Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 25

A prominent fault of shooting-boards, as generally constructed, is that the plane used on the board loses its edge very quickly, especially on thin wood and when dealing with material of uniform thickness. The reason for this is that only a small part of the edge of the plane-iron is in use, and the same small portion constantly. All who have used edged tools know that an oblique movement cuts sweeter than a direct and forward movement; the edge employed in the actual cutting having a greater width than the shaving removed. The same thing is observable in a rebate plane. A skew-mouth plane not only keeps better up to its work, but the shaving seems to be more smoothly removed, and the cut surface has a better finish. In order to obtain these advantages, the shooting-board shown by Fig. 54 is offered. The planes used on a shooting-board should be sharpened squarely with a straight cutting edge; this is very important when shooting mitres, especially picture frames. If the iron of the plane is so sharpened, the distance between the surfaces on which rest the plane and the material worked upon need nor exceed 3/8 in.; nearly the whole width of the plane-iron is then available for use. Supposing that a shooting-board is required to take advantage of the oblique cut and the employment of a larger part of the edge, the wood operated on may be taken to be not more than 3/4 in. thick (for thicker work is more independent of a shooting-board): then the difference in level at the two ends of the shooting-board may be possibly as much as 1 1/2 in. This board (Fig. 54) is not drawn to scale, but may be made of any size suitable for the purpose for which the maker intends it, and it might be improved by making the incline adjustable with a pair of thumbscrews, or perhaps, preferably, by hingeing the two parts together at one end and employing a movable wedge and bolts at the other end for the purpose of adjustment.

Fig. 46.—Outside Callipers.

Fig. 47.—Inside Callipers.

Fig. 48.—Shooting Board.

Figs. 49 and 50.—Elevation and Plan of Improved Shooting Board.