from an early 1930's issue of Industrial Arts & Vocational
Education magazine.
In machine-shop practice it is necessary to do a great deal of filing, especially in assembling finished jobs. This often necessitates filing flat surfaces, which is a difficult operation unless one has some way to hold the file properly.
The file holder described herewith has been found to solve this problem very nicely. The construction is not difficult and the holder can be made in a school shop equipped with a lathe, drill press, and shaper. It is so designed that it will take a 10-, 12-, 14-, and 16-in. file.
The brace and tie rod may be forged in the forge shop, thereby furnishing that department with a practical project. The aluminum handle may be cast in the foundry or it may be turned from a bar of aluminum. The wooden handle may be purchased or it may be made in the woodshop.
Making the File Holder
In making the tie rod the lathe and shaper are used. Put the rod in the vise of the shaper and shape the slot for the end of the file. Remove the live center-from the headstock of the lathe and chuck the tie rod. Shove the rod back to within about an inch of the end on which the thread is required. Before chucking, a center should be put in the end of rod so the center in tailstock can be used to hold job firm. If it is not convenient to cut the tread in a lathe, it may be cut with solid dies.
In making the brace, the part that rests on the file should be shaped in the shaper. This is the only part of the brace that needs finishing. The hole is drilled on the drill press and the hole countersunk the desired radius of the brass bushing in the aluminum handle. This is done by grinding the countersink drill to the desired radius.
In making the aluminum handle, place it in the lathe chuck, and counterbore for the brass bushing. Then drill a 3/8-in. hole all the way through the handle for clearance for the threaded part of the tie rod. The outside of the handle may then be turned to the desired size.
The brass bushing should be made of round brass. Place a piece about 3 in. long in the lathe chuck, leaving approximately 1 5/8 in. projecting beyond the chuck. Drill the hole 1/4 in. to allow for tapping. Turn the outside allowing about one thousandth of an inch for a tapping fit. Tap the hole with a 5/16-in. U.S.S. tap. Cut off to the desired length with a bent cutting-off tool.
Drill a hole, slightly smaller than the tie rod, near the slot end of the rod in the wooden handle.
File the parts and assemble the job as per assembly drawing.
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