Setup: ADC FB1-4001A, Curtis 1231C-8601, 44 TS-160 cells (141V nominal), 1993 mazda b2600 pickup.
I have a little over 1000 electric miles now. Everything is working great except that sometimes under heavy load (going up a hill) and high RPM (~3500) I will start to hear a buzzing sound. This is RPM dependent (vary RPM and the buzz freq changes). If I ease back on the throttle it stops. I have been wondering if this is some kind of arcing of brushes.
So today I removed and inspected 5 of the 8 brushes. I compare them to the wear patterns I found on this site:
http://www.gulfelectroquip.com/technical...commutator
Two of the brushes had about half the face pretty nice and smooth with some hairlining and the other half of the face (the trailing edge) was badly pitted and also looked like it had some copper particles embedded. I would say it was a combination of wear patterns S13 and S15 with a little bit of S21 (copper nesting).
The other three brushes looked better but also had the hairlining and a less than perfect trailing edge. They looked approx like the photo of S13 and no copper embedding.
For the commutator wear, I would say it looks like the drawing labelled "streaking". I have attempted to attach photos to this post.
I have been using this as my daily commuter vehicle, 12 miles round trip. I would say overall I have been pretty easy on it, except that I have one bad hill that I have to climb when I leave my office, while accelerating to highway speed. So for this hill I have to apply continuous full throttle for ~30-45 seconds.
When I got the motor, I did not do anything special to break it in. I have seen posts on here about running the motor for hours using a 12V battery to wear it in, and also to use a commutator cleaner stone to help seat the brushes.
So my question is now, what is the cause of this wear pattern, and if I now go through the "break in procedure" is that sufficient to fix it or will I need to do something else. I notice in the diagrams of the wear patters on the site I linked to, that they all say light spring pressure could be the cause. Do I need heavier spring pressure? If so, can I adjust the existing springs or buy new springs with more pressure? I did not see any apparent way to adjust spring pressure.
Thanks everyone for reading.
