strut is used to provide clearanc-e--~--'::;.:g pinnedstrutiSj be tween the back into mast jenny stay and roach stays rear edgel of the mainstrut. strut is 31/4" from mast mast is center to back raked back stay, note "0" . ; _
center of the mast is Illug- ged~ with waad--side stay thro hook to pick up headboard on . mainsail, 1/4"-0 screw i·i ~ fore stoy ~ \: stainless steel wire '. jib halyard " 1/2"0.d, jackline-- sail hooks hard wood top mast dural attach to this line. extends into 1/2" jib halyard and ·o.d. durol main the fore stay are ma It a bout 2". attached to the loop made by the o hook picks up jib headboard side stay sto through the i-'-A-_--:":(---J-_-14-,,0-, .., B- 2" K- 26" C- 2 1/2" L- 32" D- 3" M-37" E-33/4" N-40" F-41/2" - P-55" G-IO 3/4" 0-47" H-1I5/S" R-61" sail and mast dimen- L sions.
sheets, halyards and note how the side stays attach to backstay-- irish linen the chain plates--the stays I or braided nylon. meet these about 2" rearward jackllne and all of the base of the most. I I other stays are vane gear used to steer the yacht I '. stainless slee I _ ~ fishing leader. after Ihe sails are set. it mounts on the stern near the rud- der post.
rudder port is 3/16"i.d. tu 2" long and is flush with Ihe bottom plaflk and is 2" forward of the DELTA CLASS transom. EYE PLATE BICIIG YACHT HAROLD C. KETHMAN stay sai I hooks are dress hocks stainless spaced 5" apart, steel hook up hook. an .ails. most e~ralAl.' , . Plate 1 SITUATION AT THE held to deck qr mast OUTHAUL RACKS lower end of ma~,t is "FOREFOOT" OF THE With twa 1/4 -0 screws. slatted-- a 1/16 pin JIB--SHOWING THE "" is mounted through nut ARRANGEMENT OF slots are 3/8 to 1/2 apart the slot to prllvent THE JIB CLUB SWIVEL. • the mast from spiral line-wound around " ,#,,"" ""~ sliding an the the mast- holds the jack line close to the mast. ~~~\~6oJ..,j.I.\~\\ mast step. dural or brass ~~~~~\ q moat step is I 3" to 4" lono. ) side sta y mainsail attaches to a hook 1/16" mounted to bridle--note hole in mast. jib club-- maximum diameter of a wooden ~;:;: ""ClUb is 3/4".
3/8" - 0 brass screw used with ail fittings which fasten to the the lower portion of deck. th,i,s . as~embly is,,knawn as the kicking strap, the mainsail is tightened,or slack ened, by adjusting the turn buckle, this action varies the curvature, or "lift", of the sail. 3/8"-0 screws use 3/8" to 5/S" o.d, these are used to wooden dowel used to reinforce mast at base and gooseneck! tubing with a heavy wall. lighten or ad just holes (Ire larger than the SITUATION AT GOOSENECK & the stays, halyards diameter of the line and or sheets. they are KICKING STRAP--SHOWING NO SCALE are pitched inwards insure not used with wire. MOUNTING OF THE MAIN DRAWING 10 holding power. BOOM TO THE MAST.
3~ BOAT MODELS Left and Above: "Venus," the first of the Delta Class model yachts, pulls slowly away from the shoreline guided by its automatic steering mechanism-the vane gear. The large balsa feather acts as a weather vane' to hold the rudder true-to-course. Note the simple flowing lines of this double-end hull design. DELTA CLASS RACING YACHT by Harold C. Kethman
Here's a low-cost, easy-to-build model racing' yacht that any average modeller can build quiCkly without ' special tools
• If you've been looking for a compara Full-Size Plans are available from the into these pieces. Note that the inwales tively inexpensive, easy-to-build model author, as noted at the end of the article. and chine logs are inclined to one another racing yacht which retain.s the racing -make sure that this is taken into con featu.res and qualities of yachts built to BUILDING THE HULL: Start by cut sideration when angling the blocks. The the more complex M.Y.R.A.A. classes ... ting out the bulkheads, using the dimen stem block mounts on top of the batten if you want a model racing yacht which sions shown on Plate 2. Note that hal/ backbone. Tack-glue these blocks on the is interesting to sail for both the novice bulkhead outlines are shown, for the left building board. and the veteran skipper .. . your search sides only. Add the matching right sides is over! when drawing the bulkheads on 1/4" KEEL STRUT: Dra'IV a grid of 1" Even if you have to buy all the fittings, waterproof plywood. . squares as shown at the bottom of Plate 2 rather than make them yourself, the total Cut out the bulkheads with a coping and plot the curve of the strut onto a sheet cost of the necessary materials for our saw. Don't try to short-cut the building of %" dural. Cut out the strut, using a yacht-including the vane gear, mahog process by eliminating the center cut metal-cutting blade in a coping saw any, glue, etc.-should be well within outs of the bulkheads-these are neces frame. After shaping the strut, drill the your means. And no whittling is required sary so the yacht can "breathe'," permit keel bolt and lead-flow holes. Use fine -no expensive special tools-no years of ting the inside of the hull to dry if water emery cloth to polish the strut and re laborious constructiori! There's one plank seeps in. move scratches and scars. on each side and two planks on the bot The yacht must be assembled upside tom, all over a simple framework sup down on a 52" x 2" x %" clear pine build LEAD TORPEDO: This is elliptical in ported by six bulkheads, with light bat ing' board. Note that the bulkheads are shape and circular in cross-section. Make ten-backbones spliced into a central keel mounted between wooden blocks. These a mold using two blocks of 14" x 4" x 11h" mount. And the design has been tested are beveled 2° as shown in Figure A, by clear pine. Mark the outline of the tor and proven successful over a period of making the bottom 1 / 16" narrower than pedo accurately on each half of the mold more than two years! the top. as the cavities must match when the What 'are you waiting for? Mount the blocks flush with the edge mold is closed. Gouge out the cavities to This model is only one of the many de of the bulkheads and tack them to the the contour of the torpedo, making both signs possible in a new class of model bulkheads (not to the building board) sides as equal as possible, and sand racing yachts, appropriately named after with I" brads. When these assemblies them smooth. and identified by the Greek symbol Delta have been mounted on the board, they Four V4" aligning pin holes are drilled, (an equilateral triangle), used in mathe will be inclined 88° aft (to the rear) . one through each corner of the mold. A matics and physics to denote a change. Next, mark the bulkhead locations on cut-out is required to seat the blocks Rating restrictions have been kept to an the building board, following the dimen~ around the strut. It is also necessary to absolute minimum-the major restriction sions shown in the half top-view on Plate cut out a pour hole and a series of small is ' on sail area, which is limited to 600 2. Then; drill holes in the board ' so that diameter vent holes so that the lead can square inches. The Delta Class was wood screws can secure the mounting be poured into the mold. evolved by Jim Dempsey, Bob Leopold, blocks to the board from below. (After Insert and center the keel strut and put and the writer-all members of the Long . the hull has been fully planked, the four aligning rods into the holes in the Island (N.Y.) Model Yacht Club. screws are removed) . mold to keep the unit from shifting. Then, Carefully check the Bill of Materials clamp the unit together with a large "C" and gather together the necessary ma STEM & TRANSOM BLOCKS: These clamp or in a vise. hogany, plywood and other lumber before are cut from pine or mahogany-the di Approximately eight pounds of lead are trying to begin construction. If you have mensions are shown on Plate 2 (inside 2A required to make the six pound torpedo. ' difficulty securing any of the materials and 3F) . Bevel all edges correctly as the Melt it in a steel or cast iron pot such as locally, check the sources of supply listed. planking and batten backbones must fair those used by plumbers. These have a
BOAT MODELS 35 inwale / ioIIl:------
ALL MATERIAL IS HARDWOOD OR MARINE PLYWOOD. DON'T USE BALSA!
side view of .: : this hu II is not ·.·········.... . shown as it is ".' . not necessary =UI "" "" to the COll- 1 .g.;;:: struction. ,.,'"
this is a NO s..c.A1.E d r ow ing -- follow the dimensions!
rudder post (2" 1/4"above top of rudder) ~-T--T-~r-~ BALANCED RUDDER Made from 24ST Dural eheet. DELTA CLASS
DCIIG YACIT-U) LENGTH OVERALL _ 50 DESIGN BY: HAROLD C. KETHMAN ~ . LOAD WATER LENGTH Upper section of keel U, BEAM.~ ______strut Is bolted between rt).;;:: DRAFT~ ______~ two keel blocks and Is 10 sealed with white lead. - DISPLACEMENT_----=!~"OIDl11 "· ":">" "" SAIL AREA ______fOAJUIC~I"l """""""""
Lead torpedo--IO" long, I 3/4" In diameter, 6lbs. in weight.
36 BOAT MODELS Motorize Your Hobby Kits With Low-Cost Reliable HI·DRIVE MINIATURE BATTERY-POWERED ELECTRIC MOTORS ACTUAL SIZE "ere IS tne finest miniature motor on the market. E:xcep tionally low drain allures longest battery life and economy of operation. If your deal.r cannot supply, he will gladly OLD TIME CARS order from his distributor.
SP IC IF ICATION 5 51%1-11(,* hleh-l%" 1!rId.-Hi" .... - WIIGHT .... 1.94 02; 1 ...., - 2000 to lOJlOO .M. ot 1VJ to 6 ~ D.C. /$ ...... ~2OOO , MODERN MOTOR CARS RAY-O-VAC COMPANY (Special Products Division) MADISON, WISCONSIN pouring spout bent into the rim and are screws are used to fasten them in place. safe to work with. Scale or sludge that Small copper or brass lills (pins) may be forms on top of the lead should be substituted but screws are preferred. skimmed off. Wherever screws are used, the wood Classified - Boats Use this directory for prompt response. Rate 15c per Pour the metal cautiously. Work slowly will require predrilling to avoid splitting. word. (Minimum 20 words.) Cash WITH ORDER. and stop periodically to prevent the gases' Use a drill of a smaller diameter than the 5% discount for three or more insertions to direct in the mold from spewing the lead out. screws so they retain their hGlding power. advertiser. Make remittance payable to FLYING MODELS, Boat Classified Dept., 215 Fourth Ave., All portions of your body should be cov Do not bevel the chine logs until the New York 3, N. Y. ered with protective clothes and your side planks have been fastened in place. .eyes and face must be shielded at all FOR SALE times. Note: Do not pour lead in your PLANKING: Before starting, sand the STEAM ENGINES, BOILERS for model power home, or over fioors that can burn! sides of the hull smooth so that the planks boat s; gasoline blowlamps ; castings ; Blue Prints ; Pour until the mold is filled. A cooling will contact the framework at all points. Boat Fittings. Catalog 26c. Anton Bohabo7, 2297 time of 20 minutes is required before Use a coarse grade of garnet paper Price St., Rahwa7 5, New Jerae7. opening the mold. Water quenching is wrapped around a wooden block which is I---P-O-W-ER-ED-S-P-E-E-D-M-O-D-El-S-.'- advisable if you have any doubt. Remove large enough to bridge across the inwale the torpedo and file it into shape. The • and chine log, so that they can be used as slag formed by the pouring spout and guides. Speed Liner vent h6les should be cut off, Two 55" long 3%" wide planks of %" mahogany sheet are required. The top MOUNTING THE KEEL: The keel edge on each side plank is planed straight strut is sandwiched between two mount a nd square so' that the deck can be fitted ing blocks as shown in Plate 2 (inside to it. 1A). Note that they are beveled to the Temporarily mount the planks so that angle' of the bulkheads. The ends are the squared edge is fiush with the top of notched to receive the batten backbones. the inwale. Draw a pencil along the edge Apply a coat of varnish to the inner sur of the framework to trace the outline, faces of the blocks to seal the grain. Use including the stem and transom. Then saw Oelu •• Runabout white lead as a sealer when bolting the the sides 'with a coping saw to within keel strut between the blocks. 1/16" to 1/ 32" of the finished size. This assembly is fastened between 1/4" No. 0 fiat-head screws are used to bulkheads 1A and IF as shown in Plate fasten the side planks to the framework. Now-a choice of t hree scale models of 2 (inside IF), with eight 1" No. 6 brass Weldwood glue is used throughout the as popular power boats in easy-to-build top round-head wood screws, and is secured sembly. The screws fasten to the inwales quality kit form: the new CHACK Elt with Weldwood glue. During this opera and chine logs-not to the edges of the BOX, a 15" model with a ll die-cut mahog tion, bulkheads 1A and IF can be removed bulkheads. Approximately two screws are any and balsa parts, separate die-cut from the building board temporarily. The used between bulkheads. Four or five planking fOI' decking, plastic ' seat and alignment of this unit is critical. Check screws in the stem and transom blocks steering wheel, and step-by-step ins tl'Uc to see that the strut lines up with the will be sufficient. tions, for $2.95 .. . the DE LU XE R UN centerline of each bulkhead. It takes about 24 hours for the glue to ABOUT, a 21'; model with completely dry properly. When it has, sand the bot preformed hull, bu il ~- up fl oor rack,' etc. BATTEN BACKBONES: Both back tom edges of the side planks and the chine at $3.95 . . . and the SPEEDLINER bones (fore and aft) are made from %" x logs fiush with the rest of the framework. RUN ABOUT, another prefabl'icated, 114" mahogany and beveled to conform Use coarse garnet paper on a block, as top-quality kit, for $1.95. All can be pow with the bottom angle. Note that the end before. The bottom planks :;hould touch ered by gas 01' electric engines. Get you I'S of each backbone is slitted to fit around every point of the framework. t oday! the kee~ strut into the cutout provided Two 5" wide 55" long pieces of %" ma Crackerbax kit, compl.t..... $2.95 in the keel blocks. Each is fastened in hogany sheet are used to make the bot DeLuxe Runabout kit, complete.. $3.95 place with Weldwood glue and %" No. 2 tom. Each of the two sheets is held in Sp.edlifter Runabout kit, complete $1.9S fiat-head brass wood screws.- counter place to trace the outline. Include an in sunk. Use a block plane for final trim let in both planks so that they fit around ming at the stem and transom. the keel strut. Coping-saw the planks to shape. They should fit fiush over the edges CHINES AND INWALES: 1/4" square of the topside planks and may be over pine strips are used for the chine logs and lapped or butt-jointed at the centerline inwales. Each should be 55'; long. Note in of the backbones, as you desire. Holes are . 'I'. ~Q'R .~~~ Plate 2 (inside 2A and 3F) how they are drilled next so that the planks can be formerly McManus Novelty Co. scarf-jointed into the stem and transom screwed to the chine logs and batten blocks. Weldwood glue and %" No. 0 backbones. Then mount them in place. 754 MAIN STREET FITCHBURG, MASS. BOAT MODELS 37 Allow the glue to dry and sand the rudder post. It should extend 21/." above surplus edge flush with the sides. Then, the outline of the rudder proper. This detach the hull from the building board provides enough length above the rudder by removing the screws which hold the port to mount the tiller bar. mounting blocks. Carefully pry the tran som and stem blocks loose. Once the hull DECK FI1TINGS AND RIGGING: is off the board, it is easy to detach the Plate 1 shows all of the rigging and fit mounting blocks that held the bulkheads tings which you will require. These in place. should -be brass so that they won't rust. Sand the hull smooth using coarse pa The.y can be homemade or purchased per and working down to a medium from m odel yacht supply houses. In addi grade. Final sanding is left until the deck tion to these, you will need a drain plug. h as been attached. Trim all excess plank This mounts through the deck and opens ing from the transom and ste.m blocks. up so that the inside of the hull can be Add a ¥a" cap strip over the forward ;lired out. It should be left open when edge of the stem. storing the yacht. DECKING: A kingplank is inserted be 8OT[DING BOARD: fore mounting the deck. This is a %" w ide ASSEMBLE TWO PIECES OF 3/(' PINE INTO A "T" AS IS SHOWN BELOW. MARK strip of !fa" mahogany sheet. It should be TH E POSITIONS OF THE glued and m ounted in place using Weld wood and small 1/4" No. 0 screws. The rudder port-a 2%" length of brass '~'~ tubing with a 3/16" inside diameter-is m ounted at this time, as sh own on Plate 1. -.-- The 3/ 16" rudder post (shaft) should turn The Cameron .09 Mori". Engine was c:tev.loped np«lally tOt poweri ng model boot.. It i, available in 0 two-~ model In addition to the con freely inside of this tube. Snug-fittmg ~f.onal a.ing le-speed model. The tNO -speed (double let mocWl g i..... the holes are d r illed 2" from the outer end of THE BULKHEADS UM' of radio control mocMl. the added a dvantage of being obi. to chongie ARE MOUNTED ,of t~ .ng i~ while ,he bool il .in operation. The r.guiar . i ng~ . Ueed the transom up through the' backbone BETWEEN TWO . the ';~%,! i~~, f:'~Jli; ::~~;., radio control boots where tw= BLOCKS, SUCH AS The Cameron .09 Special Morine Engine can be uMd in ~ ri ng model and kingplank to hold the rudder port. bool~ of almo.' any a.iu . In tatting du,ina .its development, 0 row boor THOSE SHOWN AT co'l"f1ng four people WOI a ctually lowed by a SInOIl radio controlled boot When installed, the rudder port should be LEFT, TO OBTA.IN p~t9d by a Ca"...fon .09 Morine El'IQ ine. flush with the outside of the underbody PROPER ALIGNMENT. !io!: Ihr~h~:. .~ ;~cZj~O~ .~:· 'h:c!~~ro-:~, ·~:di!i~~:n ~:II ~': : ;SOl THE BLOCKS ARE Ina,. all po&Slb."ty of uneven e.ponlion or thennal d istortion during oper. and extend above the kingplank. BEVELED 2' ·TO otion. It . I, a lopped.,J'ilron type engine havlr.g one-holf Inch bore and White lead is used to seal the tubing in KEEP THE LEAD one-holf II'lCh .. rob. 0 i, precision built, using the belt materlol, fhrOUVh out. All ,working port. or. heal Irlt