Hi , Roland Wench said that the brush bars (feeding the brush mounting screws) if not exactly the same length will cause the rear brushes to wear faster since there is about 10 micro-ohms more to the front brushes (the rears shunt out or carry most of the current). I thought about snipping one of the 4 wires on the rear brushes to force more current to the front one’s but that’s more of a commitment so I crossed the wires. I’m still getting arcing on the rear brushes though but I’ll try it that way for a week and see with my calipers if the distance from brush rear to holder which is now .30” shrinks more than the other side, then I’ll swap the brushes (but that’s more work). It’s a positive feedback loop – when the rear brushes carry more current & get shorter then their micro-ohms resistance decreases so they carry more current etc and accelerates the wearing. Chip sent a photo of an 8" ADC motor brush rigging and the bus bars feeding the dual brushes are uniform, same length. The Netgain/warfield 9" Impulse are not, the front brushes have another two inches of extra bus-bar to go through so they are not "tuned" to the same micro-ohms thus the rear brushes are shunting more current. Thanks Roland for this good find! Have a renewable energy day, Mark Mark E. Hanson184 Vista LaneFincastle, VA 24090540-473-1248 phone & FAXwww.REEVA.info - community service RE & EV'sA DIY project club -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130508/cc45a18e/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)
