The Boy Mechanic Part 63

Begin work by moistening the leather on the back side with a sponge or cloth. Moisten as much as you dare and still not have the moisture show on the face side. Next place the leather on the gla.s.s, face up, and, holding the pattern firmly in place so that it will not slip--if possible get some one to hold the pattern for you--place the straight edge on the straight lines and mark out or indent. After this has been done, mark over the design. A pencil may be used the first time over.

The pattern is now to be removed and all the lines gone over with the tool to make them deep and uniform.

The surplus stock around the edges may not be cut off. A neat way to finish the edges is to punch a series of holes entirely around through which a thin leather thong may be laced. If it is desired to "line" the inside, this should be done before the holes are punched or the lacing done.

** Gear for Model Work [225]

When a gear is needed to drive a small pinion and there is none of the right size at hand, one can be made in the following manner: Turn up a wood disk to the proper diameter and 1/4 in. thicker than the pinion, and cut a flat bottom groove 3/16 in. deep in its face. The edges should be about 1/8 in. or more thick on each side. Measure the distance between centers of two adjacent teeth in the pinion and step this off around the periphery in the bottom of the groove. Drill holes into the wood on each point stepped off and insert steel pins made of wire, allowing

[Ill.u.s.tration: Steel Pins in Wood]

the end of each to protrude just far enough to act as a tooth. In this way a good gear for light work can be quickly and cheaply constructed.

--Contributed by Henry Schaefer, New York City.

** A Home-Made Vise [226]

While making a box I had some dovetailing to do, and as there was no

[Ill.u.s.tration: Vise on Bench]

vise on the bench I rigged up a subst.i.tute. I secured a board 3/4 in. thick, 3 in. wide and 20 in. long and bored a 1/2-in. hole through it, 1 in. from each end. The board was then attached to the bench with two screws pa.s.sing through washers and the two holes in the . board into the bench top. The screws should be of a length suitable to take in the piece to be worked. --Contributed by A. M. Rice, Syracuse, New York.

** Cardboard Spiral Turned by Heat [226]

A novel attraction for a window display can be made from a piece of stiff cardboard cut in a spiral as shown in Fig. 1. The cardboard should be about 7 or 8 in. in diameter. Tie a piece of string to the center point of the spiral

[Ill.u.s.tration: Spiral Cut from Cardboard]

and fasten it so as to hang over a gas jet, Fig. 2. A small swivel must be put in the string at the top or near the cardboard, if it is desired to have the spiral run for any length of time. The cardboard will spin around rapidly and present quite an attraction.

--Contributed by Harry Szerlip, Brooklyn, N. Y.

** A Workbench for the Amateur [226]

The accompanying detail drawing shows a design of a portable workbench suitable for the amateur woodworker. This bench can be made easily by anyone who has a few sharp tools and a little spare time. If the stock is purchased from the mill ready planed and cut to length, much of the hard labor will be saved. Birch or maple wood makes a very good bench. and the following pieces should be ordered:

4 legs, 3 by 3 by 36.

2 side rails, 3 by 3 by 62-1/2 in.

2 end rails, 3 by 3 by 20 in.

1 back board, 1 by 9 by 80 in.

1 top board, 2 by 12 by 77 in.

1 top board, 1 by 12 by 77 in.

2 crosspieces, 1-1/2 by 3 by 24 in.

1 piece for clamp, 1-1/2 by 6-1/2 by 12 in.

1 piece for clamp, 1-1/2 by 6-1/2 by 14 in.

4 guides, 2 by 2 by 18 in.

1 screw block, 3 by 3 by 6 in.

1 piece, 1-1/2 by 4-1/2 by 10-1/2 in.

Make the lower frame first. Cut tenons on the rails and mortise the posts, then fasten them securely together with 3/8 by 5-in.

lag screws as shown. Also fasten the 1-1/2 by 3 by 24-in. pieces to the tops of the posts with screws. The heads should be countersunk or else holes bored in the top boards to fit over them. Fasten the front top board to the crosspieces by lag screws through from the under side. The screws can be put in from the top for the 1-in. thick top board.

Fasten the end pieces on with screws, countersinking the heads of the vise end. Cut the 2-in. square holes in the 1-1/2 by 4-1/2 by 10-in. pieces for the vise slides, and fit it in place for the side vise. Also cut square holes in the one end piece for the end vise slides as shown. Now fit up the two clamps. Fasten the slides to the front pieces with screws. Countersink the heads of the screws so they will not be in the way of the hands when the vise is used. The two clamp screws should be about 1-1/2 in. in diameter. They can be purchased at a hardware store. A block should be fitted under the crosspiece to hold the nut for the end vise. After

[Ill.u.s.tration: Detail of the Bench]

you have the slides fitted, put them in place and bore the holes for the clamp screws.

The back board can now be fastened to the back with screws as shown in the top view. The bench is now complete, except for a couple of coats of oil which should be applied to give it a finish and preserve the wood. The amateur workman, as well as the pattern maker, will find this a very handy and serviceable bench for his workshop.

As the amateur workman does not always know just what tools he will need, a list is given which will answer for a general cla.s.s of work. This list can be added to as the workman becomes more proficient in his line and has need for other tools. Only the long run. If each tool is kept in a certain place, it can be easily found when wanted.

1 bench plane or jointer; 1 jack plane or smoother; 1 cross cut saw, 24 in.; 1 rip saw, 24 in.; 1 claw hammer; 1 set gimlets; 1 brace and set of bits; 2 screwdrivers, 3 and 6 in.; 1 countersink; 1 compa.s.s saw; 1 set chisels; 1 wood sc.r.a.per; 1 monkey wrench; 1 2-ft. rule; 1 marking gauge; 1 pair pliers; 1 nail set; 1 pair dividers; 1 pocket level; 1 6-in. try square; 1 oilstone; No.1, 2 and 00 sandpaper.

[Ill.u.s.tration: Workbench Complete]

** Repairing a Worn Knife Blade [228]

When the blade of a favorite pocket knife, after constant use, becomes like A, Fig. 1, it is more dangerous than

[Ill.u.s.tration: The Blade Is Cut Down]

useful. To cut down the already worn blade would leave only a stump, but if the blade is fastened in a vise and the point B filed off until it is like C, Fig. 2, the projecting point A, Fig.

1, will sink into the handle as shown at D, Fig. 3, and the knife will be given a new lease of usefulness. - --Contributed by James M. Kane, Doylestown, Pa.

** How to Make a Leather Spectacle Case [228]

The spectacle case shown in the accompanying ill.u.s.tration may be made of either calf or cow skin. The calf skin, being softer, will be easier to work, but will not make as rigid a case as the cow skin. If calf skin is to be used, secure a piece of modeling calf.

The extreme width of the case is 2-3/8 in. and the length 6-5/8 in. Two pieces will be required of this size. Put on the design before the two parts are sewed together. First draw the design on paper, then prepare the leather. Place the leather on a small non-absorbent surface, such as copper or bra.s.s, and moisten the back side with as much water as it will take and still not show on the face side. Turn the leather, lay the design on the face, and hold it in place while both the outline and decoration are traced on the surface with a pencil or some tool that will make a sharp line without tearing the paper.

After the outlines are traced, go over the indentations a second time so as to make them sharp and distinct. There are special modeling tools that can be purchased for this purpose, but a V-shaped nut pick, if smoothed with emery paper so that it will not cut the leather, will do just as well.

Take a stippling tool--if no such tool is at hand, a cup-pointed nail set will do--and stamp the background. It is intended that the full design shall be placed on the back and the same design placed on the front as far as the material will allow. Be careful in stamping not to pound so hard as to cut the leather. A little rubbing on the point with emery will take off the sharpness always found on a new tool.

Having prepared the two sides, they may be placed together and sewed around the edges.

If cow hide is preferred, the same