PATTERN MAKING 



described for the hand-wheel pattern. The projecting ends of the 

 arms are cut off and shaped to form a part of the outside of the 

 rim. The internal curves of the arms at the inside of the rim are 

 also filed and shaped down so as to form true curves without cusps 

 or irregularities. The hub is next glued up in cross-layers as 

 described in Fig. 172, turned out, and glued centrally on each side 

 of the arms. 



The pulley being intended for a If-inch shaft, the core prints 

 x and y, Fig. 173, should be 1^ inches in diameter, which will give 

 ^ inch of metal for boring out to fit the shaft. The two core prints 

 (Fig. 175) should be turned separate from the hubs, and loosely 



attached with a pin f inch 

 in diameter, and inch long, 

 into each half hub, so that 

 other sizes may be used for 

 larger or smaller shafts. The 

 two half hubs are often made 

 loose so that they may be 



<\J 



Fig. 175. 



changed for larger or smaller hubs as may be required for different 

 sizes of shafts. In such cases they are attached centrally to the 

 arms as described for the core prints. 



A second method in the construction of such special pulleys 

 is as follows: 



The half rim having been glued up as described, the inxidc 

 only of this half is turned to the required dimensions and draft, 

 sand-papered, and finished, the width of the half rim being made in 

 this case -f^ inch less than the half of the face of the completed 

 pattern. The arms are carefully centered and glued to this half 

 rim; and the intervening spaces between the ends of the arms are 

 filled in with six segments y inch in thickness, which, when glurd 

 and dry, are planed, not turned, true and even with the surface of 

 the arms. 



A layer of segments of the regular thickness is fitted and 

 glued on over the arms, and layer after layer continued until the 

 full width of the face of the pattern is reached, thus building Un- 

 arms directly into their place in the pattern as the rim is glued up. 

 In turning and finishing, care must V taken not to strike the arms 

 with the tools while turning out the inside of 1 lie outer half of t lie rim. 



