Page:Popular Science Monthly Volume 89.djvu/135

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An All -Steel Screwdriver IE scre\vtlri\ (.T to be (lescribfd is constructed entirely of steel and while feeling heavy at first will be found to be very well balanced and able to stand hard usage. If the blade is broken it can be easily repaired or re- placed or different sized blades may be used.

The whole tool, including the fluting of the handle, was made on a small back-geared lathe with a hand-fed car- riage.

A 5" length of i>^" cold-rolled steel shaft was cut off and a 3/8" hole 3" deep bored in the center of it to take the blade. The handle was then roughed out nearly to the finished dimensions and a light finishing cut taken all o\er it at high speed.

The handle was fluted as follows: The circumference of the large end was

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��A Buck-Saw Attachment i ordinary' i)uck-sa\v trainc has a tendency to cramp the upper

hand when sawing. To

eliminate this, bore a K in. hole through the top part of the frame just

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fi Croore^ A screwdriver made entirely of steel

divided and punch-marked into twelve equal parts. Then a hole was drilled and tapped for a la," set-screw in the small part of the handle, as shown in the drawing, and a length of 3/8" rod set in and countersunk for the set-screw. The outside end of this rod was held in the lathe-chuck, the large end of the handle being held in the back-center. A steel lathe-tool with a small rounded end, was placed in the tool-post turned over on its side; the lathe-chuck was kept from turning by locking the back- gears, and then each groove was cut by moving the carriage along by hand and taking a succession of light cuts until the groove was of the required depth.

The blade was made of a piece of ^'g" tool steel with the tip end hardened and was held in the handle by means of the y^" set-screw, countersunk about J^". A set of blades could be made of differ- ent lengths or with tips of different widths.

��A simple peg makes the task of sawing wood a little less strenuous

below the tightening wire. Cut off a piece of an old broom handle 4 ins. long and drive it through this hole half pro- jecting on each side. By gripping this pin with two fingers on one side and two other fingers on the other side, with the saw frame between, the wrist will not be twisted. — W. J. Albin.

How to Etch Glass

W.^RIM a piece of glass care- fully; if heated too rapidly the glass will crack. Rub paraffin or beeswax over the warm sur- face of the glass. With a blunt in- strument print the desired wording. To some fluorspar (calcium fluoride) placet! in a metal ilish, add enough concentrated sulphuric acid to moisten the powder. Place the glass, with the marked side down, over the metal dish containing the above chem- icals and leave it over night. In the morning, scrape the paraffin off and the desired words will be etched on the glass.

���The fluoride bath

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