Depth Gage for Saws IT is frequently nec essary to m ake a saw cut of uniform depth, and unless a special device is provided for the purpose the task is an extremely difcult one. The accompanying illustration shows a small gage which may be applied to any saw and may be adjusted thereon to prevent the saw from cutting deeper than desired. Two thin strips of wood of about the Depth gage for 1aws. length of the saw blade are fastened to a pair of arms secured to a block at the upper end. A thumb screw below this block may he tightened to clamp the two strips against the blade of the saw. These strips may be secured at any desired point on the blade, and thus provide an easily adjustable depth gage. A Sim ple Holder for Files THE principal difficulty of filing a smooth surface lies in the tendency to rock the file because the handle is located at the end. This tendency can be overcome to a large extent by fitting the file with a handle such as here illustrated. The handle may be made of a round iron rod, a quarter of an inch in diameter, with the ends heated and flattened, as shown. In one of the fattened ends two small holes should be drilled to receive the screws with which the device is secured to a block of oak three-fourths inch square and 2112 inches long. A hole should be drilled through the center of the wood to receive the shank of the file, and a thumb screw may be used as a set screw, to retain the file in the block. The rod may now '0 bent, as illustrated, to form a convenient handle, with the free flattened end bearing against the file surface. With an arrangement of this sort the pressure of the hand is better equalized and it will be found easier to file a perfectly smooth surface. Scaffold Dogs IT is always more difficult to make a scaffold with round timbers than with square timbers,; for the reason that there is no solid bearing offered in the former case. In order to make the scaffold secure special treatment is required. A simple device for hold- lng two round timbers together is pictured herewith. It consists of a U·shaped piece of round iron, with its free ends bent upward. This U-shaped piece is ftted round the upright timber, while the horizontal timber is supported in the cradle formed by the two ends. Before applying the hook, a dog is threaded upon it. This dog is provided with a tooth at each end, adapted to djg into the vertical timber and hold the hook at the desired position. The greater the weight on the hook the more frmly will the teth of the dog be embedded into the wood. At the same time, the hook may readily be removed when it is desired to take down the scafold. A Tapping Guide T HE engraving herewith shows a handy little device for tapping holes straight. The hole in the device is made large enough to take a half-inch tap and a bushing may be made to suit the bodies of taps from half inch to one-quarter. As soon as the point of the tap has entered the hole the operator can see if the tap is being held square with the work. After the tap has entered the hole far enough to guide itself the guide is removed so that the hole can be tapped out deeper. Ball-turning Device By H. D. Chapman THE ball -turning devic e illustrated in the accompanying drawings was designed to meet a special order for a large number of ball connections. A number of methods of doing the work were tried, but in every case the balls were not peI1fectly spherical and it was necessary to lap them in their seats. The fnal solution of the difculty was that shown in the drawings. The ball connection A (Fig. 1) was caught in the lathe chuck. The compound rest of the lathe was removed and a worm wheel SUbstituted. This had a pin in the center, which was fitted to the counterbore of the cross slide. The worm wheel was also supported by means of poles which fitted in a circular T-slot, though not so tightly as to prevent the wheel from revolving upon the center pivot. A tool post was mounted on the worm wheel, and .n this the tool was carried. The worm wheel which carried the tool was turned by a worm mounted on a shaft D, which was rotated by means of a belt 0 driven from the cone pulley of the lathe. The shaft D was connected to the pulley shaft by means of universal jOints, as shown clearly in Figs. 1 and 2. After a cut was taken the tool was advanced to a new position by a turn of the handle E. The balls turned in this manner were found to be perfectly true. Screw-driver Wrench and Tap Wrench By G. H. Ander T HE writer is freq uen tly called upon to repair the “reversers” of electric locomotives, and in order to do so it is necessary to remove screws which are so located as to be inaccessible to an ordinary screw driver. The screws are locked by denting the edges with a center punch so that they will not readily become unscrewed. Furthermore, they are so arranged that there is no way of securing a grip upon them with a small monkey wrench or a Stillson. Under these conditions, the writer found it necessary to make a special tool from a cotter pin about five or six inches long. The eye of the pin was flattened out, so as to receive the blade of a screw driver and the pin was bent to the shape shown in the illustration. In order to make the tool of further service, several notches were cut in the adjacent edges of the pin, so as to ft taps of diferent sizes. These notches were made with a fle, while the pin was split open for the purpose. A quarter-inch iron pipe was then ftted over the pin and holes were drilled in the pipe mating the notches in the pin. The result was a combination screw driver wrench and tap or reamer wrench. The drawing illustrates successive stages in the evolution of the tool. A Needle Drill By Philip Edelman T HE accompanying fgure illustrates a simple way to make small drills. Insert a common needle in a small chuck, and fle or break off the point. These homemade drills are excellent for all kinds of WOOd, and will cut thin lead and unglazed porcelain. The handy man will welcome them as an aid in starting small screws in baird wood and for many other uses. Workshop Notes Solder for Soft Metal -The following method will be found very handy for soldering soft metal at low temperature: Add three drops of mercury to each one-half ounce of solder. The solder will then fuse at a low temperature.-H. D. C. Drilling Compound. -In drilling tool steel such as dies, use a compound made of one pound common soda to four quarts of water, and one quart machine oil. Let it stand for about one-half hour, and it will be ready for use.-A. C. To Remove a Broken Amber Pipe Stem.-When an amber pipe stem is broken of, the amber part of the stem is very likely to stick in the bone sleeve, and if one attempts to take it out by force, the bone sleeve will probably be twisted out of the neck of the pipe. To overcome this difficulty, soak the broken stem and sleeve in alcohol. This will soften the amber stem slightly, and it can then easily be unscrewed from the sleve.-H. M. NICHOLS.
This article was originally published with the title "Suggestions for the Workshop" in Scientific American 105, 20, 433 (November 1911)