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Thread: Commutator refinishing?
04-05-2010, 09:32 AM #1
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?
04-05-2010, 01:39 PM #2
Your question should include what method you are using. Such as:
I have the armature chucked onto my lathe and....
04-05-2010, 02:23 PM #3
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.
04-05-2010, 02:28 PM #4
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.
04-05-2010, 06:48 PM #5
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.
04-05-2010, 06:59 PM #6
Thanks for the responses. Wish me luck!