ASSEMBLING THE ARMATURE CORE 



85 



the slot, and these will be points of weakness from the insulating 

 standpoint. 



Returning to a consideration of Figs. 84, 85, and 86, it will 

 be seen that temporary drifts are set upright in the slots to aid 

 in maintaining a true alignment. This is a point of great import- 

 ance, and it is the authors' opinion that a larger number of these 



FIG. 91. Assembling tlie Core of a Stationary Armature. Mavor & Coulsoii. 



temporary drifts could be employed to advantage. Thus in the 

 small armature of Fig. 84 the use of three or four drifts might 

 be desirable. This is because, although the drifts militate slightly 

 against rapid work in assembling the core, they ensure so much 

 more correct alignment as to greatly diminish the amount of 

 filing subsequently required at the sides of the slots, and they 

 may even make it practicable to altogether dispense with the 

 operation of filing the. sides of the slots of the assembled core. 



The drifts should be of steel, ground very smooth, and tapered 



