The Boy Mechanic Part 112

--Contributed by L. L. Winans, Mexico, Mo.

** Reversing Small Battery Motor [405]

Make the switch out of a piece of slate (for the base) two strips of bra.s.s, a rubber strip and handle and some binding-posts from old dry batteries. Fasten the bra.s.s strips at 5 and 6, Fig. 1, so they can swing from 1 and 3 to 2

[Ill.u.s.tration: Switch]

and 4. Hold the bra.s.s strips apart by means of the hard rubber strip and screws. Do not let the screws come all the way through the rubber strip or you are liable to get a shock in case you should touch both screws simultaneously. Screw a rubber handle onto the rubber strip to move the lever back and forth with. Fig.

2 shows the arrangement of strips, handle, screws, etc., in detail. Fig. 3 is an end view of the same.

--Contributed by Eugene F. Tuttle, Jr., Newark, Ohio.

** Cleaning Bronze Bearings [405]

Bronze bearings may be cleaned with a solution of was.h.i.+ng powder and water run through the oil cups while the machine is running without any load. The solution, cutting out the dirt and grime, will come from the bearing very black. About 1 pt. of this mixture should be run through each bearing, then clean thoroughly with clear water.

** A Water Candlestick [406]

A gla.s.s of water makes a fine emergency candlestick. Weight one end of the candle with a nail just large enough to hold the candle in the water so that the water comes near its top edge, but does not touch the wick, and then light the candle.

It will burn until the last vestige of wick is gone and the flame will not flicker. The melted tallow that runs down but serves to hold the candle more stationary.

** How to File Soft Metals [406]

When filing soft metals, such as solder or babbitt metal, the file, after a few strokes, will become filled with metal, causing scratches on the surface being filed. The surface may be filed smooth, provided the file has been well oiled. The oil prevents the cutters from clogging and also allows the metal to yield easily. Oil the file every few minutes and use a card frequently in cleaning and the work will be smooth.

--Contributed by Jno. E. Ganaway, Paducah. Ky.

** To Make a Magazine Binder [406]

Get 1/2 yd. of cloth, one shoestring, a pasteboard box for covers, and some heavy paper. Cut the pasteboard into two covers, 1/4 in.

larger all around than the magazine, except at the back with which they should be even. Next cut a strip 1 in. wide off the back of each cover. Place the covers on the cloth, Fig. 1, with the back edges 1/4 in. farther apart than the thickness of the volume to be bound. Cut the cloth around the covers, leaving 1-1/2 in. margin.

Paste the cloth on the covers as they lay, and turn over the 1-1/2 in. margin, pasting down smoothly. Cut a piece of stiff paper to fit and paste on the back. Take a piece of cloth as wide as the cover, and long enough to extend over the back and 1-1/2 in.

[Ill.u.s.tration: Plan of Magazine Binder]

Beyond each "strip." Paste on to hold all together. Two pieces of paper the exact size of the magazine, pasted on the inside of each cover protects the edges of the cloth, and adds to the appearance.

Let dry slowly.

[Ill.u.s.tration: Magazine Binder Complete]

With backs and edges of magazines even, place in a vise and set up tight allowing 3/4 in. from back to show above the vise. Bore three 3/16-in. holes 1/2 in. from the back, one in the middle, the other two 1-1/2 in. from each end. Make corresponding holes in the strips of the binder and use the shoestring to complete as in Fig.

2.

** Temporary Spline [406]

A piece of wire solder makes a good temporary spline for the draftsman.

** A Library Set in Pyro-Carving [407]

By HELEN WESTINGHOUSE

The mult.i.tude of indifferently executed small articles which followed the introduction of pyrography is beginning to disappear.

People are considering the art more seriously and

[Ill.u.s.tration: Table and Seat Decorated in Pyro-Carving]

applying it to more dignified uses. Pyro-carving is one of the new methods of decorating furniture which is both beautiful and practical, two qualities which do not always go together.

The library set ill.u.s.trated consists of a table, 30 to 50 in., with two benches, 14 in. wide, of the same length. The supports are made of selected white pine, which must be absolutely free from pitch. The pine is soft enough to work easily with the point and stands wear much better than ba.s.swood. The tops and braces are made of curly fir. All of the material must be 2-in. lumber, which dresses to about 1-1/2 in. All surfaces, except the faces of the supports, are given a well rubbed coat of oil with a little burnt umber, the stain to be applied directly to the wood without a filler.

On the outside of the supports the design is drawn in with pencil, the background is then cut out smoothly with a chisel to the depth of an eighth of an inch, leaving the decoration in relief. It is then burned deeply, the background in straight flat strokes, the outlines having the effect of a sloping, dark edge. The shadows are burned in as deeply as possible and the shading is put in with the flat of the point.

A wax or eggsh.e.l.l oil-varnish finish is most suitable for this set, but any other finish may be applied, as the builder may desire, to make it harmonize with other furnis.h.i.+ngs.

** Cleaning Bra.s.s [407]

Small bra.s.s castings can be cleaned by heating them slightly and then dipping them in a solution of sal ammoniac. The pieces will come out as bright and clean as if new. This cleaning process is the same as that used in cleaning a soldering iron.

** A Phoneidoscope [407]

The phoneidoscope has many and varied forms, but the simplest can be made by bending the forefinger and thumb so as to form a circle and then drawing a soap film across the opening. This is done in a manner similar to the blowing of soap bubbles. The angle with the direction of the light may be readily adjusted by turning the wrist, a motion of the elbow alters the distance from the mouth and the tension of the film can be regulated by moving the thumb and forefinger. Singing or speaking at the film when under proper tension will cause beautiful figures to appear, which may be reflected from the film directly on the screen.

--Contributed by Robt. E. Bradley, Winchester, Ma.s.s.

** A Home-Made Yankee Bobsled [408]

A good coasting sled, which I call a Yankee bob, can be made from two hardwood barrel staves, two pieces of

[Ill.u.s.tration: Runners Made of Barrel Staves]

2 by 6-in. pine, a piece of hardwood for the rudder and a few pieces of boards. The 2 by 6-in. pieces should be a little longer than one-third the length of the staves, and each piece cut tapering from the widest part, 6 in., down to 2 in., and then fastened to the staves with large wood screws as shown in Fig. 1.

Boards 1 in. thick are nailed on top of the pieces for a seat and to hold the runners together. The boards should be of such a length as to make the runners about 18 in. apart.