo 4: Common household items are used in the Slow Tow’s tow line. R/C aero-towing could get A craft stick and paperclip attach the line to the GWS Slow Stick tug. much simpler, cheaper, or less Don’t forget the swivel! intimidating than this! My first outing with the Slow Tow was a good learning experience. The first thing I learned was that some guys were still reluctant to fly my humble little Slow Stick! Yet, no one had any heartburn over taking the sticks of my $5 glid­ er! I’m not sure whether to be relieved or offended! Another thing that we soon learned was that swivels on the tow line are absolutely manda­ Photo 5: More paperclips are used on the glider’s end of the tow line. The passive “hook and loop” attachment system seems to work well. tory! I’ve always used them on my big tow line, but I thought I the wings, but I did add some ment fishing line, carefully and could skip them here. Well, I dihedral to the outer 12" of scientifically chosen (i.e., be­ thought wrong. Once the glider each wing panel. Without the cause that’s what I had on is released, the tow line quickly dihedral, rudder input would hand). Small streamers made of spins itself into a spaghetti only make the plane yaw with­ tape add visibility to the ends bowl of tenacious knots which out banking or changing direc­ of the tow line, and a paperclip both shorten and weaken the tion. Adding the tip dihedral tied to each end provides a re­ line. We managed to deal with was an easy fix. Note too that movable attachment point. the knots that first day, but I’ve the wing has no spar, not even On the Slow Stick, I pass since added swivels at both tape. It’s important to keep the paperclip through a pop- ends. things as light and simple as sicle stick and nuzzle the stick The very first flight was possible. under the rubber bands that quite eventful. I flew the Slow Connecting the two planes secure the wing. It’s a simple Stick while Randy Stone flew is about 30' of 4 lb. monofila­ and forgiving setup. the glider. I fed in about 1/4 54 RC REPOR T ONLINE

win any thermal duration con­ tests, but it has the “fun per dol­ lar” category nailed! The next glider pilot was David Bacque. By this time, the tow line was a short, twist­ ed mess, making the glider a little harder to fly under tow. We got off the ground okay, and made a nice, coordinated turn, and headed downwind. Between the two of us, we somehow got the glider into a full stall which pulled down the tail of the Slow Stick. Photo 6: No need for a high-end molded glider here. A $5 ‘chuck-it glider’ There we were, about 100' converted to R/C provides plenty of low cost fun. high, with the Slow Stick per­ fectly vertical and the glider hanging motionless and help­ less from the tow line. Full power on the tow plane was just enough to keep us in place, but it was obvious that we couldn’t stay that way forever! I later joked with David that he was probably the first modeler to ever hover a glider! After several seconds of Photo 7: If you’re thinking that this doesn’t look quite right, you’d be slack-jawed gawking at this correct. A botched tow resulted in both planes in a temporary tethered hover. A quick dive by the tow plane released the tow line and created this awkward predicament, I gave unusual pose. Just another example of scampy aero-towing fun. the Slow Stick full up elevator (Randy Stone photo) and raced toward the ground. throttle, and both planes were es, I doubt that we’d ever rec­ Only after passing the glider off the runway in just a few reate that slow motion mid-air! did I pull out of my power feet. About 200' out and 50' up, Fortunately, neither airplane dive. This move detached the we both got a little too squir- was damaged (such is the beau­ glider and allowed David too rely on the rudder, so the glider ty of minuscule momentum). make a fine landing. In the came off the tow line too early. Once we stopped laughing and meantime I had a new problem We turned our respective regained our composure, we on my hands! planes back toward the starting were able to get back to more My rudder pushrod had point. We took different paths, aero-towing. After a few more come loose from the servo dur­ yet somehow, we both arrived unintended releases, we finally ing my violent, evasive action, at the same place at the same accomplished a good tow. so I could no longer steer my time, about 3' above the run­ Still, even the botched attempts plane. Thankfully I still had way! Given 1000 more chanc­ were fun. The glider will never elevator and throttle control, so July 2009 55

Photo 8: Bill Schwander’s UC-78 Bobcat is coming along, but it’s far from complete. No doubt she’ll be a beauty, though. Note the transmitter under the nose for size reference. through a series of wild Immel- has just about reached that event has come and gone, so mans, stall turns, and frantic point. Most of the framing is now I’m prodding him to finish body contortions, I finally got done, but there are still count­ it before the local BEST event the Slow Stick pointed my way less little details to attend to in October. I’ll let you know and landed, Thus ending the before he’ll plug in his cover­ when it’s ready to fly. world premiere of the Slow ing iron. Most recently, he built I’ve already begun working Tow. If the rest of my outings a vacuform rig so he could pull on something really fun for are even half as eventful (and his own plastic canopy. Bill next month’s column, and I enjoyable) as the first, then attached one of his early can­ think you’ll enjoy it. So, until I’ve got a real winner here! opy attempts to the Bobcat for then... -Terry Dunn the photo you see here. The [email protected] BALSA BAMBOO BOMBER original plan was to have the 15510 Penn Hills Lane A few of you have written plane ready for SEFF, but that Houston, TX 77062 to us asking the status of Bill Schwander’s scratch-built Some things never go Cessna UC-78 Bobcat. Well, out of style. Saving it’s coming along nicely. They money is one of them. say that once an airplane is www.rtlfasteners.com ready for covering, it’s about aöten eta 1-800-239-6010 50% complete, and I think Bill 56 RC REPORT ONLINE

AERIAL BANNERS 101 by Dick Pettit

While searching through quite differently than full scale gain enough airspeed to get my cabinets and shelves look­ banner towing. The full scale both the plane and the banner ing for an item I needed, I guys snag the banner from the airborne! This too is not the came across something I’d ground using a hook attached recommended method for ban­ made many years ago but had­ to a line that’s attached to their ner towing with an R/C model. n’t used (or even seen!) in a plane. They then tow it around I roll up the banner, attach long time. It was an old banner for a while, and then drop it it to the plane under the fuse­ that I’d made for towing be­ back at the field, after which lage, and carry it aloft in a roll. hind some of my large air­ they might even pick up a dif­ When I’m ready to unfurl it, I planes. Finding that banner ferent banner and do it all over flip a switch and the banner sure brought back some pleas­ again. That method is not very unrolls in the air stream, often ant memories of the days when conducive for R/C models, amazing spectators. “Where id I’d haul that banner up and do mainly because we might miss the banner come from?” I’ll a little promoting at local fly­ the banner hook completely, or later flip the switch again to ing events. It also reminded me we might snag something other drop the banner from the plane, that over the years, several of than the banner, like the allowing it to flutter gently to our readers have asked about ground itself! the ground. banner towing, both for large I’ve seen some banner tow­ First you need to figure out and small airplanes. This just ing models that can pull the how large a banner you can may be the right time to tell banner up from the ground on tow and be able to read in the you what and how I do it. takeoff, but doing it that way air for the size plane you’re First I want to explain that can be problematic due to using. My 1/4 scale Cub with a banner towing with model air­ snagging the banner on the 20cc gas engine can easily tow planes should be carried out ground, or not being able to a 15' long 16" wide banner on a July 2009 57

blank material at the tail end because it will flap in the breeze, hiding any lettering there. The front end of the banner, as seen in Photo 2, is a 3/8" dowel to which I used hot glue to fasten the mesh banner, after wrapping it a turn or two. I then use 40 to 60 lb. test fish­ ing leader wire for my tow leads, usually about 20' long for my large planes. Attach a length of leader to the banner dowel about three times the dowel’s length, using crimp sleeves or ferrules. The attach­ Photo 1: Banner material and lettering ment point for the tow lead is about 1/3 the length of the wire from the top. Now let’s build the tow and release mechanism. We’ll need a plane with at least 3-4M of ground clearance because the banner will be carried under the fuselage and you don’t want it to snag on the ground. We’ll need a piece of 1/4" hard brass tubing about 3" long, as seen in Photo 3. The lower slot is about 1/4" from the bottom, and the other slot is 1/2" above Photo 2: Front end of banner showing harness wire that. Cut these slots about half­ 25' leader wire. I’m guessing servo positions to carry, unfurl, way through the tubing, and that a strong .40-.60 size model and drop the banner. about 1/8" wide. could tow a banner maybe 5' I make my banners from a Now drill a 1/4" hole long and 6" wide, but banners nylon mesh material found at through the bottom of your that small can be difficult to fabric stores, as seen in Photo plane, preferably through a read even at a moderate alti­ 1. It’s all white with 1/8" open­ piece of hardwood like a land­ tude. ings in the mesh. It weighs next ing gear block. This hole needs You’ll also need to use a to nothing and you couldn’t rip to be drilled at or near the bal­ transmitter with either a three it barehanded if you tried. ance point of the plane and be position switch that controls a The lettering is made from sure that there’s enough room separate servo, or a propor­ lightweight black nylon mate­ inside the plane to mount a tional channel controlled by a rial cut into the letter shapes servo near the hole. Photo 4 potentiometer. In other words, and hot glued to the mesh. Be shows a mock-up of the com­ you need enough different sure to leave a foot or two of plete release mechanism in- 58 RC REPORT ONLINE

This is another reason I like to fly large models because there’s always lots of extra room inside the fuselage for things like banner towing mounts. If there isn’t a suitable hardwood part at this location, glue one in and drill your hole through it. You want a good bit of support for the tube when pulling backwards on it.

··...... 'Ji&SaMíAn·^. Attach the hard brass tube through the hole in your fuse­ Photo 3: Parts of release mechanism inside fuselage lage with a drop of thin Zap, making sure the slots face to the rear of the plane. Install a servo with an arm that’s about 1" long so that the end of the arm is directly over the hole in the tubing inside the fuselage. Double-sided foam tape may work here, but you may want a t · more permanent installation. Set up the control of your servo as follows: You’ll want the first position “down” to look like Photo 5, the second Photo 4: Mock-up of release mechanism showing servo, tube, wire, position “middle” should look and fuselage bottom. like Photo 6, and the third po­ sition “up” should look like Photo 7. There needs to be at least 3/4" of movement be­ tween position #1 and position #3, so set your servo travels accordingly. Bend up a piece of 1/16" music wire with a Z-bend at the servo arm end, making it just long enough to get it even with the bottom of the tube at the “down” position. The “mid­ dle” position should allow the wire to clear the lower slot but not the upper slot. The “up” Photo 5: “Down” position of servo when taking off position should allow the wire to clear both the lower and up­ eluding the simulated fuselage brass tube, and the release per slot completely. It sounds floor, servo mount, the hard wire, all to be described later. complicated, but once you get July 2009 59

circumference of the rolled up banner. Make another loop in the lead wire at this dimension behind the first loop and secure with a crimp sleeve. These de­ tails can be seen in Photo 8. Here’s how to attach the banner assembly to the release mechanism. Roll up the har­ ness and lead wire over the rolled up banner until you get to the loop that’s not at the very end. With the release servo set at the “up” position Photo 6" “Middle” position of servo after unfurling banner (the wire is clear of both slots), insert this loop into the upper slot and move the servo to the “middle” position. If all is cor­ rect, the banner will now be attached to the plane but will unfurl if the plane is flown. Now, wrap the rest of the lead wire around the rolled up ban­ ner and put the end loop into the bottom slot. Move the servo to the “down” position, which should keep the banner attached to the plane without Photo 7: “Up” position of servo after releasing banner from aircraft dropping. Refer to Photos 5,6, and 7 for more details. Here’s how the release mechanism is supposed to work. With the drop servo in the “down” position, you can get your plane airborne. At a safe altitude, you can move the servo to the “middle” position and your banner will unfurl and open up in the air. The part of the lead wire that wraps around the rolled up banner gets dis­ Photo 8: Details of front end of tow lead showing two loops connected and the banner de­ the idea of what we’re trying to esting. Make a 1" long loop in ploys to the rear. If you move accomplish, it willbecome eas­ the front most end of the lead, the servo to the “up” position, ier to comprehend. securing it with a crimp sleeve. the banner becomes discon­ At the front end of the tow Now, roll up your banner start­ nected from the plane and the lead, it gets a little more inter­ ing at the rear and measure the banner falls to the ground. Be 60 RC REPORT ONLINE

Photo 8: Details of front end of tow lead showing two loops sure to do this over the flying release mechanism. It’s called tissue, and they can go diving field unless you like to climb the “Delsey Dive” and it will toward it. In that case, try to trees. certainly be the hit of your next steer clear of those other planes Photo 9 shows my Cub air show. Rather than attach because it will get crowded towing a banner around the your banner to the release fix­ really quickly. field during a flying event. If ture, get a half-used roll of toi­ Happy Towing! -Dick Pettit you look closely under the let tissue and attach it to the [email protected] plane, you may be able to see release using a long rubber the piece of tow cable that was band. When you take off and wrapped around the banner get to a very high altitude, re­ during takeoff, but is now lease the tissue roll, allow it to hanging free. While it would unroll and then you can “dive” be nice advertising for Gordon, toward it, trying to cut it with you can choose to write what­ your propeller. That’s where ever you wish on your banner. the name “Delsey Dive” comes By the way, there’s one from. Or you can ask several more thing you can do with other pilots to get their planes your newly installed tow and in the air before you drop the

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FUN AEROBATICS by Ed Moorman

MANEUVER OF THE MONTH inside Square Loops Some maneuvers have names that make them sound harder than they really are. This month’s maneuver is one, the Inside Square Loop. You’ve probably never thought about doing one, but believe me, you'll like it, and nearly any powered R/C airplane can do one.

DESCRIPTION An Inside Square Loop is a SAFETY FIRST should be started while flying loop with four fairly small ra­ Square loops can put a lot upwind (into the wind). dius corners and four short, of stress on your wing, espe­ straight legs in between. The cially if you're yanking hard on WHAT TO DO corners don’t have to be really the elevator. If you aren’t sure Line up in your standard sharp, just tight enough to dis­ about the strength of your wing setup and start. After you pass tinguish them from a round joint and dihedral brace, no in front of yourself, begin cor­ loop. Inside Square Loops may matter whether it’s a kit or an ner 1. be done with up-elevator, or ARF, reinforce it or take it real Corner 1: Use about half­ Outside Square Loops done easy. Even with reinforcement, stick to start with. Don’t over­ with down-elevator. To do an some trainer wings will not do it and yank full up. This Inside Square Loop, you make take this much stress. If you're only scrubs off a lot of speed four fairly tight, up-elevator not sure, let a local expert in­ that you may need to climb to corners, and you're done. It spect your plane and give you the second corner. Your corner couldn’t be much easier. his opinion as to whether it’s should be tighter than a regular Don’t overdo it! You don’t capable of doing squares with­ loop, but not so tight that the need to jerk full up-elevator. out coming apart. Aero planes plane slows down too much. You're better off being nice like the Sig 4-Stars, aero train­ You’ll just have to try it with and smooth. ers like the Easy Sport, and all your plane and see how much fun fly planes will have no elevator is best for your plane. SETUP trouble with square loops. If you have a plane with great You need a normal amount vertical power (and a strong of up-elevator and enough THE STANDARD SETUP wing), then go ahead and use power for a short, vertical leg. 1. Use full power full up. As I said, most planes can do 2. Fly parallel to the runway one. You just have to train your 3. Fly one mistake high. fingers. The Inside Square Loop 62 RC R EPOR T ONLINE

you’ll never recover the top ______RC REPORT MAGAZINE inverted leg. TEACH YOURSELf I INSIDE SQUARE LOOP The Inverted Leg: You're AEROBATICS č á r o B y Ed Moorman going to be at a fairly slow ______DESCRIPTION OF THE INSIDE SQUARE LOOP______speed here, so if your plane A square loop is a loop with short, straight legs and four fairly flies inverted slightly nose up, small radius corners. The corners don’t have to be sharp, just tight enough to distinguish them from a round loop. Square loops may this is the attitude you want to be done inside with up elevator or outside with down elevator. To be in. If you keep the legs short do an inside square loop, you make four fairly tight, up elevator and stop the corner slightly corners and you have one. It couldn’t be much easier. Believe it or not, most planes can do them unless they are very under powered. nose high, you won’t need any ______KEYS TO DOING THE SQUARE LOOP______down elevator. For longer legs, DON’T OVER DO IT! You don’t need to slam in up elevator. You are use a little down to keep the better off being smooth.______nose from falling. Fly as far as AIRCRAFT SET-UP FOR DOING THE INSIDE SQUARE LOOP your up leg, and then make You need a normal amount of up elevator and enough power for a short vertical leg. As I said, most planes can do one. You just have corner 3. to train your fingers.______C orner 3: You may want to ______SAFETY FIRST______throttle back before this corner. Square loops put a lot of stress on your wing and can cause it to Use half up-elevator or a little fail in the middle. Be cautious. Check the center wing joint and the spars of your plane first.______less for this corner. ______STANDARD SET-UP______The Down Leg: If you're 1. Full power. making a big square, throttle 2. Parallel to the runway. back because the plane will 3. One mistake high. All loops are best done INTO the wind.______FLIGHT DIRECTION______gain a lot of speed depending Start the square loop while flying into the wind.______on the length of the leg. If your ______DOING THE SQUARE LOOP______square loop is fairly small, you -Do not jerk in full up elevator control for this maneuver. It should won’t need to reduce power. be done smoothly. As an example, on my Big -Use around half elevator control for corners to start. Use more control later if your plane has the power and the wing strength. Stick 40 with a .46, I don’t -The size of your square loop depends on your plane’s power and need to reduce power. This leg weight.______also takes less time due to the THE UP LEG pitch prop. A 10x6 seems to be increase in the speed. Watch it The vertical up leg of the the popular choice for most .40 or you’ll end up a lot lower and square loop is the one yoiTll size engines, but you might try much faster than you started. need to adjust depending on the an 11x4 to sec if you get a little Corner 4: This is what I call power of your plane. Pilots more climb. the “coffin corner”. If you're with hovering 3D planes can Corner 2: Make your sec­ too low, look out! If you let the go as far as they like. Guys ond corner a nice and easy one, speed build up too much, you with trainers need to see how using about half stick. Here’s a can overstress your plane. The far the plane will go upward, tip: Don't rotate a full 90° at key thing to remember is that and then start the second corner corner 2. Think about how your the legs do not take the same at about half that height. You'll plane flies inverted, especially amount of time. The down leg need a little speed on the top at slow speed. If it flics in­ to corner 4 goes very quickly leg so the plane doesn’t wallow verted slightly nose up, stop because you're going straight around while you’re inverted. your second corner at that an­ down, maybe at full power. If you're having trouble doing a gle. Remember, you're going to Time the bottom, use half up square loop with your trainer, be flying fairly slowly here, so elevator, and level off, adding you might want to try a lower don’t let the nose drop, or the power back in if necessary. July 2009 63

A light, powerful plane can do a large square. Lower powered now I’d be hard pressed to planes should do smaller squares.______think of a twin that flies better. Corner 1: As you pass in front of yourself, pull up to vertical. Do The old Pica Duelist is popular not yank in the elevator______The Up Leg: The length of the up leg determines the size of the too, but I've never flown one. whole square loop. Fly vertical a comfortable distance for your Anyway, I ordered a second kit plane. Lower powered planes will have to fly a shorter leg for a after flying my first one. If I smaller, tighter square loop.______managed to bash one, I wanted Corner 2: Make an easy corner here because your speed has slowed in the vertical climb. Level off slightly nose high.______another one real handy. Fortu­ The Inverted Leg: Hold a little down to keep the plane level nately, I still have the first one, inverted.______so the second kit was never Corner 3: You may want to reduce power before this corner. Make needed... until now. this an easy corner. The plane will drop to straight down quickly. The Down Leg: This leg doesn’t take much time. Even at idle power The Twin-Air is an excel­ the speed builds quickly.______lent kit, CAD designed and Corner 4: Don’t overdo this corner. Due to your speed the g’s will laser-cut, so everything fits be high. Add power back in after you level off.______perfectly. You may need a I didn’t really want another little down inverted twin right now, and I felt sure /■ > Throttle 3 2 that Flaps could make some­ back, if thing interesting from the kit. necessary Use less Both he and I like non-conven- than full up tional airplanes, so I figured for corners 4 1 why not a flying wing? He said i.______2 a flying wing wasn’t odd Try to end at same altitude as enough, and he’d already done the start lots wings and deltas already. I

CLIP OUT-TAKE TO THE flELV kept bugging him about it, COLLECT THE WHOLE PC REPORT SEKIES though, until he finally gave in For reprints of Fun Aerobatics or back issues call and agreed to it. I knew that _____ R/C Report magazine: (256) 539-3031_____ once he got CA on his fingers, Ed Moorman E-mail: [email protected] he'd be hooked and finish the job. Photo 6 shows the normal Okay, that wasn’t too hard, ery old movie there is, often Aerodynamics Twin-Air 45. was it? Now all you need to do twice, and some many times. I is get out there and practice. needed to get him out of his Basic Design Modification lethargy, so I was trying to For the basic design of a FEATURE OF THE MONTH think of a project for him when flying wing, you need to start Flaps builds a Wing-Air 75 I remembered that I had an with the CG a good bit forward In last month’s teaser pre­ extra Northeast Aerodynamics of where you would normally view I told you about talking Twin-Air 45 kit. You may re­ balance. A good rule of thumb Flaps into building a single­ member the March 2005 issue for flying wing CG's is 10% to engine flying wing from a con­ where I did a mini-review on 15% of the average chord. ventional, twin-engine kit. This this kit. Later on we converted We'd normally use 25% to 30% is a built-up kit, not an ARF. it to a triple by adding an en­ for a conventional plane. Flaps was “bored to tears,” gine in the nose! Then you need a reflex air­ as he put it, and reduced to The Northeast Aero Twin- foil, or you have to add some watching daytime soap operas -Air is one of the best flying reflex to the airfoil you have. on TV. At age 87 he's seen ev­ sport twins out there. Right Let me explain: The lift of a 64 RC REPOR T ONLINE

gives you the right amount of up-elevon. You may remember the October 2007 issue of “R/C Report” magazine in which Flaps and I sawed the stab off an old Goldberg Extreme 330 to make it into a flying wing. We adjusted the elevens (the former ailerons) up about/4" to give the needed reflex. In­ flight trimming later resulted in the exact amount needed. After predictions of disaster from Photo 1: Young Daniel DeMaria with his father’s kit built 4-Star Ugo and others, we proved 40. Frank uses an Evolution .46 for power. Great colors and trim them wrong. The model flew design! Frank later told me he pulled the engine and radio to put great. in a Kaos since it flies better. I loved the Kaos. I built 4 of the original ones and a couple of the Tower ARFs. Frank’s is the old Kaos Jr, original 40-size, built from RCM plans. Twin-Air Kit Modifications Wing: You can build the wing normally but without the twin engine nacelles. This works just fine as the nacelles are normally added after the basic wing is built. I did want one mod for safety reasons, however. I lost a delta with elevons when one of the ele­ vons failed. It was either the servo or the linkage, which left me with no control on one side. Any attempt at up elevator then resulted only in roll. There was nothing I could do but throttle Photo 2: Jorge Estrada with his Su-31. Jorge uses a Thunder Tiger .75 4-stroke in it. He originally had trouble with the engine leaning back and watch the crash. For out and quitting, but found he had fuel foaming. With a little extra this reason I asked Flaps to cut foam around the tank, the engine turned out to be a sweetheart. the elevons into two pieces and use four servos. This way if wing on an R/C airplane acts something else to counter the one fails, I'll still have some rearward of the center of grav­ forward rotation of the wing. control. So delete the nacelles, ity. This makes the wing want To do this we generally raise build the wing by the plans, but to rotate forward, or nose both elevons slightly. This use four elevon servos. down. The horizontal stab pro­ forces the rear of the wing Fuselage: Since the kit is a vides a downward force, coun­ down, countering the natural twin, the nose is a solid balsa tering the wing's nose down rotation. You simply make an block to be carved and sanded tendency. We don’t have a hor­ educated guess of the correct to shape. This needs to be re­ izontal stab on a flying wing, amount, and once in the air you moved and an engine mount though, so we have to provide trim the plane to fly level. This installed. Northeast Aerody- July 2009 65

stock fuselage off at the bulk­ head that's mid-way back be­ tween the trailing edge of the wing and the leading edge of the stab. I told Flaps not to worry about tapering the new, shorter fuselage, but to deco­ rate it like a jet exhaust. So delete nose block and cut the rear fuselage off at mid point. Fin and Rudder: Normally, if you shorten the fuselage you'll want a slightly larger fin Photo 3: Ugo Ferrari has hung up his Tower Trainer and is now flying this new Great Planes Escapade. It only has 462 square and rudder to compensate for inches of area, so the OS .40FP he used is an excellent match for the lost fuselage side area. For the plane. Does anyone else miss the OS .40FP? Ugo let me give it this project I asked Flaps to a try and it’s an excellent flying plane and only $99.99. move the original fin and rud­ der forward on the shorter fu­ selage, and I’d give it a try like that. The tail is already a pretty good size, so if there was any yaw instability, I figured it wouldn't be much. Besides, we can add to the size of the fin later on if needed. So, move the standard fin and rudder forward on the shorter fuse­ lage. Northeast Aerodynamics’ kits are laser-cut and feature top quality balsa. Flaps’ said the kit has “good lumber.” The kit includes landing gear and the regular kit hardware. Flaps and I usually replace at least Photo 4: Jon Kline and his Hangar 9 Funtana 40. It uses a half the hardware, but that in Magnum .91 4C for power, so it doesn’t lack speed and vertical. the kit will work. The wing ribs of the Twin- namics also sells a .60 size was a very nice 3/8” plywood -Air are semi-symmetrical with single-engine kit with an al­ firewall. Flaps wouldn’t even a flat bottom from the main most identical wing and fuse­ have to cut out a firewall for spar to the trailing edge. This is lage (same span and length). this model. the same design as used on the The twin gets nacelles and a Naturally, the stabilizer has original Ugly Stick and the big balsa nose block. The sin­ to be removed to have a flying newer Uproar kit. It means you gle gets an engine mount on wing. To help us get the bal­ can build the wing flat on the the nose. I checked the plans ance without a lot of work, I table, making it easier to align and right behind the nose block decided that we should cut the everything and keep it warp 66 RC REPOR T ONLINE

the basic fuselage is pretty stur­ dy. The top of the fuselage is designed as an all-balsa, cabin- -like structure with a wind­ screen and turtledeck. Tongues on the bulkheads fit nicely into laser-cut sockets in the sides, making for a strong, straight fuselage. Some carving is re­ quired to round off the edges, but this is minimal. Frankly, I think and Flaps agrees, that a little whittling does a man good, so we never mind this part of construction. Many of you will probably remember back when you were a kid, you would sharpen your pocket knife and just whittle on a stick Photo 5: John McGowan and his Air Devil combat plane named with nothing particular in “Bitch Slappin9 Mama. ”John likes the Magnum .15XLS for power. mind. I know I did. Flaps chopped the fuselage off just aft of the center fuse­ lage bulkhead between the wing and stab. Next he cut a new slot for the fin in the top of the turtledeck. Since this is a flying wing, the stab isn’t re­ quired. The supplied nose gear mounting block is bolted to the rear of the firewall. This lo­ cates the steering arm under the fuel tank. A bottom hatch is provided to make it easier to get the tank in and out, and Photo 6: Ed and Flaps’ Twin-Air 45. This kit was the basis for the also to adjust the steering arm. flying wing detailed below. I had a Tower .75 engine free. The instructions are ex­ two panels with 30-minute ep­ available that had been broken cellent and there are plenty of oxy and fiberglass cloth. in but never flown. My other pictures. One thing Flaps said The fuselage is a simple, Tower .75 is in a Pole Star fly­ that the instructions stressed slab-sided box, so the construc­ ing wing. It ran so well I several times was keeping the tion is very easy. There's a bought a second one, but never wing straight. After starting, it 1/16” plywood doubler from got around to using it. It should didn’t take Flaps long to finish the wing trailing edge to the be good power for this model, framing up the wing panels firewall, and 1/4" balsa doub­ and hopefully give us a good using thin CA and joining the lers in the wing saddle area, so bit of speed. Juty 2009 67

quency), four Bluebird 630 standard servos for elevons, one Hi-Tec 5625 digital servo on the rudder, and a Bluebird mini servo on the throttle. Friday, I dropped over to Flaps’ shop to set up the radio controls on the Wing-Air. I took one look at the finished plane and said, ”Whoa, buddy, that thing is bright!” “You said you wanted to see it,” he answered. I'd told him earlier that I wanted an easy to follow plane in flight, and he sure gave me one! Photo 7: Ed and his Wing-Air 75 prior to the test flight. Photo 7 shows me with the Wing-Air 75 flying wing. The other thing I noticed was that it looked very short and stubby, and not very esthe­ tic. “Looks to me like you took a plane and just cut the fuse­ lage off,” I commented. “That’s what you told me to do”, he replied. And he was right. Photo 8 shows the Wing- -Air from the side. For the elevons I needed to set my JR 9303 Wing Type feature to “Delta” or “Elevon.” I'm using four eleven servos for safety reasons, so I decided to keep it simple. I used a Photo 8: The Wing-Air 75, left side. Y-harness to connect the two There was no engine mount both sides, one over the engine left servos together, and a sec­ included, so we chose a Great and a matching one on the ond Y-harness to connect the Planes adjustable mount. We other side. Before I could even two right servos. Once this is like this one because it allows ask, Flaps said, “Don’t worry, done, the right wing servos us to change engines later with­ I know you’re a nut on cooling, plug into the elevator channel, out drilling new holes in the so the inlet and outlet are big. and the left wing servos plug firewall. Besides, I already had That engine won’t overheat.” into the aileron channel. The one that was drilled for the en­ The cheek cowl additions and a transmitter’s programming al­ gine we were going to use. 2-1/2" spinner dress the nose. lows the controls to work to­ The engine is side mounted, We're using a JR 9303 gether for elevator or pitch so Flaps decided to get fancy transmitter, a JR 770 PCM re­ control, and opposite for roll or and add short cheek cowls to ceiver on 50 MHZ (ham fre­ aileron control. 68 RC REPORT ONLINE

This is a flying wing, so the airfoil needs reflex. After I got Some things never go the dual rates set, I used the f out of style. Saving Sub Trim (center adjust) fea­ money is one of them. ture to raise both elevons about www.rtlfasteners.com 1/8” above neutral. I figured 1-800-239-6010 J JLTtener* this would be a good starting point until I get it trimmed. used a flex cable and the steer­ that it was too heavy on the Since Flaps used a pull-pull ing arm was fairly flexible. nose gear. Duh! I should have cable for the rudder, he wanted Between the steering arm and thought of that during con­ to use a separate servo for nose the flex cable, I could turn the struction! The gear is in the wheel steering, so another JR nose gear by hand pretty easily. stock location, which is fine for 9303 was added, mixed with Flaps said he could fix it, but the normal CG, but the forward the rudder channel. he wanted to take it home and CG of a flying wing places Saturday was cloudless do it right. I’m a band-aid type, more down-force on the nose. with only a light breeze, so it full power and go-for-it guy at This would require a major was a great day for flight test­ the field, so Flaps has to hold fix. We have to move the main ing. Flaps and I assembled the me back at times. I knew he landing gear forward. I’ll have Wing-Air, did a range check, was right this time, though. to get a good check on the CG and tried out all the controls. The plane didn’t have a scratch and move the landing gear After starting and tuning the on it except for the scuffed tips mounting blocks, or add new Tower .75, we were ready to of the Master Airscrew prop. ones, which might be easier. go. I taxied out, turned into the We agreed to pack up, take it An inch behind the CG ought wind, and eased in the power. home, fix the nose gear right, to be about right. After about a 20' roll, I started and try again next weekend. I So, I can’t give you a flight easing in some back stick. The then settled for flying his report just yet, but that’s how it nose gear suddenly turned 90° scratch-bui It scale Fairchild 24. goes with original designs and and the plane nosed down, kill­ On the following Sunday I heavy conversions. This is es­ ing the engine. Rats! was primed and ready to fly the pecially true for unconven­ We brought the plane back Wing Air. Flaps had changed tional planes like flying wings, into the pits, sat it on the work the nose gear linkage to a solid deltas, and canards. Hopefully, table, and took a close look. wire that was much stiffer. I I’ll have a flight report next The nose was angled a little bit swapped the nose wheel for month. -Ed Moorman low. It wasn’t really noticeable one a 1/2" larger, thus raising 85 12 th Street when the plane was on the the nose 1/4". Shalimar, FL 32579 ground and you were standing With the model on the run­ moormanl @c ox.net up, but it was clear sitting on way and aimed into the breeze, the table. This caused the I added power. It was tracking The last of the... model to push down on the fairly straight, so I added some HOSPITAL CHART nose gear as speed increased. It up elevator. Then I added some BLOOPERS was easily fixed by extending more, then more. When I was 1. The patient’s skin is some­ the nose gear a little, or we holding full up-elevator and the what pale but present. could have installed a slightly plane was still glued to the run­ 2. The pelvic exam will be larger nose wheel. way, I shut it off and aborted. done later on the floor. Next we flipped the plane Double rats! Now what? 3. Patient has two teenage chil­ over and removed the lower Flaps, I, and several other dren, but no other abnormali­ hatch. The nose wheel steering guys discussed it and decided ties. July 2009 69

HERE'S HOW... by Walt Wilson Share your best ideas and building tips with others. Send your "Here's H ow..." ideas to... Walt Wilson, 3000 Persimmon, St. Charles, MO 63301 or by email to... [email protected] Please include your full name and mailing address. The first submitter of any idea used here will win a Two-Year subscription or renewal to R/C REPORT ONLINE. If the subscription or renewal is to be a gift to some­ one else, please state this when submitting the idea.

SCREW ASSEMBLY 1. Mark Immonen of Ann Arbor, MI, had the problem of losing the washers on the little bolts he found another use for it. He was always that fasten the wing struts to his models. He losing track of small engine parts on his messy cured the problem by cutting a piece of dis­ workbench when performing repairs. Now Mark carded, flat plastic from a product package (or uses a Sharpie pen to label the pan's cavities to any scrap plastic of suitable thickness) into isolate and keep parts from mixing, such as washers. First drill holes in the plastic just a bit valve train parts, etc. He makes notes on the pan smaller than the outer diameter of the bolt. Then where necessary, for parts orientation. Clean up cut out the washers and thread them onto the is easy with a little alcohol, which gets rid of any bolts. If the plastic washers are an easy, slip-on oil residue and the old notes. If he can't get fit, they won't stay on any better than the original complete the engine work right away, the pan washers. You may have to repeat the process can be easily stored with all the parts identified every once in a while, as the plastic will eventu­ for the future. (Walt's Note: Aluminum foil or ally get squeezed and stretched out, so it's well paper baking cups can be used to line the pan's worth replacing them occasionally. (Walt's Note: cavities, and can make picking up tiny parts The bolts can be held onto the struts or mount­ easier, as well as preventing accumulation of oil ing lugs in the same way, to avoid dropping and residue.) losing them altogether.) 3. From Mark Klein, of New Hyde Park, NY: To 2. Mark A. Sherrill, of Galt, CA, was about to isolate the rudder and tail wheel assembly, Mark throw out an old muffin (or cupcake) pan when uses aileron torque rod nylon bushings. Cut a 70 R/C REPOR T ONLINE

them in stock, they can be ordered. Gears can be replaced for a fraction of the price of a whole new servo.)

slot into the bottom of the rudder, push in the bushing, and add a drop of CA to secure it. The 6. Leo Huminick, of Weatherly, PA, wants to tail wheel tiller is inserted into the hole of the remind us that triangular gussets are frequently bushing, and then the wheel mounting assembly used to reinforce butt-joints when building. The is fastened to the bottom of the fuselage. Repairs direction of grain is very important for maxi­ to the rudder are now easier, as the tiller is not mum strength. The wood grain should always actually glued to it. Also, there is less stress run parallel to the longest side. If the grain is transmitted to the rudder servo with this setup. perpendicular to the stressed side, the gusset will likely split under stress and leave the joint 4. (No illustration) James Biza, of St. Paul, MN, unsupported. uses Zap-A-Dap-A-Goo to adhere plastic cano­ pies to his planes. He says it's a great product for 7. (No illustration) Jack DeLisle, of Saint Claire, this, but clean-up can be difficult if it wicks up MI, uses plain old cotton swabs for touching up or gets smeared onto the canopy itself. He found or painting small items when he doesn't want to that a common household product, called “Goo use a paint brush he'll have to clean afterwards. Gone”, does a great job of cleaning it off with­ If the cotton starts to come off, he throws it out any clouding, scratching, or other damage to away and gets a fresh one. He bought a 250 the plastic. Just scrape off the bulk of the adhe­ count box about five years ago, and still has sive with your fingernail, and then gently rub the about half of them left. (Walt's Note: I suggest residue with “Goo Gone.” using good quality swabs, such as "Q-Tips" for this. The cotton ends come off cheaper swabs LIFT CONTACT RETAINER TAB more easily.) (Editor’s Note: I once used cotton TO REMOVE THE EXTRA WIRE IF DESIRED. \ swaps this way, but now Harbor Freight stores sell20-pc packages of cheap, artist’s brushes for 99φ. They cost more than cotton swabs, of course, but they work better and are still too cheap to worry about cleaning.) 5. From Jim Crawford, of Merced, CA: If you have a bad servo that is not feasible to repair, at 8. Here's one from me: When scratch-building least save the connector and lead. It can be used small planes using a single servo to drive two to adapt a different servo to fit your receiver, or strip ailerons, the control arms usually stick use it on batteries that come without connectors. straight out from the center of the wing. Com­ Since most batteries use only two wires, the mercial aileron control linkage is available in third wire can be removed from the connector. various sizes, and does a fine job. It's easy to (Walt's Note: If the gears are the only damaged build your own, though. Most small to medium parts, replacement gears are often available from size models use 0.062" to 0.093" diameter wire. well-stocked hobby shops. If they don't have Smaller models may use even smaller wire. Use July 2009 71

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about 3/16" to 1/2" of one end. Drill a 1/16" hole in the center of the flattened area if standard clevises will be used. If another method of attachment is used, drill to match so there is minimal play. Sloppy linkage will promote aileron flutter. Cut the tubing to the desired length, and use JB Weld metal epoxy or solder to hold it on the wire. 9. (No illustration) Here's one from Suzi, my wife! It's easy to forget these hints and ideas as the correct size aluminum (or brass) tubing for we get older. This column or any other can be bearings, and bend the wire to the desired size printed, hole-punched, and kept in a loose-leaf and shapes. Be sure to make left and right-hand binder for future reference. If you don't want to torque rods. The linkage attachment arms can be use expensive color ink, use the correct printer made from the same size tubing. If larger diame­ command to print them in black ink only. ter arms are desired, use the next larger size -Walt Wilson tubing slipped over the smaller size. Mash flat (see addresses at top)