i86 MODERN BLACKSMITHING 



widest side next the chuck, and drill a hole in it the 

 same size as the hole in the saw. Turn off the end of 

 the collar to get it square. Prepare the other collar in 

 the same way. 



Now cut the shaft off the length wanted, and turn 

 one end to fit tightly into the balance wheel. Turn 

 off a place next to where the wheel comes for the bear- 

 ing or box. Now turn the shaft around and fit the 

 other end for the collars. The collar that goes on the 

 inside or side next the bearing should be shrunk on. 

 To do this leave the shaft about one sixty-fourth of an 

 inch larger than the hole in the collar, then heat the 

 collar to a red heat, and slip it onto the shaft. It 

 should not be driven very hard, or it will break in cool- 

 ing. Let it cool of its own accord. When nearly cool 

 it can be put into water and cooled off. 



The next step is to true up the inside of the collar, 

 leaving about one inch of surface to come against the 

 saw. Now turn the shaft down to the size wanted for 

 the thread, either i-inch or i^-inch, then with a cut- 

 off tool about ^-inch wide, cut in next the shoulder 

 the depth of the thread. If there is a die and tap handy 

 that will be the quickest way to cut the thread, but if 

 not handy then use the lathe. Now screw the nut on 

 and turn off the inside of the nut. For fitting the loose 

 collar there should be on hand a shaft about 14 or 16 

 inches long, turned a very little tapering ; then drive 

 the collar onto this shaft and finish it up. When ready 

 put this collar into place on the saw shaft and screw 

 the nut up tight. Now smooth off the outside of the 

 collars for loops. Cut the key seat in the shaft and 



