612 



Popular Science Monthly 



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MOTOR CONN. 



COMPLETE MOTOR 



FIG. 9 



Entire details of all the parts necessary in the construction of a universal motor that is 

 especially adapted to drive a fan on the ordinary vacuum cleaner used for household purposes 



7/16 in. in diameter, rough, to be turned 

 as shown in Fig. 3. The threads may be 

 cut in the lathe at the same time that the 

 shaft is being turned. Now bore a %-m. 

 hole through the center of the stack of 90 

 2 by 2-in. iron and then varnish the plates. 

 When dry slip them on the shaft and 

 clamp them between the two iron washers. 

 Do not tighten the nuts too much or 

 stripped threads will result. Now proceed 

 to turn the armature to a diameter of 

 1% in. Be very careful not to feed the 

 lathe tool too fast or it will cause the 



plates to turn on the shaft. Now lay out 

 the eleven slots as shown in Fig. 4. The 

 drilling should be done in a drill-press and 

 the armature set in a jig so that the shaft 

 will be parallel to the drill. Great care 

 should be used to get the slots absolutely 

 parallel to the shaft and accurately spaced. 

 With a hack saw cut through the i/i6in. 

 of metal on the diameter of the laminae 

 and smooth up with a small file. 



The shaft can now be finished to 34 m - 

 in diameter. This should not be done 

 earlier because it would twist out of shape 



