What's new
What's new

Commutator refinishing?

jonfritch

Aluminum
Joined
Jul 23, 2006
Location
Little Rock Arkansas US of A
:angry: I know I'm just missing something I should already know, but I'm having one heck of a time getting a smooth finish on the copper armature segments of a series wound motor with brushes. I get bumps and boogers instead of smoothness. So, all you great guys, how should I sharpen my HS tool to cut copper?:angry:
 
Your question should include what method you are using. Such as:

I have the armature chucked onto my lathe and....
 
This is the tool I use, hand ground and honed sharp. It is narrow because some armatures I do have a balance ring right up next to the commutator.
 

Attachments

  • IMG_0620.jpg
    IMG_0620.jpg
    21 KB · Views: 235
  • IMG_0621.jpg
    IMG_0621.jpg
    18.1 KB · Views: 245
  • IMG_0622.jpg
    IMG_0622.jpg
    16.5 KB · Views: 216
I worked at General Electric for almost 25 years and finished comms from 8 inch to 38 inch. We used a diamond finishing tool. About 25 degrees and slow feed. Small radius on tip. Try the same for HSS. The worst part was deburring after finishing the comm.
 
I did this in the 60's,and 70's.

The radiused tool shown will work the best and give you a finish that won't need to be touched after turning.

Spin it fast, like it was alluminum. slow feed. no coolant or oil. light cuts.

I hated cleaning out (relieving) the mica without screwing up the copper.
 








 
Back
Top