PATTERN MAKING 



again with each alternate strip reversed, as shown in Fig. 9. In 



this way the tendency to warp is to a 



^ great extent corrected, each narrow strip 

 Fig. 9. being inclined to warp in an opposite 



direction to that of its neighbor. 



TOOLS. 



While many of the tools used by the pattern maker are identi- 

 cal with those used by the carpenter and cabinet maker, yet the 

 conditions that govern the construction of patterns for the mold- 

 ing of metals, together with the required accuracy in dimensions 

 and the methods of construction used to guard against warping, 

 distortion, and breaking, have very little in common with the 

 workmanship and methods of the carpenter, the wood turner or 

 the cabinet maker. 



Following is a descriptive list of the more essential tools used in 

 pattern making, accompanied with instructions in their use. 



HAND SAWS. 



Rip Saw and Crosscut Saw. Hand saws are of two kinds 

 rip and crosscut. The former, as the name indicates, is for 

 cutting with the grain, or lengthwise of the board to be sawed. In 

 Fig. 10 is illustrated a rip saw 



tl r~ ^ f-~ f~ ^, 



having 5| points to the inch, ^~~^ ^~ 



which will work rapidly and with 



ease in pine and other soft woods. 



If mahogany, cherry, or other hard 



wood is to be ripped, a six-point 



saw should be used. Rip saws 



should be filed with all the bevel 



on the back of the tooth, as shown 



at b in Fig. 10, the front or 



"throat" of the tooth being at right 



angles to, or "square" with, the g * 



tooth edge of the blade, as at a in the same figure. The position 



of the line c<l, whether perpendicular or slanting, is called the 



"hook" or "pitch" of the tooth. 



