SIDEWALK PLAY CAR

By Elmer V. Clark ance for bandsawing the curved sections atboth ends of each piece. Use waterproofglue in the joints. After the glue is dry,bandsaw the curved ends and plane andsand the parts to the finished size. Apply acoat of shellac to prevent absorption ofmoisture. The side frames are joined nearthe ends with long studs, or draw bolts, andpipe spacers as shown on the blueprint ona following page. Note that the front andrear-spring shackles are mounted on thedraw bolts and that these must be left looseso that the shackles can move freely. Notealso that the brake pedal is pivoted on thesame draw bolt as the front-spring shackles.In this case two spacers are used to serveonly as collars to position the pedal. Exactsizes of the draw bolts and spacers are notimportant.

Note especially the construction and

IVELY youngsters and craftsman fa-thers alike will get a thrill out of this

tiny play car, which looks and drives like areal automobile except that it's scaled downto sidewalk-coaster size and travels at slow,safe speeds. It's driven by an auto startermotor of the type having a built-in reduc-tion gear and is fitted with a foot brake, lev-er-operated clutch, pneumatic tires anda conventional steering gear. As picturedabove, the original car measures 58 in. over-all length, with a 42-in. wheelbase and 20-in. tread, but allowable variations in dimen-sions and the necessity of adapting certainparts according to availability, may changethese dimensions slightly. For these reasonscertain dimensions have been purposelyomitted and adaptation or substitution ofparts has been left to the discretion of thebuilder. An example is the length and typeof the springs specified in the constructiondetails. Obviously, these can be longer, oreven slightly shorter than the lengths given.The side frames are of 2 x 2-in. oak and, inorder to avoid waste in forming the curvedends, or lifts, the members are built up tothe rough shape by gluing together stripsof ¾-in. stock. Before gluing the strips to-gether, be sure that there is ample allow-

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174 POPULAR MECHANICS

POPULAR MECHANICS

mounting of the front and rear axles on thesprings. The front axle is fitted with drilledpads to which the underslung springs arebolted, but at the rear it will be noted thatthe axle bearings serve as spring pads.Shims of 1/8-in. flat steel are placed betweenthe spring and the bearings, one shim beinglonger and having a drilled lug welded nearthe forward end to provide a bearing forthe brake shaft when the band-type brakeis used. When the shoe-type brake, shownin the detail above, is used, the brake-shaftbearing is attached to the car frame.

The front axle is of the conventional auto-type construction, the principal parts beingmade from pipe and flat steel, bent, weld-ed and bolted together as in the blueprint.The drag link and tie rod can be taken fromFord Model-A steering linkage. Crosley or

American Austin parts may be substituted.Rods with ball joints also can be impro-vised. A Crosley or Austin steering gear canbe used, the gear being mounted on a brack-et under the hood. The steering shaft is ap-proximately 22 in. long and ½ in. in diame-ter and is mounted on a generator bearingat the top end. The lower end of the shaft isfitted into an adapter sleeve, the size andlength of the sleeve depending on the typeof steering gear used. The steering wheelis 8 in. in diameter, the original being takenfrom a discarded toy.

Although details on the blueprint showthe starter motor welded to a rocker shaft,which passes through a hole drilled in theflange of the reduction-gear housing towhich it is welded, for best results weld abracket to the gear housing and then weld

the free end of the bracket to the rockershaft. This construction will give a some-what better clutch action when tighteningand slackening the double V-belts with theclutch lever. The rocker shaft turns in bear-ings bolted to the side frames. The clutchshaft, with its tension spring, is mounted inthe same manner. Use a 2-in. V-pulley onthe reduction gear and a 5-in. pulley on therear axle. Although double V-pulleys areshown, single-groove pulleys will serve thepurpose quite satisfactorily. Only the right-rear ground wheel is fixed on the axle andserves as a driver. The left rear wheel turnsfree. This arrangement gives the necessarydifferential when turning.

Details on pages 174 and 175 give the wir-ing diagram, construction of the batterybracket and the position of the controls.Note the arrangement of the brake switchand how it works in the motor circuit. Whenit is desired to stop, the clutch lever ispushed forward and the brake pedal de-pressed. A small lug welded to the innerend of the clutch-lever shaft opens thebrake switch and stops the starter motor.The motor cannot be started until the clutchlever is pulled part way back. This arrange-ment prevents undue idling of the startermotor. With the pulley sizes given and withthe gear ratios of the average reduction-gear starter motor, the car travels at a speedof approximately five miles per hour. A6-volt, 130-amp. battery will give abouteight hours of service on one charge.

Construction of the sheet-metal body isquite simple. It is made in three sectionswhich consist of the hinged rear deck, thedriver's compartment and the hood, whichincludes the separate false grille. The pat-tern for the grille is first laid out on 2-in.squares and then cut to the form shown,before bending and soldering. Sides of thecockpit and the hood are attached to theside frames with screws uniformly spaced.The seat bottom, floor boards and dash arecut from ½-in. plywood. The seat can beupholstered if desired. Bumpers, dummylights and other fittings are optional withthe builder.