86 



ARMATURE CONSTRUCTION 



at the upper ends. The edges should be rounded off so as to 

 permit of their being driven into place without marring the sides 

 of the slots. If only two drifts are used during assembling, as 

 indicated in Fig. 84, a third and fourth should be driven in 



s 



before the assembled discs are finally pressed up and secured in 

 their ultimate position on the spider. The drifts should not be 

 of more than 0*3 mm. less width than the punch with which the 

 slots were stamped out. The drifts should be considerably longer 

 than the finished core, and while building up the core, they should 



