CHAPTER XI

MAKING A TOY AUTO TRUCK (_Continued_)

FORMING THE CHASSIS—USING THE WOODEN ROOFING FOLDER—FOLDING—USING THE VISE FOR SHORT FOLDING—USING THE HATCHET STAKE FOR FOLDING

=Forming the Chassis.=—The chassis or frame of the truck may be made from a single piece of tin cut from a gallon fruit can. All four edges are turned down so as to form a shallow tray or box.

Cut a piece of tin 12¾ by 4¼ inches. Use the dividers to mark off a line ⅜ of an inch inside all four sides, but be sure that the tin is cut perfectly square before you do this inside marking. Cut in to the lines A A on all four of the darkened lines as shown in Fig. 51, _A_.

Place the tin on a sharp-edged block and fold down the long sides 1 and 2 first. Remember not to try to fold these long sides or folds down all at once, but rather go over them two or three times lightly with the mallet as they are being turned down at a right angle. Take care that the tin folds over exactly at the line.

When the sides 1 and 2 are folded down at right angles, fold down the ends 3 and 4. This will leave four small ends of the two long sides projecting beyond the ends as shown in Fig. 51, _B_. Fold these in over the ends of the chassis with a mallet. Hold them in place with a pair of flat-nosed pliers and solder them to the ends where they touch, so that the chassis appears as shown in Fig. 51, _C_.

=Using the Wooden Roofing Folder.=—Folds of all kinds may be very easily and quickly made by using the wooden roofing folder, Plate XII. The work turned out by this simple machine is very straight and true, particularly long folds or angles of tin. The gauge may be set at any desired width up to ⁷⁄₁₆ of an inch and any number of folds of the desired width can be quickly and accurately produced by inserting the tin between the holding bars and closing up the folder.

The holding bars are shown at _A A_, Fig. 52. The adjustable gauge at _B_, _C C_ are the wooden supports which are hinged together. _D_ is the iron handle, _E_ the adjusting screw, _F_ is the piece of tin to be folded.

The folder is shown in Fig. 53. Both of these views are sectional to show the working of the folder. The actual construction may be easily understood by looking at the actual folder. The gauge _B_, Fig. 52, is adjusted by first loosening up the five screws _E_ with a screw driver and then pulling in or pushing out the gauge _B_ to the desired width of the fold to be made. The screws _E_ are then tightened up with the screw driver and the tin inserted between the pieces _A A_. The folder is then closed by grasping the handle _D_ and closing the two sides of the folder together. When the folder is opened, the tin will be found to be folded over.

The fold may then be completed with the mallet if it is desired to close it up against the tin. To form a right angle the folder is not completely closed. A little experimenting with a piece of scrap tin will show how far to close the folder in order to obtain a given angle.

Care should be taken to set the gauge _B_ parallel with the holding bar _A_. The folder is ordinarily set at ¼ inch. This is the width of most of the folds made in the tin. This simple machine will save much time in tin working and one should be purchased if possible. It is practically the only way a long fold in a narrow strip of tin may be made accurately.

The folder may be used to fold down the two long sides of the chassis, the ends may then be turned down over the edge of a block as the ends of the long folds will prevent placing the short folds in the folder. Narrow strips of tin may be folded over and hammered together with the mallet. These strips of tin may be slipped over the sharp edges at the bottom of each side of the chassis, thus making the edges very strong and removing the danger of cutting the fingers. Fig. 51, _D_, shows an enlarged view of a corner of the chassis with the folded tin strips slipped over the lower edges.

These narrow folded strips are very easily made on the folding machine. Cut two strips of tin ½ by 12 inches and set the folder to fold ¼ inch, place the tin in the folder and fold it over. Remove it from the folder and hammer it nearly together with the mallet and then place a separate strip of tin in the folded part and continue hammering with the mallet until the folded tin is closed in on the inside or inserted strip of tin.

The folded strip is then ready to slip over the edge of the side of the chassis and to be soldered to it in several places; that is, the folded strip need not be soldered to the chassis continuously, but may be held in place by soldering about every four inches.

The two short strips of tin ½ by 4 inches should then be cut, folded and soldered in place at the short ends of the chassis. (No sharp edge should be left about a tin can toy when it may be avoided by folding or covering.)

A long narrow strip of tin is rather difficult to fold without the use of a folder, but it may be done with the mallet and block as follows:

=Folding.=—If a strip of tin ½ by 12 inches is to be folded over, it is better to cut a strip of tin 1¼ by 12 inches. Mark off ¼ inch all along one long edge and fold it down over a block as in making the handle of the cooky cutter, for you will then have more metal to hold to while folding. When the piece is completely folded down to a right angle, turn it over on the block and close the tin down with a mallet, inserting a piece of tin before closing the tin together. Then the surplus tin may be cut away and you have a narrow folded strip. As in all folding by hand using the mallet and the block, the tin should be gradually folded into place.

=Using the Vise for Short Folding.=—The vise may be used to fold short pieces of tin very accurately. The folding line is first marked on the tin; the tin is then placed and held in the vise jaws so that the line is parallel with and exactly at the top of the jaws. The mallet is then used to hammer the tin over to the required angle, see Fig. 54. A very sharp accurate fold should result.

=Using the Hatchet Stake for Folding.=—A special stake has been devised for folding tin. This is called the hatchet stake and is listed in the supplementary tool list. It is made in the shape of the letter T. The horizontal part is made like a long narrow-bladed hatchet, and the vertical shank attached to it may be held in the vise or set in a hole in the bench, see Fig. 55.

The top edge of this tool is perfectly straight and fairly sharp. One side of the blade runs straight down from the edge and the other side slopes down at an angle considerably less than a right angle. The top edge of the hatchet stake is used to fold the tin over and it is specially formed to permit the folding of more than a right angle.

To use the hatchet stake, a folding line is first marked on the tin. This line is kept directly over and parallel with the top or edge of the stake and the mallet is used to fold the tin, the mallet blows being directed at the top of the stake as shown in Fig. 56.

The hatchet stake is a very handy tool about the shop, even if a folder is included in the equipment, as there are some jobs that will not permit the use of the folder to complete them.

Strips of tin as long as the blade of the hatchet stake may be accurately folded over as follows:

A strip of maple 1 inch thick and 2 inches wide and as long as the blade of the stake may be clamped against the flat side of the blade of the hatchet stake with the tin to be folded held tightly between the maple strip and the blade. The mallet is then used to fold the tin over toward the sloping side of the blade, Fig. 57. Sometimes two strips of maple may be clamped to a piece of tin to hold it accurately while being folded, but this method is rather cumbersome.

The different methods of folding have been described at length so that the reader may become familiar with all of them, but a great deal of folding may be done over a sharp-edged maple block, if you have nothing else with which to work.

Professional tinners use a very convenient folding machine made of metal, but these are very costly and need not be described here.