Fig. 2722.
The cracks that are found in timber are termed shakes; thus in [Fig. 2720] the black lines represent what are called heart shakes, while those in [Fig. 2721], being wider, are termed star shakes. When the shakes are circular, as in [Fig. 2722], they are called cup shakes.
Many of the tools used by the pattern-maker have been described in connection with hand turning, hand boring tools, lathe tools, &c., and therefore need no further reference.
Planes.—For roughing out the work the jack plane is employed, varying in size from 14 inches long with a cutter knife or blade 2 inches wide, to 27 long with a blade 21⁄4 inches wide, and as its purpose is to make a flat surface, it is preferable that it be as long as the work will conveniently permit. The jack plane is followed by the fore plane, the truing, or trying plane, which varies in size from about 18 inches long with a blade 21⁄8 inches wide, to 20 inches long with a cutter or blade 23⁄8 inches wide. When the fore plane is made longer, as for planing long joints, it is termed a jointer plane, the length being as much as 30 inches and the blade 25⁄8 inches wide.
The smoothing plane varies from about 5 inches long with a blade 11⁄2 inches wide, to 10 inches long with a blade 23⁄8 inches wide. Smoothing planes are, as the name implies, used to simply smoothen the work surface after it has been trued.
The angle of the plane blade to the sole of the plane is for ordinarily soft wood 45°, but 50° or 55° may be used for very hard woods.
Fig. 2723.