how 2 build- a tractor

7/29/2019 How 2 Build- a tractor

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Includes

Completedetails on asmall farmtractor whichmay be builtfrom old auto-mobile partsat small cost,and also plansfor a gardentractor pow-

ered with asingle-cylindermotorcycleengine

How to Build Your Own

FARM orGARDEN

TRACTOR

Second Printing 1941

POPULAR MECHANICSCOMPANY

1939

Printed In u. s. A.

No. 8

POPULAR MECHANICS PRESS

200 EAST ONTARIO STREET * CHICAGO


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PART I

Frame, Motor, Steering Gearand Driving Mechanism

HERE is power and plenty of it for truckgardeners or owners of small farms whowant a dependable tractor at low cost. Itshigh wheels and wide tread make thistractor ideal for modern row-crop tillage.Under average soil conditions, it will han-dle a two-bottom 12-in. plow, a 6 or 7-ft.tandem disk harrow, and with a little al-tering, some two-row cultivators can be

adapted to use with it. In some cases,wheel weights will add considerably to thetractive effort under heavy pulls. Anyonecan build the tractor as it consists of old

By H. SUDDABY

car and truck parts so ingeniously selectedthat the assembling can be done withwrenches, a hack saw and a little welding,the latter being done for a few dollars byyour local machine shop.

Begin construction with the steering as-sembly, which is detailed in Figs. 1 to 5.For this you will need one Chevrolet steer-ing column complete, one differential hous-ing, two axles, two front spindles completewith wheels, and one model-T Ford truckdrive-shaft housing. First cut off one endof the differential housing at the springsaddle 4 in. from the brake assembly. Re-move the rivets that hold the brake flange.Next cut off the end of the driveshafthousing 4 1/2 in. from the universalcasting, removing enough from the other

end of the housing to make it 37 1/2 in.long. Now weld the short piece ofdifferential housing to the driveshafthousing as in Fig. 3. No-tice that therear-axle bearing is used to


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support the front end. It is a good idea to

examine this bearing closely for wear. Ifundue wear shows, it will pay to replace it.The dust plate and grease container arecut in half so that they can be bolted to theaxle after it has been inserted.

Then assemble the Chevrolet axles insidethe housing, using one full length and a12-in. length of the other. To save ma-chining the shafts, you can connect theirsplined ends together with the rear half ofa Chevrolet truck universal joint as inFig. 2. The shoulder or flange is sawed offto leave a splined sleeve, which ties themtogether without play. Mount the steeringcolumn on top of the assembly as in Fig. 1,

and weld the end of the shaft thatprojects from the gear housing tothe axle end. You will have todrill and tap the upper end of thedrive-shaft housing for a capscrew to keep the column inposition. The steering-wheel shaft

will have to


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hole. Then when youbolt the assembly to-gether, there will be

no tendency of the frame to rack laterallydue to the tight fit of the bolts. A lengthof heavy angle steel bolted across the un-derside of the frame members will supportthe front end of the motor, while steel an-gles located at the rear of the frame asindicated will tie it at these points.

Now we are ready for the power plant,which is a model-A Ford motor completewith starter, generator, transmission, bat-tery and ignition system. As this is theheart of the tractor, it must be in good con-dition. If the motor has seen considerableservice, it should be reconditioned com-pletely and any worn parts replaced. Thesame goes for the transmission. Removethe cover, wash out all old grease withgasoline and inspect the gears and bear-ings for excessive wear. If some are wornbadly, replacement at this time may avoidbreakdowns later. Assemble the trans-mission and fill it with fresh lubricant.

Now mount the motor assembly tempora-rily in position in the frame. Then get afour-speed Chevrolet truck transmissionand a model-A Ford truck differential

assembly to complete the driving mech-anism. Clean them thoroughly and inspectfor wear, replacing any parts that seem tobe worn badly. If this is not done, addi-tional wear will be rapid due to continu-ous strain on these parts when the tractoris pulling a load. To connect the trans-mission and differential, carefully squarethe stub shaft of the latter with a file totake the square opening of a connectormade by bolting the rear halves of two

Chevrolet-truck universal joints togetheras in Fig. 8. Then cut off the model-AFord drive-shaft tube that came with the

with a welding torch to allow the steeringcolumn to be inserted and welded as shownin Fig. 3. These members must be welded5 in. apart to allow them to be slipped overthe ends of the frame members and fas-tened with 5/8-in. bolts, the top front mem-ber being located 24 in. from the top of thedrive shaft. As the front of the frame issubjected to rather severe twisting strains,it is best to drill the holes with a 5/8-in.drill bit, using each cross member as a

jig so that the holes register perfectly. Ap-plying lard oil while drilling will help as-sure a clean, true


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FASTENING SPINDLE ASSEMBLIES TO TAPEREDEND OF AXLE SHAFT TILTS WHEELS AT JUST THERIGHT ANGLE FOR EASY STEERING

end to permit them tobe bolted to the motor.However, it is a good

plan not todrill these holes until the frame is assem-bled with the two front members and therear member bolted in place as describedlater on. It will help greatly when you getthe frame assembled to support it at aconvenient working height. Then whenyou have the rear transmission and rearend ready, these parts can be bolted andblocked temporarily in place and the mo-tor set in position for alining as you see itin Fig. 9. To make the assembly line upproperly it may be necessary to shift themotor slightly. This would mean that ifholes were already drilled you might have

some difficulty relocating them in the re-quired position. The two cross membersthat support the front-end assembly have3-in. holes drilled or burned in the center

be cut in the center and a 4-ft. length of3/4-in. pipe slipped over the ends andwelded to lengthen the shaft so that it willreach back to the operator's seat. Nextcomes the wheel spindles, which arebolted and welded to the tapered lowerend of the steering assembly after cuttingthe bosses off the spindles as shown inFig. 3. Care must be taken with thisassembly to make sure that bothspindles are tilted to the same angle asindicated. In the vertical plane thespindles should aline exactly, otherwise,the front wheels would toe in or out,making the tractor difficult to steer.

Now you are ready for the frame. Theside members are made from channel steelas in Fig. 6. They are drill ed asind ica ted 37 1/2 in. from the front


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transmission, holding it rigidly to theframe. Several short bolts must be screwedinto the holes in the front end of thistransmission, that formerly held the clutchhousing to the transmission, to prevent thegear oil from leaking out. However, twoof the bolts are used to hold the supportpreviously mentioned. Next, the front mo-tor support may have to be bent up ordown to aline the transmissions with oneanother. If the two are in alinement, thejack shaft at the rear end of the Chevrolettransmission can be turned freely with thehand if both transmissions are in neutral.After this work has been done, bolt therear end assembly to the Chevrolet trans-mission and fasten the axle housing rigidlyto the frame with heavy U-bolts. Be sure,before you draw up the bolts between thetransmission and rear end, that meetingsurfaces are entirely free from hardenedgrease or accumulations of dirt. Use lock-

washers under all nuts and cap screws anddraw them up evenly to avoid strippingthreads. See that the driving assembly isnot thrown out of alinement in doing this.

It is a good idea to tack-weld the U-boltsto the axle housing after perfect alinementhas been assured. You are now ready forthe wheels, seat and drawbar.

Lightweight Metal Doubletree Can Be Assembled EasilyThe main leaf of an old car spring is used

for the back of this metal doubletree andis braced with a piece of flat iron weldedbetween the spring eyes. These form nat-ural connections for the singletrees, and

squares of heavy iron welded to the topand bottom of the doubletree take thetongue pin.


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rear end of the frame. A connector to fastenthe stub shafts of the two transmissionstogether and complete the driving mech-anism is shown in the circular detail of Fig.9. This consists of a Chevrolet clutch hub,with the clutch disk removed, welded to thefront half of a model-A Ford universal joint,

which has been sawed off as indicated by thedotted lines. This gives you a strongconnector that will slip over the splined endsof the two transmission shafts of differentdiameters without ex-pensive machining inhaving a sleeve made for this purpose.

Now you are ready to aline the motor,transmissions and differential and bolt themin their respective positions in the frame.This must be done perfectly, other-wise thebearings will wear rapidly. The motor has tobe tilted down in the rear so that thetransmissions and drive shaft are in a

straight line with one another. Afterall shafts have been lined up, anangle steel support should be bent

and bolted in place onthe front end of theChevrolet

truck differential 8 in. from the flange at the rear end and weld therear half of a Chevrolet universal-joint housing to the severed end asin Fig. 7, first cutting off the rear end of the universal housing as

indicated in Fig. 8. This allows you to bolt the transmission anddifferential rigidly together as shown in Figs. 9 and 10. Now set thisassembly temporarily under the

FORD' MODEL- AMOTOR COMPLETEWITH TRANSMISSION,

STARTER ANDGENERATOR

MOTOR SUPPORTSTEEL ANGLE


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PART II

Assembling rear wheels, installing radiator, batteryand ignition system, drawbar, driver's seat, etc.

By HAROLD SUDDABY

A FTER finishing the tractor frame andinstalling the motor, driving mechanismand rear end, you are ready for thewheels. Each rear wheel consists of awagon-wheel tire 40 in. in diameter and3 in. wide, twelve angle-iron spokes 16 in.long, and the disk wheel that came withthe truck rear end as shown in Fig. 12.First cut off the rim of the truck wheel asin Fig. 13 and place it level on a floor. Nextplace the wagon tire over the wheel andsupport it 6 in. above the wheel. Space thespokes equi-distant around the wheel andtire and weld them in place as in Fig. 11.If desired, you can hot-rivet the spokes tothe wheel, and if possible electric weldthem to the tire as this gives a strongerjoint than a welding torch. Now drill thetire and bolt angle-iron or steel lugs to it6 in. apart. If the work has been done

carefully, you now have a wheel with a 6-in. dish that is strong enough to withstandthe pulling strain of the tractor. If youcare to go to the added expense you canuse rubber tires instead of the steel rims.If this is done, cut the spokes to suit therims and assemble the wheel in the sameway.

Next comes the fuel tank. As the model-A motor has an updraft carburetor with agravity feed, the tank must be elevatedabove the motor in a manner similar tothat shown in Figs. 15 and 16. Install theradiator so that you can have the regularhose connections, using the original spring-

type mounting as in Fig. 14. Install theoriginal model-A ignition system completewith generator and starter.. Make up a


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wood instrument panel for the ammeterand switch and mount it at the rear of thegas tank. Bolt the coil to the front end ofthe gas-tank support and run a wire fromone terminal of the coil to the ignition

switch. Connect the other terminal of thecoil with the starter button. The wire fromthe generator to the starter completes theprimary circuit. A wire from the center ofthe coil to the distributor cap completesthe high-tension circuit. The throttle andchoke are operated with dash-type con-trols, and should be placed close at hand.In fact, all of the controls are on the right-hand side of the steering-post support.

Any good 6-volt storage battery will dofor the tractor, and you can use the orig-inal Ford battery cables, grounding theshort one to the tractor frame and runningthe longer one to the starter terminal. As

the tractor is operated under dusty con-ditions, it is a good idea to solder a heavycopper wire to the motor and to the frame

battery when the tractor is in the field.The starter switch is attached to the start-er housing so you will have to run a smalliron rod from it to within easy reach of theseat so that the motor can be started fromthis point.

The seat should be mounted so that itwill support several times the normalweight of the driver. This is important asserious accidents can result if the seatbreaks while the tractor is pulling an im-plement such as a disk harrow. Fig. 17shows a way of mounting an ordinary im-plement seat to give ample strength. Aspring back like that shown adds bothcomfort and safety for it will help to pre-vent the driver being thrown from the seatwhen running over rough ground. Bolt theseat to the frame a suitable distance fromthe steering wheel as in Fig. 17, using lock

washers under the nuts. It is a good idea touse lock washers under all nuts through-out the tractor as the shocks received in

to assure a good electrical contact betweenthem, as the motor and frame are used asone side of the electrical circuit. Connectthe negative or minus post of the batteryto the short cable which is grounded to theframe. If the ammeter shows "discharge"when the motor is running, reverse theconnections at the battery posts. Also ad-just the charging rate to just a few amps.Check the battery frequently to avoidovercharging. This is likely to happen un-less the charging rate is controlled care-fully because there is little drain on the


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this type of work have a tendency toloosen them. The method of at-taching a simple drawbar is shown inFig. 17.

The rest of the job consists offinishing touches. You may ques-tionthe fact that standard Chev-roletdisk wheels are used on the frontwithout additional rims but this wasfound entirely satisfac-tory in actualuse. You can add individual brakeson each rear wheel which will helpin turning while pulling heavy loads.This can be accomplished by boltingtwo 1-in. flat-iron handles on eachside of the frame slightly ahead of the

seat, using 1/4-in. rods to connect them tothe brake arms. A coat of goodimplement paint will improve theappearance of the finished machine. Thefirst time you run the tractor it may be alittle puzzling because of the two gearshift-levers. The first thing to do is toplace both of them in low gear and usethe Ford transmission

for higher speed if necessary. When you

have completed this machine, you will findthat it has plenty of power and that itsturning ability and usefulness are far su-perior to most tractors built from car parts.

how 2 build- a tractor

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