Mark, Why is this different on your motor than tens of thousands of other motors in the field without the problem? Your conclusions are not supported by the vast population of properly functioning motors using the identical brush rigging. Something else is causing the problem.
You haven't even considered contamination that I am aware. Silicone can attack the brush and cause similar behavior, ie. non-filming and rapid wear. There are a lot of other possibilities. Jeff M ________________________________ From: Mark Hanson <[email protected]> To: "[email protected]" <[email protected]> Sent: Thursday, May 16, 2013 7:49 AM Subject: [EVDL] Uneven brush wear followup Thanks Roland & Lee, That makes sense, when I get a chance I'll figure out how to make the brush rigging even like ADC. I moved the rear shorter brushes to the front and they're still wearing faster cause they seated first and the long one's never completely seated (see about 1/2 contact area under them - same length as new). I noticed when I swapped running locations that the comm is bright copper under the shorter one's that are carrying most of the current and a light brown under the longer one's that are not. This color moves with the brushes - and the front/rear comm is equally smooth. That's why I think Roland & Lee are correct, that symetrical brush rigging will start the seating process evenly and keep it so throughout the life. It's a positive feedback loop, once one brush (rear) group starts getting shorter and drawing more current then it hads a snowball effect and keeps doing it even later when swapped to the front positions (is 1/4" differential). I think Roland's brush rotatin g works because they haven't burned down more than 1/4" differential (or .2 milli-ohm differential - when I see the snowball effect go). Best regards, mark Hello Mark, As I said before, the rear brushes are shunting the front brushes. The rear brushes are closer to the armature circuit connections to the communtator bars, thus a more resistance path to the front brushes. This is normal in the three motors that I am using in my EV. I run three types of motors in my EV. One is a WarP-9, a WarP-11 and a GE-11 which the WarP-11 motor frame is the same frame as a GE-11. I have run the GE motor for 10 years where the rear brushes worn down 1/4 of the original length of 2 inches. The front brushes only worn down about 1/8 inch. Every 10 years as per GE maintenance, pull the motor, check spring tension, resistance tests and check the communtator surface. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130516/099731bd/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130516/595c5771/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
