Ornamental chapter heading

Ornamental chapter headingA Boys’ Motor CarHOMEMADEby P.P. Avery

A Boys’ Motor CarHOMEMADEby P.P. Avery

Eventhough the home-built “bearcat” roadster, or other favorite model, does not compare in every detail with the luxurious manufactured cars, it has an individuality that puts it in a class by itself. The amateur mechanic, or the ambitious boy, who is fairly skilled with tools, can build at least the main parts for his own small car, of the simple, practical design shown in the sketch and detailed in the working drawings. If necessary, he can call more skilled mechanics to his aid. A motorcycle engine, or other small gasoline motor, is used for the power plant. The control mechanism of the engine and the electrical connections are similar to those of a motorcycle. They are installed to be controlled handily from the driver’s seat. The car is built without springs, but these may be included, if desired, or the necessary comfort provided—in part at least—by a cushioned seat. Strong bicycle wheels are used, the 1¹⁄₂ by 28-in. size being suitable. The hood may be of wood, or of sheet metal, built over a frame of strap iron. The top of the hood can be lifted off, and the entire hood can also be removed, when repairs are to be made. The tool box on the rear of the frame can be replaced by a larger compartment, or rack, for transporting loads, or an extra seat for a passenger.

To Simplify This Small but Serviceable Motor Car for Construction by the Young Mechanic, Only the Essential Parts are Considered. Other Useful and Ornamental Features may be Added as the Skill and Means of the Builder Make Possible

The construction may be begun with the chassis and the running gear. Fit the wheels with ⁵⁄₈-in. axles, as shown in the assembly views,Figs. 1,2, and3, and detailed inFig. 4. Fit the ends of the axles to the hubs of the wheels, providing the threaded ends with lock nuts. Make the wooden supports for the frame, as detailed inFig. 6. The axles are fastened into half-round grooves, cut in the bottoms of the supports, and secured by iron straps, as shown inFig. 4, at A. Make the sidepieces for the main frame 2¹⁄₂ by 3¹⁄₄ in. thick, and 9 ft. 4 in. long, as detailed inFig. 7. Mortise the supports through the sidepieces, and bore the holes for the bolt fastenings and braces. Glue the mortise-and-tenon joints before the bolts are finally secured. Provide the bolts with washers, and lock the nuts with additional jam nuts where needed. Keep the woodwork clean, and apply a coat of linseed oil, so that dirt and grease cannot penetrate readily.

Finish only the supporting structure of the chassis in the preliminary woodwork. Set the front-axle and steering-rigging supports C and D, and adjust the spacers F between them. Bore the hole for the kingbolt, as detailed inFig. 6, and fit the bevel gears and the fifth wheel G, of ¹⁄₄-in. steel, into place, as shown inFig. 5. The gear H is bolted to the axle support. Thepinion J is set on the end of a short ³⁄₄-in. shaft. The latter passes through the support D, and is fitted with washers and jam nuts, solidly, yet with sufficient play. A bracket, K, of ¹⁄₄ by 1³⁄₄-in. strap iron, braces the shaft, as shown inFig. 3. The end of this short shaft is joined to one section of the universal coupling, as shown, and, like the other half of the coupling, is pinned with a ³⁄₁₆-in. riveted pin. The pinion is also pinned, and the lower end of the kingbolt provided with a washer and nut, guarded by a cotter pin. Suitable gears can be procured from old machinery. A satisfactory set was obtained from an old differential of a well-known small car.

Fig. 8Detail of the Motor Support: The Engine is Mounted on Reinforced Angle Irons, and Secured by Clamps and a Supporting Band under the Crank Case

Before fitting the steering column into place, make the dashboard, of ⁷⁄₈-in. oak, as shown in the assembly view, and in detail inFig. 7. It is 19¹⁄₂ in. high and 2 ft. 4 in. wide, and set on the frame and braced to it with 4 by 4 by 1¹⁄₂-in. angle irons, ¹⁄₄ in. thick. Fit a ⁷⁄₈-in. strip of wood around the edge of the dashboard, on the front side, as a rest for the hood, as shown inFigs. 1and7, at L. A brass edging protects the dashboard, and gives a neat appearance. Lay out carefully the angle for the steering column, which is of ⁷⁄₈-in. shafting, so as to be convenient for the driver. Mark the point at which it is to pass through the dashboard, and reinforce the hole with an oak block, or an angle flange, of iron or brass, such as is used on railings, or boat fittings. A collar at the flange counteracts the downward pressure on the steering post. The 12-in. steering wheel is set on the column by a riveted pin.

The fitting of the engine may next be undertaken. The exact position and method of setting the engine on the frame will depend on the size and type. It should be placed as near the center as possible, to give proper balance. The drawings show a common air-cooled motor of the one-cylinder type. It is supported, as shown inFigs. 1and3and detailed inFig. 8. Two iron strips, B, riveted to 1¹⁄₂ by 1¹⁄₂-in. angle irons, extend across the main frame, and support the engine by means of bolts and steel clamps, designed to suit the engine. Cross strips of iron steady the engine, and the clamps are bolted to the crank case. The center clamp is a band that passes under the crank case.

The engine is set so that the crankshaft extends across the main frame. Other methods may be devised for special motors, and the power transmission changed correspondingly. One end of the crankshaft is extended beyond the right side of the frame, as shown inFig. 3. This extension is connected to the shaft by means of an ordinary setscrew collar coupling. A block M,Figs. 3and7, is bolted to the frame, and a section of heavy brass pipe fitted as a bearing.

The ignition and oiling systems, carburetor, and other details of the engine control and allied mechanism, are the same as those used on the motorcycle engine originally, fitted up as required. The oil tank is made of a strong can, mounted on the dashboard, as shown inFigs. 1and2. It is connected with the crank case by copper tubing. A cut-out switch for the ignition system is mounted on the dashboard. The controls used for the engine of the motorcycle can be extended with light iron rods, and the control handles mounted on the dashboard or in other convenient position. The throttle can be mounted on the steering column by fitting an iron pipe around the post and mounting thispipe in the angle flange at the dashboard. A foot accelerator may also be used, suitable mountings and pedal connections being installed at the floor.

In setting the gasoline tank, make only as much of the body woodwork as is necessary to support it, as shown inFigs. 1,3, and7. The tank may be made of a can, properly fitted, and heavy enough, as determined by comparison with gasoline tanks in commercial cars. The feed is through a copper tube, as shown inFig. 1. A small venthole, to guard against a vacuum in the tank, should be made in the cap. The muffler from a motorcycle is used, fitted with a longer pipe, and suspended from the side of the frame.

The transmission of the power from the motor shaft to the right rear wheel is accomplished by means of a leather motorcycle belt, made by fitting leather washers close together over a bicycle chain, oiling the washers with neat’s-foot oil. A grooved iron pulley is fitted on the end of the motor shaft, and a grooved pulley rim on the rear wheel, as shown inFigs. 1and3, and detailed inFig. 4. The motor is started by means of a crank, and the belt drawn up gradually, by the action of a clutch lever and its idler, detailed inFig. 9. The clutch lever is forged, as shown, and fitted with a ratchet lever, N, and ratchet quadrant, O. The idler holds the belt to the tension desired, giving considerable flexibility of speed.

The brake is shown inFigs. 1and3, and detailed inFigs. 4and9. The fittings on the rear wheel and axle are made of wood, and bolted, with a tension spring, as shown. The brake drum is supported on iron bands, riveted to the wheel, and to the pulley rim. The brake arm is connected to the brake wheel by a flexible wire. When the pedal is forced down, the wire is wound on the brake wheel, thus permitting of adjustment. The pedal is of iron and fixed on its shaft with a setscrew. An iron pipe is used as a casing for the central shaft, the shaft carrying the clutch lever, and the pipe carrying the brake pedal and the brake wheel. The quadrant O is mounted on a block, fastened to the main frame. The central shaft is carried in wooden blocks, with iron caps. A catch of strap iron can be fitted on the floor, to engage the pedal, and lock the brake when desired.

DETAIL OF BRAKE AND CLUTCH LEVERFig. 9The Brake is Controlled by a Pedal, and a Clutch Lever is Mounted on the Central Shaft, and Set by Means of a Ratchet Device and Grip-Release Rod

DETAIL OF BRAKE AND CLUTCH LEVERFig. 9

The Brake is Controlled by a Pedal, and a Clutch Lever is Mounted on the Central Shaft, and Set by Means of a Ratchet Device and Grip-Release Rod

The engine is cooled by the draft through the wire-mesh opening in the front of the hood, and through the openings under the hood. If desirable, a wooden split pulley, with grooved rim and rope belt, may be fitted on the extension of the engine shaft, and connected with a two-blade metal fan, as shown inFig. 2.

The lighting arrangement may next be installed, gas or electric lamps, run on batteries, being used. Mudguards are desirable if the car is to be used on muddy roads. Strong bicycle mudguards can be installed, the guard braces being bolted on the axles. A strong pipe, with a drawbolt passing through its length, is mounted across the front of the frame. The body is built of ⁷⁄₈-in. stock, preferably white wood, and is 2 ft. 4 in. wide. A priming coat should be applied to the woodwork, followed by two coats of the body color, and one or two coats of varnish. The metal parts, except at the working surfaces, may be painted, or enameled.

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