Fine �\\brking'___ _------______Ma Y/JUne 1981
Wo oden Jointer How to build this essential machine
by Galen Wine hip
even years ago I walked into a local arrived at the design fo r the jointer cast-iron counterparts, my wooden hardware store to buy an odd assort shown here. It requires no exotic, hard jointer incorporates four sets of inclined mentS of stuff. "What are you going to to-find hardware or materials, and it ways or wedge-shaped bearing blocks. make?" asked the quizzical gentleman doesn't call for any tricky methods of As shown below, these provide the waiting on me. "A wooden jointer, " I construction. Its performance rivals that means fo r raising and lowering the replied, trying to sound confident. He of an industrially produced machine, tables. The wedges on the bottom of was both astonished and skeptical, and though its price (about $350) is consid each table (elevation blocks) ride up did his best to persuade me to buy the erably less, and its fe el and appearance and down on the stationary ways (bear jointer on display in the store. Despite are friendlier. I'v e been using this ing blocks) attached to the frame assem his warning that a jointer is a precision jointer fo r about 18 months, taking it bly. This system is especially suitable for tool and not the kind of thing you just from one job site to another, and 1'm a wooden jointer because it supports throw together in your shop, I bought very happy with its design and with the each bed at fo ur points, rwo at each the items on my list and thus embarked results it produces. end, eliminating the possibility of on my first tool-building venture. Like certain of its ind ustrial-duty, drooping tables and providing very That first jointer worked, bu t it left up� --<--up several things to be desired. So I deter -down Outfeed table, Infeed table� down-+ mined to make a jointer that would per form as well as a commercial model. I subsequently tested five designs, each Bearing blocks-0 Elevation blocks one simpler, more reliable and more (stationary) precise than the one before. Finally, I
44 Costing about $1, 000 less than comparable factory-built machines, this wooden-bed jointer can be bui lt with ordi nary shop tool s. It jo ints a square, straight edge on boards fo r gluing up , and can face -joint boards up to 6 in. wide. The view fr om the motor side, below, with the bed turned on ed ge, reveals the inclined ways that allo w both infeed and outfe ed tables to be adjusted.
stable working surfaces. I'v e jointed a machinery distributor. The cutterhead facing. The gluelines need time to cure lot of long, heavy stock with this shaft runs in two self -aligning, ball thoroughly, and the laminated slabs machine, and found it can easily cut a bearing pillow blocks, which you can need time to stabilize. true edge on an 8/4 board, 8 ft. long get at any well-stocked industrial The tables shown here are propor and 10 in. wide. supply or farm-supply store. tioned to my own preferences: the in The cutterhead is the heart of the ma For driving the cutterhead, use a 1-HP feed table is 10 in. longer than the out chine, so you should get one that is or 1Yz-HP, 3,600-RPM motor. Select a feed because I find this easier fo r joint well-balanced and perfectly round pair of pulleys that will turn the cutter ing long, heavy stock. But you can make (square cutterheads are dangerous) and head about 5,000 RPM (about 4,000 sur them of equal length, as is common that has been turned and milled from a face feet per minute) . practice, or you can experiment to learn single piece of bar stock. It should have The infeed and outf eed tables are what suits you best. The same holds a cutting arc of about 3 in. and a hefty laminated from quartersawn, face true for the dimensions of the fe nce. shaft, % in. in diameter. Mine was glued boards. I used o/4 -in. beech, but Yo u can make one fence for the kind of turned and milled by a machinist friend, maple or another hard, heavy wood work you do most, or you can make sev who got the shaft too small fo r my lik would do. Since the finished tables are eral of different sizes fo r different jobs. ing. I'll soon make a new one with a 3 in. thick, you should rip the laminae Since you're making your own, you %-in. shaft , which will minimize vi to a rough width of around 3% in. to aren't limited by what some manufac bration and increase durability. Yo u can allow fo r a preliminary and a final sur turer decides is the average size. have a machinist do this work for you as facing of both sides. Use yellow (ali The jointer frame consists of two sides I did , or you can buy a cutterhead as a phatic resin) glue, and allow the tables and three sets of blocks-two pairs of replacement part from a woodworking- to sit fo r several weeks before initial surr bearing blocks and a pair of clamping
Photos. except where nOted: Pett Krumhardt 45 Jointer tables and frame assembly % 4 Outfeed table, x bolt epoxied 3 x 6 x 26 into guard Cutterhead guard Elevation block "-11_ Chip Guard mount --- �deflector 1'/. Infeed table,� 3x6x33
• • Fence support • top '/. • x 3 % hanger4 bolt '/·X2 n- .carriage x lag bolt I bolt in counterbore for attaching '/. box to frame x 2Y, dowelDetermine '� d by � adding '/,6 indis?arre
Ta ble/frame assembly in elevation % '/. 7 x carriage bolt x 6 hanger bolt Y4-in. plywood chip deflector I Elevation bloc7k. ,- Clamping block
% ·Cutterhead not shown. T-nut epoxied into wing
Tzlting fe nce assembly consists ofa sliding table, a slzding tzlt base, a tzlt bracket and a fence, which can vary in size to suit the needs of the operator. Removing the fence- support top gives access to V-belt and arbor pulley.
46 blocks. The top edges of the bearing blocks are beveled at 30·, and the clamping blocks are slotted for clamp ing bolts. The clamping blocks, though not beveled, are set at a 30· angle to the top of the frame. The drawing (facing page) dimensions and locates these parts. Make sure when cutting duplicate parts that their dimensions and angles are precisely the same. This can be done by ripping and beveling a single board and then crosscutting identical parts to finished length. All the blocks must be oriented at a true 90· to the frame sides, and the clamping blocks ought to be positioned as close as possible to the center bearing blocks. The outer bear ing blocks should be flush with the ends of the frame sides. To add strength and to help position the parts during clamping, I cut narrow tenons on the bearing blocks and dadoes in the frame sides to house them. But you need not go to this trouble to get similar results-just clamp the frame Particleboard base contains separate compartments fo r the motor andfo r chips and shavings. sides together with the bearing and Door to shavings bin slides up and do wn in ra bbeted cleats. Opening in side under the infeed clamping blocks between, and then tap table gives quick access to the wing nut that must be loosenedfo r making changes in depth of cut. The T configuration of the base concentrates the machine 's wei ght on three points, them into their exact positions with a eliminating the need to le vel it to the floor. mallet. This done, tighten the clamps, and bore for dowels through the frame Jointer base 16 x16x22 sides into the- blocks as shown in the Motor enclosure. drawing (% in. dia. holes fo r the bear }'.X }'. ing blocks, %-in. dia. holes for the clamping blocks). The dowels will let cleat you place the parts accurately when glu 9Y, x 48 x 22 --'!oJ ing up and will reinforce the frame as Base cabinet sembly. The �4-in. dowels are slotted and wedged. Since you're gluing end grain to long grain, epoxy is best; size the end grain before gluing and clamp ing. When the glue has set, sand the dowels flush with the frame sides. The base, which you'll probably want �-t-_-+_ to make while your table laminations Access area to infeed table are aging, is of %-in. high-density par clamping nut ticleboard. Plywood will suffice, but it's Shavings more expensive and not as rigid or removal door heavy. With a plan view that resembles Relief cut a T, the stand is constructed using cor ner cleats, screws and yellow glue. This type of base has several advantages. One jointer wider than the one you're mak both tables through the thickness is that the motor is enc losed in a ing. If you can't find a friend who'll let planer for several light passes to bring separate compartment, protected from you use his, or a school shop where you them within lja in. of their fi nished dust and shavings. Another is that the can do this work, you'll probably have thickness. Again, be careful to set the shavings, being contained in a single to pay to have it done at a local millwork planer's bedrolls properly to prevent bin, are easily removed . A third ad or cabinet shop. You could even do it snipe on the final pass. vantage of the T configuration is that with hand planes, winding sticks and a Now place both tables upside down the weight of the machine and the base straightedge, but you must be very pa on a perfectly flat surface, butt them rests on the three extreme points, and tient to get the results required. end to end, and separate them about thus leveling is never required. Begin by jointing one face of each 2 in. Get two small boards, each about Surfacing the tables is easy if ,you table, being careful to take light cuts 9 in. long, 2 in. wide and exactly % in. have access to a thickness planer and a and to avoid sniping the ends. Then run thick, and put one across the outer edge
47 of each table. Place the frame assembly with an accurate straightedge. If they four holes to be drilled through the upside down on the rwo boards, which are truly straight and in the same plane, shims and frame sides. The diameter of will hold the frame % in. above the bot you can take your jointer back to your the holes should be slightly larger than toms of the tables. Position the frame shop and continue construction. If not, the %-in. carriage bolts that will hold and tables relative to one another, and find the source of the error (it could be the pillow blocks in place. These bolts check the spacing between the two in the iron machine), eliminate it and may have to be retightened from time tables to make sure there's room fo r the take another light cut the fu ll length of to time, because seasonal shrinkage rotating cutterhead. Apply some yellow both beds. Remove as little stock as might loosen them. For safety, use self glue (or epoxy) to the top edges of the possible, since you may want to surface locking nuts.' elevation blocks, and slide them into the tables again in the future, should The fe nce assembly is mounted on a place berween the inclined surfaces of they warp out of true or their surfaces three-sided hardwood box. Its sides are the bearing blocks. Since the angles are get badly gouged and pitted. notched to fit over the edge of the frame complementary, the fit should be Surfacing complete, trim the tables side, and it is held in place by rwo car perfect. When installing the elevation to final width and cope an appropriately riage bolts and two lag bolts. The blocks, don 't wedge them too tightly curved area where each table will extend plywood top of the fe nce-support box under the bearing blocks; just bring the over the cutterhead. The bandsaw is should sit about Y16 in. higher than the mating surfaces into light, uniform con best for this. Don't cut the arcs so the level of the ourfeed table. This clear tact. If all eight elevation blocks are not blade exits on the top surface of the ance allows the fence table to slide free exerting equal pressure against the table, but rather so it exits on the end, ly across the jointer beds. bearing blocks, the tables will rock. about 0/1 6 in. below the top. This will The fe nce itself can be made to any Securing the tables to the frame is ac produce a little land that makes the reasonable size, though its dimensions complished by two %-in. by 6-in. ends of the tables stronger, and leaves need not change those of the sliding hanger bolts. The wood-thread ends are the straight lines across the tables intact. fence table or the hinged tilting bracket screwed at a 60· angle into the table Keep the throat opening narrow. and base. To make the table and tilting bottoms. The machine-thread ends pass The elevating mechanism fo r the in brackets, get some good 0/4 -in. birch ply through the slots in the clamping blocks feed table consists of a %-in. by 5-in. wood, and cut the three pieces to the and are retained by homemade wing bolt epoxied into a wooden crank, a sizes shown in the drawing on p. 46. nuts (optional on the outfeed table). thrust block glued to the bottom of the Then cut rwo slots in the sliding table These have wood bodies with T-nuts infeed table and a T-nut countersunk and two in the tilting bracket base. For epoxied into their centers. After the into the end bearing block. The %-in. hinging the parts together, you can cut glue holding the elevation blocks in National Coarse bolt has 16 threads per a continuous hinge into three lengths or place has thoroughly dried, remove the inch. Because the bolt moves the table use three pairs of butt hinges. You may frame assembly and bore angled pilot up and down a 30· incline, and the sine want to attach hardwood sled-type run holes in the tables for the hanger bolts of 30· equals 0.5; one revolution of the ners to the sides of the sliding table, as I and screw them into place. Long hanger crank will move the table Y3 2 in. ver have done. These will wear longer than bolts are used in stairway handrailing; if tically, a handy reference. You could plywood and will look better. Depend you can't find any, buy a couple of long mount a depth-of-cut indicator on one ing on the diameter of your arbor lag bolts, cut their heads off and die-cut of the bearing blocks. sheave, you might have to cove out an National Coarse machine threads onto To change depth of cut, back off the area on the underside of the fence sup their unthreaded shoulders. clamping nut just enough to free the port top to keep the belt from ru bbing Now you can put the tables onto the table, turn the crank to raise or lower it the wood. The fe nce table is locked in wedged ways and clamp them in place and retighten the nut. Excessive torque place by rwo wing nuts screwed onto with the wing nuts. Loosen each nut isn't necessary to hold the tables secure %-in. hanger bolts that extend through slightly and check to see that each table ly on their ways. For making the fine ad the table slots. The tilting bracket base rides freely up and down the inclines justments on the ourfeed table, I keep is secured also by wing nuts screwed on and that there is no rock or play any the nut snug and smartly strike the end to carriage bolts that extend through where. If you detect any rocking, care of the table with a wooden mallet to the fe nce table. fu lly remove a small amount of wood raise it slightly, or strike the end of the The cutterhead guard must be made from the bearing surface of the opposite frame to lower it-similar to the way of a sturdy hardwood (1 used padauk), elevation block and check again. you tune a wooden handp lane. Since Yo u may alter its standard shape as you When the tables fit and slide correct the nut stays tight, you seldom need ac please, so long as it moves easily away ly, return the whole assembly (frame cess to it. Mine doesn't even have from the fe nce when stock is pushed and tables) to your flat reference sur wooden wings attached; I use a wrench against it and so long as it covers the un face. With both tables resting flat on when it needs adjusting. used portion of the rotating knives. The this surface, tighten the clamping nuts. To install the cutterhead, first di guard has a %-in. bolt epoxied to it, and Now take the whole thing back to mension a pair of pillow-block support this bolt pivots in a hole in a mounting wherever you did your initial jointing shims, which will hold the cutterhead at block that is screwed to the sides of the and surfacing, place your jointer upside ,the proper height. Fiddle with the infeed table. A washer on the bolt be down on the borrowed jointer and sur thickness of each shim to level the cut tween the mounting block and the bo� face both tables in a single pass. Ta ke a terhead with [he tables. Screw the shims tom of the guard will ensure that the very light cut (Y32 in. or less) and check into place, replace the cutterhead and guard swings just clear of the jointer down the length of both tables at once pillow blocks and mark the centers for beds. A small tensioning spring holds
48 A lo ok underneath the infeed table shows the positions of elevation blocks, cla mping stud (hanger bolt) and thrust block, which contains eleva tion screw and crank, In the jointer frame underneath, you can see the inclined bearing blocks (ways) , the slotted cla mp ing block and the larg e wooden wing nut, The unfille d holes in the side of the frame remain fro m author's earlierexpen'ment with a dzffe re nt means ofsecun'ng the table to its ways, Th ey have nothing to do with the existing arrangement,
Left, Winchip strikes end of jointer frame with a mallet to lo wer the outfe ed table, just as in tuning a wooden hand plane, Fore and index fingers on left hand de tect the slzght movement of elevation block as it travels minutely down the ways, Above, he joints the edge of an 8-ft" 5 / 4 red oak board,
49 the guard against the fe nce and against height) determines whether the jointed machines were home-workshop quality the stock being jointed. edge will be slightly concave or slightly and were far inferior in terms of preci I finished the machine with Watco oil convex. If the table is high in relation to sion and stability to the shop-built ones and waxed the tops of the tables and the the knives, the jointed surface will be I now use. Experience has taught me sliding surfaces on the wedged ways. convex; if low, it will be concave. Also, that good work depends as much on the The base I painted grey. No fi nish, it's a good idea to check the tables occa skills of the craftsman and his sensitivity however, makes wood completely im sionally for proper alignment. Crank to factors that affect accuracy as on the pervious to moisture-I had to make the infeed table up to the exact height built-in precision of his machinery. I slight adjustments in the outfeed table of the outfeed table and then lay your have often observed students getting as its thickness changed minutely with straightedge across both beds. If there's less than satisfactory results using good the seasons. To correct any rocking or any deviation from a true plane, remedy tools simply because they believed that droop that might develop, insert paper the error with paper shims between the machines should do accurate work in shims between the bearing and eleva bearing and elevation blocks. spite of the operator. The truth is , of tion blocks. To spring-joint boards fo r Having spent quite a few years work course, that the operational skills and gluing up panels, you could shim up ing in university wood shops, I'll be first intuitive understanding of the crafts the two inner elevation blocks on the to admit that industri al-duty machine man are necessary to the precise work outfeed table so that it slopes down tools offer greater built-in precision cabinetmaking demands. 0 from the cutterhead. A couple of pieces than shop-made machines. But the dif of notebook paper would be about ferences are small, and the advantages Galen Winchip, 29, is a professional right. Remember that the orientation of of being able to build your own ma woodworker and industrial-education the outfeed table (both its angle and its chines are great. My first woodworking instructor in Ames, Iowa.
thick stock, always use a push-block. Stock shorter than 12 in. Jointer safety should not be machine-jointed, so if your finished pieces will be less than a foot long, joint the longer board before you cut Some of the nastiest woodworking accidents result from care it up. For jointing stock thinner than ¥2 in., you should make less ot improper use of the jointer. A cutterhead rotating at ' a massive push-block, like the one shown below made by 5,000 RPM looks seductively harmless; with its knives blurred John Alcock-White for jointing one face of the %-in. stock he into invisibility, all you see is a shimmering steel cylinder. Yet laminates fo r bandsaw boxes. The block should be as wide jointers regularly gobble up fingers, thumbs and sometimes and as long as the stock being jointed, and 4 in. to 6 in. thick. hands. Surgical restoration is almost impossible-repairing Used over a long time for repetitive operations, the jointer's tissue lost to a jointer is like trying to remake an original incessant drone can lull the operator into inattention. In such board from a pile of shavings. Such a nightmare can b� a semiconscious state, an accident is liable to happen. So be avoided by being careful every time you use the jointer. especially vigilant when your work is boring and perfu nctory. Before switching the machine on, make certain that the Posture and stance are also important. Learn to feed stock knives are firmly tightened in place . A loose kn ife can grab across the tables without overreaching and losing your the work or come flying out of the cutterhead at high speed. balance. Adopt a posture that will allow you to exert consis Never use a jointer unless the cutterhead guard is in place. tent downward and horizontal pressure on the stock. This not Even with the guard in place, large chips can be hurled from only contributes to safety, but also affects the results of your the machine with enough fo rce to injure eyes. So always wear work. When feeding, allow the ma chine to cut at its own your safety goggles when jointing stock. Some jointers are pace. Don't fo rce work into the cu tterhead, or try to hurry the equipped with a rabbeting table, and you must remove the board across the tables. A slow to moderate feed rate is best, guard to use this feature. But a jointer is not the best machine though pausing or creeping along during a cut can score the for rabbeting. It's better to use your table saw or spindle surface of the wood and overheat the knives. shaper or router. They do this job more safely and more effic The knives should be kept sharp, and should all be main iently. Though most jointers will cut as deeply as ¥4 in. or tained at the exact height. You can touch up the edges peri more, you shoul dn't take a cut any deeper than %I in. in a odically with the judicious use of a slipstone, but when knives single pass. Yo u risk injury from kickback when taking too are knicked or dulled beyond reason, you should have them deep a cut, and you put unnecessary strain on the motor. reground. Instruct the person doing this to remove the same When jointing the edge of a board, keep your fingers well amount of steel from each knife. Improperly ground knives away from the table surface. When face-jointing stock, even will put the cutterhead out of balance, which causes vibration and can lead to an accident, and will definitely bring about premature bearing fa ilure. When sharpening, maintain the original bevel angle. If you try to hone or grind a secondary bevel on the edges, the result will be increased noise and vibration, and decreased cutting efficiency. Constant alertness, common sense and a knowledge of cut terhead dynamics are the best safeguards against accidental injury. Used properly, a machine jointer makes a wood worker's task immeasurably lighter and introduces a high de gree of precision into the work. For more on using jointers, see FWW #19, Nov. '79, p. 93, and p. 18 of this issue. -IL.
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