cars,

Chassis for aSuburba-car

The Suburba-car chassis was designed under the auspices of POPU-LAR MECHANICS by the students at the Illinois Institute of Technol-ogy. It was designed to be the "missing link in transportation,"—atruly compact car that one or two people might use for suburbanshopping or commuting. Readers were asked to submit body designsto fit the chassis, and the design of Norman K. Niemi was judged asthe best of the large number submitted. His design is really a tripledesign—the three drawings at the top of the facing page—demon-strating the versatility of the chassis. It could be a practical littlepick-up for light hauling, a nifty little runabout for quick shoppingtrips, or the smartest, tiniest station wagon ever seen. Try buildingthe chassis yourself, then designing your own body for it.

BUILDING THE CHASSIS frame is a pure andsimple welding job, only a few of the parts beinga little tricky to fit and hold in place while you'repouring rod. In some instances dimensions ofparts give only the rough sizes and angles as somefiling and hand fitting is essential to get thingssquare with the world before welding. Also,there's some latitude for exercise of your owningenuity in making and assembling some of theparts. An example is the steering-gear assembly.The original is detailed, and testing has provedit to be serviceable and entirely safe for averageuse, but, of course, it can be bushed and other-wise elaborated if desired. Also, the inclinationof the steering column and placement of thetilting seats have been purposely left to the de-sires of the individual builder.

Before welding the four members of the basicframe make sure that the assembly is square atthe corners and true along the length. Keep inmind that in the assembly the rectangular frameis supported at an angle with the horizontal, itsinclination being forward, but that the "bridge"

supporting the rear deck rides level. Elevation ofthe deck framing is determined by the fit andslant of the four supporting members, or legs, asin the exploded view. Once the basic rectangularframe has been assembled and the additionalparts No. 30, 31, 32 and 33 have been weldedin place, take special note of the placement ofthe remaining cross members from No. 34 for-ward, also parts No. 12, which form the foot"well" when all cross members are in place. Thefull-length members are not dimensioned, as theymust be cut, fitted and welded in place individ-ually. Not shown is the fourth member from thefront; it's directly over the front axle and is car-ried on two projections, or legs, made by weldingtwo 2-in. lengths of tubing to parts No. 30. It'simportant when fitting and installing these mem-bers to see that they are at right angles to thelengthwise members and to make sure that allwelds are sound, as rigidity and stability of theframe is largely dependent on these members.

Comes then the assembly and installation ofthe front axle which is almost entirely unitized

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from stock materials and parts and is sprung tothe frame with two under-slung 3-leaf springs.The fixed spring shackles, parts No. 13, are ofthe same thickness of material as the free shack-les, but note they are a single piece and bent toa U-shape. The free shackles should have greasefittings installed.

The axle proper is a length of 1-1/4-in. squaresteel tubing with the added rigidity of a steelangle welded to the lower face along the fulllength between the spring mounts. The kingpinyokes are stiffened with triangular braces weldedto the yokes and axle. The kingpins are 3/4-in.bolts, each being counterbored and tapped fora grease fitting, the counterbore extending longi-tudinally about 1-1/2in. to a hole drilled trans-versely at right angles to provide for passage oflubricant.

To get the assembly up on its wheels you nextmake and assemble the rear axle. Here the brakedrum serves both for braking the car and as amounting for the driven sprocket, the latter be-

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ing bolted to an anchor ring which slips ontothe drum and is either brazed or tack-welded inplace. An alternative to the anchor ring is thebrazing of four bolt lugs to the drum, spacedequidistantly. Care must be taken to assure thatthe ring (or lugs) is not only concentric with thedrum, but that it turns true. Even a slight wobblemay cause undue vibration of the chain at higherspeeds. When assembled, the end of the sleevecarrying the plate bolted to the brake drum iswelded to upright No. 32. The weld takes thetorque, or axle wrap, when the brake is applied.

The engine, a Honda Twin Series 150, isbracketed to frame members No. 34 and 40Aand care must be taken to assure that the sup-porting brackets are in the proper position sothat the sprockets line up when the engine is in-stalled. The drive chain is standard cycle chain,the slack being carried on a sprocket idlermounted on a pivoted, spring-loaded bracket.The engine is, of course, equipped with its ownstarter, generator and transmission built in, butthe latter is not provided with reversing gear. Toback the car, an auto starter fitted with an 8-toothsprocket to engage the drive chain is pivoted tothe frame just ahead of the drive wheel andis actuated and energized by means of the leverand linkage No. 26 and 27. To back the car, thedriver lifts the L-shaped lever, No. 27, whichraises the starter by means of the linkage, No. 26.The sprocket on the starter shaft engages thedrive chain and, simultaneously, the driverpresses the pushbutton switch in the end of the

lever, thus energizing the starter. As the starteris raised the pin on the half-circular disk (boltedto the shaft end) deflects the drive chain down-ward at a point just ahead of the sprocket, thuspreventing the latter from disengaging as thestarter is energized. The exploded view of theassembly shows how the starter is pivoted. A1/4-in. rod, threaded at the forward end andfitted with an adjustable yoke, permits correctpositioning of the starter. The starter shaft isshortened to about 1-in. projection and is eithershouldered and threaded, or the sprocket at-tached by means of a hub and key or setscrew.

The brake master cylinder is actuated by thecenter pedal; the left pedal controls the clutchand the right is the accelerator, or gas pedal.Both the latter are similar in construction andassembly, as will be noted in the details. Bothactuate the clutch and fuel feed through flexiblecable controls, part No. 24, leading from thecontrol arms back along the frame to the clutchand carburetor. The control cables should beattached with wrappings of adhesive tape, orbetter, by means of U-shaped metal clips fas-tened with screws turned into tapped holes inthe frame members.

The gearshift lever is directly in front of thereverse lever, both being located midway be-tween the seats. The shift linkage consists of theparts No. 16 and 17, the former connected tothe shifter arm on the engine. The steering-gearhousing is located between the brake and clutchpedals and is shown both in cutaway and ex-

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ploded views, the housing being welded to thesecond cross member of the frame. It's a rela-tively simple assembly but, of course, care mustbe taken to assure correct alignment of thepinion and gear and the shafting. The steeringcolumn passes through an angled slot in the in-strument panel stop, part No. 39A. Lifting thestop permits the column and wheel to tilt approx-imately 20°, thus giving easy access to thedriver's seat. Installation of the seats, fuel tank,floorboards, battery, rear deck and finally theelectricals (according to the Honda manual)completes the chassis.

By careful scrounging in an automotive grave-yard, you can come up with the parts specified,or adaptable substitutes. The prototype wasbuilt with the steering wheel from an old car,the fuel tank from a racing kart, and the bucketseats from a foreign car. All three wheels, in-cluding tires (4.80 by 16), brake drums, andleaf springs, were taken from a Gator boat trailer.

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