The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck

The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck


Скачать книгу
12 in. by 2 1/2 in. by 1 1/2 in., and the sides S 15 in. by 6 in. by 1 1/2 in. These sides are fixed to the jaws by means of two small tenons, as shown by dotted lines, being glued to keep them in position. Fig. 269 shows a handy and cheap vice, which can be fixed to any support by means of a screw-bolt and fly-nut passing through it. The movable jaw is acted upon by a similar bolt and fly-nut. Figs. 270 and 271 show an improved saw vice, differing from ordinary vices only in the method of tightening up the jaws; Figs. 272 and 273 show plan and elevation of eccentric clamp with rod and nuts. The rod is of 1/4-in. round iron, screwed at each end (mild steel would be more suitable), the bends being made when the iron is heated red hot. This clamp must be shaped out, and the protuberant part where it will tighten on the stock should be smooth and true. Two 5/16-in. holes, which will be 6 1/2 in. down, are bored through both uprights to accommodate the ends of the rod, and collars may be let in flush at the back to tighten the nuts against. When the nuts are adjusted, a saw is instantly clamped by pressing the handle down as shown in Figs. 270 and 271. To release the saw, pull up the handle of the eccentric clamp or lever. The position of the rod hole is as shown in the illustrations. It will add to the grip of the jaws to make the uprights slightly curved outwards in the middle, and a 2 1/2-in. butt hinge will complete the vice. A strip of vulcanised rubber or leather fastened along the top inside edge of jaws will improve the grip.

      Figs. 267 and 268.—Saw Vice.

image

      Fig. 269.—Saw Vice.

image

      Figs. 270 and 271.—Improved Saw Vice.

image

      Figs. 272 and 273.—Clamp of Improved Vice.

      Fig. 274.—Saw Bench.

      SAW BENCH.

      Fig. 274 represents a handy bench in which to fix a saw. The treadle-like frame at the bottom, when pressed upon by the feet, acts through the two upper side pieces as fulcra upon the two gripping jaws.

      PORTABLE SAW VICE AND BENCH.

      A portable vice for use when sharpening hand saws is shown by Fig. 275. It consists, practically, of a low stool, with one leg fixed at the extreme end, and continued upwards to a height suitable for the operator. The latter sits straddle-wise on the stool. The seat should be strongly mortised through the long leg, and be glued and wedged; and the back or short leg should be similarly mortised through the seat, unless the drawer shown—which is convenient for holding files—is omitted, when, as is frequently the case, the short leg may be hinged to fold up under the seat. In the latter case an iron stay—two would be better—must be provided to hold the leg rigid whilst the “horse” is in use. The movable jaw is simply a piece of wood hinged at the bottom to the long leg, and cramped up tightly against the other jaw by a fly-nut working on a screw, or by a screw as shown in the illustration. In order to keep the vice jaws from warping, strips of oak, mahogany, or other hardwood should be screwed on the inside surface of each, as shown, and these, again, may be covered with sheet lead. As the wood of which the jaws are made will be almost sure to curve somewhat as it gets dry, care should be taken that the growth marks or annular rings take a course from the outside of each jaw towards the inside; the jaws will then have a tendency to become concave on their faces, and will at each end tightly grip a saw placed between them, and the tightening-up process will tend towards bringing together the central part of the jaw faces. If the wood is placed so that the annular rings have the opposite direction, the jaws will, in course of time, become convex, and difficulty will be experienced in holding a saw firmly.

image

      Fig. 275.—Portable Saw Vice.

image

      Fig. 276.—Triangular Saw File.

      Fig. 277.—Double-ended Saw File and Handle.

image

      Fig. 278.—File for American Cross-cut Saws.

      SAW FILES.

      The triangular file shown by Fig. 276 is the one usually adopted in sharpening English hand saws. Its size varies with that of the saw for which it is required. It is economical to use a double-ended saw file as shown by Fig. 277; when one end has become dull, the file may be reversed, and the other end used. For sharpening American cross-cut saws the file shown by Fig. 278 is used, and for American rip saws that shown by Fig. 279. Saw files are generally cut in three degrees of fineness, a second cut or smooth-cut file being best for sharpening a hand saw. A file for sharpening saws must be of the very best quality. See that the teeth are cut perfectly even, and that the colour of the file is uniform. If it is of whitey-grey colour throughout, it shows that the temper is uniform; but if it is mottled, the temper probably is uneven. For levelling down or topping saw teeth preparatory to sharpening, a flat file (Fig. 280) will be necessary.

      Fig. 279.—File for American Rip Saws.

      Fig. 280.—File for Topping Saw Teeth.

      ASCERTAINING ANGLE OF SAW TEETH.

      To ascertain the angle of a saw tooth, draw a semicircle on cardboard, and mark off degrees to form a protractor (see Fig. 281). Place a 2-ft. rule on the horizontal line, and open the rule to the angle required. Draw a line D (Fig. 282) on the saw-plate; or, if the saw to be tested is a circular saw, place one part of the rule on the top of the bench table, and move the other part of the rule until it is in a line with the point of the centre tooth. If the front of the tooth corresponds with the bevel of the rule, the rake or lead is correct. If the circular saw is a large


Скачать книгу