A very simple and strong toy automobile truck may be made of tin cans. If the foregoing problems have been carefully worked out, there is no reason why one should find the truck difficult to make, provided the directions are carefully followed.

As the construction of a truck is typical of so many wheeled toys, it was selected as the best type with which to begin. Various fittings may be added, such as lights, fenders, running boards, handles, tool boxes, etc., but only after the plain truck chassis, hood, seat and wheels have been successfully assembled. This first real problem in toy making should be kept as simple as possible.

Wheels form the most important part of any rolling toy, so these will be taken up first and each method of making them discussed at length.

Four Ways of Making Wheels of Tin Cans.—Both types of tin cans may be used for making wheels, the rolled rim and the soldered flange can, but the method of making the wheel is different for each type of can. The press-in can lids from molasses and syrup cans may also be used for making wheels.

Making a Wheel from a Can with Soldered Ends.—Suitable truck wheels may be made from the smallest size evaporated milk cans. Condensed milk cans are too large for a small truck, though either of the above mentioned cans have the soldered flanged ends.

The contents of these evaporated milk cans is usually poured through one of two holes punched through the cover. This renders the cover practically useless for making one side of the wheel, unless the holes are small, so that eight cans will have to be used for making four wheels.

If the cans are opened on the side with a can opener but four cans need be used, as each end of the can is then intact. These wheels are made by removing one lid from the can, cutting the can down to the required wheel width, and then soldering on the lid again. When the ends of the can are intact, the can is cut in two parts by cutting around the sides of the can with the can opener. One part of the can is cut down to the required height as in making a tray; this height represents the width of the wheel. The end is melted off the other part of the can and this end is placed over the first part of the can that is cut to the width of the wheel. It is then soldered in place and the wheel is made.

If plenty of evaporated milk cans are not handy, it is better to buy four new, filled cans from the grocer, as these small cans cost only eight cents when filled with milk.

Empty the cans by cutting a slit in the side with a sharp can opener, see Fig. 43. Hold the cans over a glass or jar until the milk runs out into the glass, then rinse the cans out with hot water which will also remove the label. Continue cutting around the can with the can opener until it is completely cut in half. All four cans should be emptied and cut in two in this manner. As for the milk, any cook will know what to do with that.

Open the dividers to ? inch and scribe a line around the bottom of one of the cans that has been cut in two, using the soldered edge of the rim against which to rest one point of the dividers, as shown in Fig. 44. Cut away the surplus tin exactly as if you were making a tray. If the cans have become dented when they were being cut with the can opener, place them on a round anvil and remove the dents by hammering gently with a mallet.

Take up another half can and make a cut from the edge down to the flange at the bottom as shown in Fig. 45. Take an old pair of flat-nosed pliers and hold it over an open flame, such as a gas range or the flame of a soldering copper heater, until the solder shows in a bright line at the joint of the can and lid, then take the forming mallet and give the lid at the bottom a sharp tap or two with it which should knock the lid away from the sides of the can held by the pliers, see Fig. 45. Do not use your good pliers to hold the can over the flame, as the heat will soon take the temper out of them and render them useless.

It is not necessary to get the can red hot in order to melt the solder.

When the lid is removed, try to fit it on the other part of the can and it will be found impossible to force the tin into the lid without denting the sides of the can. The rim or flange at the edge of the lid must be enlarged in order to place the lid back on the can. The edge of the sides of the can to be fitted into the lid should be filed with a small flat file to remove the tin raised by the metal shears when cutting around the can.

To enlarge the rim of the lid, place it over a piece of pipe held in a vise and hammer the rim with a light hammer, turning the lid slowly around on the anvil as you hammer, see Fig. 46. After hammering completely around the flange once or twice, try to fit the lid to the can again. It should fit without much hammering. Squeeze the lid on the can and hammer it gently into place, the wheel being placed flat on the bench at the time. Solder the lid in place and the wheel is finished except for the axle holes.

A small drop of solder will be found on the lid of all evaporated milk cans. Melt this away with a hot soldering copper and a round hole will be found exactly in the center of the lid. This hole may be enlarged to fit the wire used for the axle.

Find the center of the side of the wheel with the dividers as described on page 37, Chapter II.

Use an ice pick to punch a tiny hole exactly in the center of the wheel. If ?-inch galvanized wire is to be used for an axle, push the ice pick further into the hole, turning the pick while doing so, until the hole is just large enough to fit the axle wire. Repeat the process on the other side of the wheel until the hole there is enlarged to fit the axle wire, Fig. 47.

If the axle holes are not exactly in the center of the wheel, it will not run true. A little care used in punching the holes will cause it to run true enough for any toy.

If you possess a hand drill and a drill the same size of the wire used for an axle, you may drill the hole in the center of the wheel instead of punching it through. To do this, first find the center of the wheel and then make a slight dent exactly in the center of the wheel with the ice pick or a small center punch. The point of the drill is placed in this dent when starting to drill the hole. I find it better to use a ?16-inch drill and drill a hole through the center of the wheel with this first, then use a drill the same size as the axle wire and enlarge the ?16-inch hole with this.

In any case, the wheel should be soldered together before the holes are put through the centers. Finish up the four wheels and lay them aside until the truck is nearly completed, as the wheels are the last things to be added.

Galvanized wire of ? or ³/16 inch diameter is usually used for axles. This wire is usually carried in stock at hardware stores. It is usually furnished in coiled form and must be straightened out before being used. A piece is cut from the coil of wire long enough to make the two axles. It should then be placed on a flat metal surface and hammered straight.

Making Wheels from Rolled-Rim Cans.—A very strong wheel may be used from rolled-rim cans. This process is slightly different from that used with the soldered flange cans. Wheels from 2½ to 6 inches in diameter may be made by this second method, but unless this type of wheel is made from very small cans it is not so suitable for the truck as the wheels made from small evaporated milk cans.

Eight rolled-rim cans will have to be used to make four wheels unless the cans are opened at the side when first emptied. Both types of wheels should be made so as to become familiar with the making of each type, as both types are used in making the models shown in this book.

This second type of wheel is rather easier to make than the first, but you should know how to make either type, as then many different sizes of wheels may be made with whatever cans you may have. The rolled rim is more often employed in making large cans than in the smaller ones.

To make wheels suitable for a truck of the size described here, small soup cans may be used; these are usually rolled-rim cans.

To make a wheel from two rolled-rim cans, a line should be scribed about the base of the can, ? inch from the bottom, and the can cut down to this line, see Fig. 48, A. Scribe a line ¼ inch from the base of the second can and cut this can down to this line. Make a cut every ¼ inch around the tin at the side of this second can, each cut to reach the base or rim of the can, see Fig. 49, B.

Place this part of the wheel on the wooden block and use the riveting hammer (C) to drive the cut side of the can inward as shown in Fig. 49, B.

Now take up the can cut down to ? inch and place it over a pipe anvil which is held in the vise. Use a metal hammer and hammer around the edge of this can two or three times to enlarge it. Turn the can around the anvil when hammering it. Then try to push it down over the second or turned part of the second can as shown in Fig. 49, D. If it does not fit, continue the hammering until the two parts of the wheel fit together and then solder them in place and the wheel is completed, except for the axle holes, which may be put in exactly the same way as they are put in the first type of wheel.

The large roller of the toy steam roller shown in Plate IX is made of rolled-rim cans as are the large wheels of the toy traction engine shown in Plate XVIII.

Be sure to try both methods until you understand them thoroughly, as a great deal depends on the ability to make good wheels for a toy model.

Two Types of Wheels Made from Can Lids.—A third method of making wheels is to use two can lids soldered together, but as it takes quite a while to collect eight can lids of the same diameter, it is better to employ this method only occasionally, as for flanged car wheels made to run on a track, etc. A glance at Fig. 50, A, should be enough to show how these wheels are made up of two pushed-in can lids soldered together at their largest diameter.

The first two methods described result in wheels that look like the heavy truck wheels employed on actual trucks.

Another type of wheel may be built of the flanged pushed-in lids. In this type the lids are soldered together in just the opposite way as that described in the third method, so that the flanges are on the outside of the wheels. These wheels are generally used for belt wheels on the mechanical models, Fig. 50, B.