This Sidewalk Runabout is Easy to Build (May, 1938)
This Sidewalk Runabout is Easy to Build
By Hi Sibley
THERE is one definite rule to follow in making a sidewalk automobileâ€”get your engine first and build the car around it. This applies pretty much to the wheels, too.
A half-horsepower, two-cycle washing machine engine is available in nearly all sections of the country, and as these can be had second-hand at a reasonable price and have sufficient power for moderate speeds, they make satisfactory installations. Herewith are working drawings of the little car owned by Richard Weber, of San Marino, California, which is driven by this type of motor and has proved successful for a long period. It is very easy to build.
In Figs. 1, 2 and 3 are given the general over-all dimensions. Note that the front wheels have a wider tread than the rear. This permits a shorter turning radius, and brings the back wheels in close to the power unit. The engine is provided with a kick starter, and the clutch arrangement consists of an idler pulley which tightens the single drive-belt when the hand lever is pushed forward. When pulled back, it operates the brake. Drive is on one wheel, brake on two.
Hood, seat-back and dummy radiator are of galvanized iron cut as shown in Fig. 12. These dimensions are approximate as a certain amount of fitting is always necessary for curved members. If you have the facilities, the edges of the metal should be beaded. The edge of the seat back is protected with a strip of leather laced on with rawhide. It will be best to leave the cutting of the hood, etc., until the chassis is completed.
Several types of wheels are available for small autos, being manufactured by toy makers, tire companies, etc. The original car in the photos has disk wheels with the brake drum and pulley cast integral, and turned down on a lathe, as in Fig. 11. This of course requires a pattern. Another very satisfactory wheel used by the writer for several small power vehicles is a 3-inch by 12-inch disk with balloon tire. It is assembled with six small bolts through the hub, and by substituting longer ones for these, a combination brake-drum and drive pulley can be bolted securely to the wheel. A spacing ring will be necessary to hold the drum away from the tire, as illustrated in Fig. 11.
The rear wheels turn on a stationary steel axle. This is secured to the wooden cross-member at rear of frame by means of J-bolts, simply a Va -inch carriage bolt with the head cut off and the end bent as shown in Fig. 6. Steering knuckles and a built-up axle are used on the front end, Fig. 9. Construction of these parts requires welding, bending and drilling only, and the wheel spindle must be turned to accommodate the standard wheel bearings.
Figs. 4 & 5 show the complete chassis assembly. The sills or stringers are 1-1/2×2-inch oak, with 2×4-inch oak cross-members where indicated. The chassis is 4 inches wider at back than in front. After the front axle is bolted to the sills, a pipe nipple socket for the bottom end of the steering post is installed. A plywood floor is then carried as far as the back of the seat. Upon this is erected a strap iron frame to support the upper end of the steering post as well as hood. The steering wheel may be either a full size auto wheel, or a hardwood rim screwed to a cut-down Model-T spider.
For the hand lever a pipe, bar or section of seamless steel tubing is bent to a right angle and carried in a pair of bearings screwed under the sills, as shown in Fig. 4. An arm is welded onto the lever for attaching the brake cables and a yoke and link connect the lever with the idler pulley assembly.
Fender bars protect the rear wheels, and the engine bed is mounted on the rearmost cross-member and one just behind the seat. The brakes consist of brake-lining riveted to a shoe made in the form shown in Fig. 7, which is welded to a sliding bar, carried in a sheet steel guide screwed to the chassis sill. A tension spring holds it away from the brake drum when not applied.
A very satisfactory clutch consists of an idler pulley mounted on a sliding bar as in Fig. 8. This tightens the belt on the drive pulley and starts the little car smoothly. As this type of engine is not arranged for variable speed, no controls are necessary, unless a shorting switch, convenient to the hand while driving, is desired.
Various makes of engines can be used in this car, the drive arrangement being identical. For only one-half horsepower, have your wheel-pulley at least 9 inches in diameter. This will not give any startling speed, but enough power.