The Boy Mechanic Part 3

[Ill.u.s.tration: Warping the Aeroplane Wings]

shown in Fig. 2, the weight draws the lines to warp the plane so it will right itself automatically.

--Contributed by Louis J. Day, Floral Park, N. Y.

** Repairing Christmas-Tree Decorations [11]

Small gla.s.s ornaments for Christmas tree decorations are very easily broken on the line shown in the sketch. These can be easily repaired by inserting in the neck a piece of match, toothpick or splinter of wood and tying the hanging string to it.

[Ill.u.s.tration: Repaired Decoration]

** Homemade Scroll Saw [11]

A scroll saw, if once used, becomes indispensable in any home carpenter chest, yet it is safe to say that not one in ten contains it. A scroll saw is much more useful than a keyhole saw for sawing small and irregular holes, and many fancy knick-knacks, such as brackets, bookracks and shelves can be made with one.

A simple yet serviceable scroll saw frame can be made from a piece of cold-rolled steel rod, 3/32 or 1/4 in. in diameter, two 1/8-in.

machine screws, four washers and four square nuts. The rod should be 36 or 38 in. long, bent as shown in Fig. 1. Place one washer on each screw and put the screws through the eyelets, AA, then place other washers on and fasten in place by s.c.r.e.w.i.n.g one nut on each screw, clamping the washers against the frame as tightly as possible. The saw, which can be purchased at a local hardware store, is fastened between the clamping nut and another nut as shown in Fig. 2.

[Ill.u.s.tration: Frame Made of a Rod]

If two wing nuts having the same number and size of threads are available, use them in place of the outside nuts. They are easier to turn when inserting a saw blade in a hole or when removing broken blades.

--Contributed by W. A. Scranton, Detroit, Michigan.

** How to Make a Watch Fob [12]

The fixtures for the watch fob shown--half size--may be made of either bra.s.s, copper, or silver. Silver is the most desirable but, of course, the most expensive. The buckle is to be purchased. The connection is to be of leather of a color to harmonize with that of the fixtures. The body of the fob may be of leather of suitable color or of silk. Of the leathers, green and browns are the most popular, though almost any color may be obtained.

Make full size drawings of the outline and design of the fixtures.

With carbon paper trace these on the metal. Pierce the metal of the parts that are to be removed with a small hand drill to make a place for the leather or silk. With a small metal saw cut out these parts and smooth up the edges, rounding them slightly so they will not cut the leather or silk. Next cut out the outlines with the metal shears. File these edges, rounding and smoothing with emery paper. The best way of handling the decorative design is to etch it and, if copper or bra.s.s, treat it with color.

For etching, first cover the metal with black asphaltum varnish, on the back and all the parts that are not to be touched with the acid. In the design shown, the unshaded parts should not be etched and should, therefore, be covered the same as the back. Apply two coats, allowing each time to dry, after which immerse the metal in a solution prepared as follows: 3 parts water, 1 part nitric acid, 1 part sulphuric acid. Allow the metal to remain in this until the acid has eaten to a depth of 1/32 in., then remove it and clean in a turpentine bath, using a swab and an old stiff brush. The amount of time required to do the etching will depend upon the strength of the liquid, as well as the depth of etching desired.

[Ill.u.s.tration: Watch Fob]

For coloring silver, as well as bra.s.s and copper, cover the metal with a solution of the following: 1/2 pt. of water in which dissolve, after breaking up, five cents worth of sulphureted pota.s.sium. Put a teaspoonful of this into a tin with 2 qt. of water. Polish a piece of sc.r.a.p metal and dip it in the solution.

If it colors the metal red, it has the correct strength. Drying will cause this to change to purple. Rub off the highlights, leaving them the natural color of the metal and apply a coat of banana-oil lacquer.

** An Austrian Top [12]

All parts of the top are of wood and they are simple to make. The handle is a piece of pine, 5-1/4 in. long, 1-1/4 in. wide and 3/4 in. thick. A handle, 3/4 in. in diameter, is formed on one end, allowing only 1-1/4 in. of the other end to remain rectangular in shape. Bore a 3/4-in. hole in this end for the top. A 1/16-in.

hole is bored in the edge to enter the large hole as shown. The top can be cut from a broom handle or a round stick of hardwood.

[Ill.u.s.tration: Parts of the Top]

To spin the top, take a piece of stout cord about 2 ft. long, pa.s.s one end through the 1/16-in. hole and wind it on the small part of the top in the usual way, starting at the bottom and winding upward. When the shank is covered, set the top in the 3/4-in.

hole. Take hold of the handle with the left hand and the end of the cord with the right hand, give a good quick pull on the cord and the top will jump clear of the handle and spin vigorously.

--Contributed by J.F. Tholl, Ypsilanti, Michigan.

** Pockets for Spools of Thread [13]

A detachable pocket for holding thread when sewing is shown herewith. The dimensions may be varied to admit any number or size of spools. Each pocket is made to take a certain size spool, the end of the thread being run through the cloth front for obtaining the length for threading a needle. This will keep the thread from becoming tangled and enable it always to be readily drawn out to the required length.

--Contributed by Miss L. Alberta Norrell, Augusta, Ga.

[Ill.u.s.tration: Pockets for Thread]

** Cleaning Leather on Furniture [13]

Beat up the whites of three eggs carefully and use a piece of flannel to rub it well into the leather which will become clean and l.u.s.trous. For black leathers, some lampblack may be added and the mixture applied in the same way.

** A Baking Pan [13]

When making cookies, tarts or similar pastry, the housewife often wishes for something by which to lift the baked articles from the pan. The baking tray or pan shown in the sketch not only protects the hands from burns but allows the baked articles easily to slip from its surface. The pan is made from a piece of sheet iron slightly larger than the baking s.p.a.ce desired. Each end of the metal is cut so that a part may be turned up and into a roll to make handles for the pan.

[Ill.u.s.tration: Baking Pan without Sides]

A wire or small rod is placed between the handles as shown. This wire is fastened at each end and a loop made in the center. The pan can be removed from the oven by placing a stick through the loop and lifting it out without placing the hands inside the hot oven. The baking surface, having no sides, permits the baked articles to be slid off at each side with a knife or fork. --A. A.

Houghton, Northville, Mich.

** A Broom Holder [13]

[Ill.u.s.tration: Broom Holder]

A very simple and effective device for holding a broom when it is not in use is shown in the sketch. It is made of heavy wire and fastened to the wall with two screw eyes, the eyes forming bearings for the wire. The small turn on the end of the straight part is to hold the hook out far enough from the wall to make it easy to place the broom in the hook. The weight of the broom keeps it in position.

--Contributed by Irl Hicks, Centralia, Mo.

**Stringing Wires [13]

A string for drawing electric wires into bent fixtures can be easily inserted by rolling it into a small ball and blowing it through while holding one end.