129 



receive these ends art; now cut into this half rim, and the arms fitted 

 and glued in place but not so tightly as to strain the rim and 

 cause it to spring after it is removed from the chuck. The 

 remaining courses for the rim are now fitted and glued on, and the 

 rim turned and finished to the required size and shape. 



The face should be glue-sized to prepare it for the blocks which 

 are to form the teeth of the gear. 



After sizing and removing the raised grain of the wood, the 

 periphery of the wheel must be spaced for the required number 



Fig. 239. 



Fig. 241. 



Fig. 240. 



of teeth. With a try square and very sharp awl draw lines through 

 the points obtained by the spacing as shown in Fig. 240. Should 

 the teeth be of moderate size, say 3 pitch or less, the tooth blocks 

 should be glued on sc as to meet each other on the rim of the 

 wheel as shown in Fig. 241. 



Each block must be so fitted as to reach only from line to line, 

 Fig. 240, care being taken to have each block parallel to, and 

 coincide with its own line, Teaching exactly to the line. When 

 all the blocks are placed and glued, the wheel is returned to the 

 lathe and the periphery turned off straight and to the required 

 diameter for the addendum, or extreme ends of the teeth. The 

 ends of the blocks are also turned even with the edge of the wheel rim, 



