132 



PATTERN MAKING 



of the wheel with accuracy, the teeth laid out on the two sides 

 will be true and perpendicular to each other, a spacing line 

 forming the exact center of each tooth, and for this reason these 

 lines should always be very light but sharp and dearly defined. 



For convenience in cutting and paring, a second series of 

 lines should now be drawn across the face of each block connecting 

 the extreme ends of the lines which describe the shape of the tooth 

 on each end of the block. Should the wheel be small and 

 within the capacity of the band saw, all superfluous wood may 

 easily be removed from between the teeth. 



If the band saw is sharp 

 and evenly set, and the operator 

 skillful, the teeth may be sawed 

 so as to need but very slight 

 correction with the paring chisel 

 and gouge. 



As the hubs usually project 

 beyond the rim on each side of the 

 wheel, they should be left loose 

 and removed before placing the 

 wheel on the saw table. 



Fig. 243. 



For large wheels and heavier teeth, each tooth block should be 

 unscrewed and removed, one at a time, and planed to the lines 

 marked on its ends and face, after which it is returned 1<> its place 

 before a second one is taken off. This is continued until all the 

 teeth are shaped, when it will be necessary only to construct fillets 

 at the base of the teeth, and also to work each space down to the 

 irholc (h'plh circle, the circle having been drawn for this purpose, 

 and also as a guide, for bringing all tooth spaces to the same 

 depth. 



Small gears, or pinions as they are called, are usually made 

 with a solid web instead of arms, and are glued up in solid blocks 

 of end wood, the grain of the entire block running parallel with the 

 face, of the teeth. Such an end wood pinion is shown in Fig. 243. 

 It is turned and the gear laid out and cut in the same way as 

 described for the larger wheels, except that the teeth are not glued 

 on but cutout in the solid disc. In the const ruction shown in 

 Fig. 241, the teeth, not being screwed on. must he nailed with brads. 



