1'ATTKKX MAKING 



ing the web. measure ; inch on each side: connect these points 

 from web to rim, and the arms will be 1| inches wide at web, and 

 1| inches at the rim. 



These lines are shown by the dotted lines in Fig. 174. The 

 width of the ends of the arms passing through the rim should be 

 about 2| inches, and the sides drawn parallel with the center line 

 of the arm, as shown for hand- wheel arms in Fig. 169. The radius 

 of the circle connecting the sides of the arms and the web, must 

 be such as to be tangent to the edges of the two connected arms, 

 and also tangent to the circle marking the diameter of the web. 



The smaller curve connecting the two edges of each arm with 

 the i mi must be of such radius as to be tangent to the arm and to 

 the 19-inch arcs which mark the inside of the rim (less inch). 

 All these lines are shown dotted in Fig. 174. The arms are now 

 ready for sawing to shape on the band or scroll saw, care being 

 taken to saw just outside of the lines so that each arm may retain 

 its full size and width. 



After sawing to shape, the edges must be dressed smooth and 

 free from all irregularities of the sawing. 



Next, from the web circle, taper the arms to | inch in thickness 

 at the extreme ends, care being taken to see that the taper of both 

 sides of the arms is uniform from the web circle to the rim. 



The shape of the arms should be elliptical or nearly so, and a 

 cross-section at any point in an arm may be obtained in the same 

 manner as described for the hand wheel shown in Figs. 170 and 171, 

 and the methods used for shaping and finishing are the same. 

 For building the rim, a wooden chuck 20^ inches in diameter will 

 be necessary. 



A board inch in thickness and having a bar 8 inches wide 

 and of the same thickness, well screwed to the back with wood 

 screws will be all that is necessary for a pulley of this size. To 

 the 8-inch bar, the iron face-plate of the lathe is screwed, and the 

 whole turned off true in the lathe, especially the face of the chuck 

 to which the first layer of segments is to be glued. 



Strips of heavy paper are often glued between the first layer 

 of segments and the face of the chuck, so that the rim and the 

 chuck may be easily separated when the rim is turned and finished. 

 The paper usually splits, allowing separation without injury to the 



