Mark, have you contacted Net Gain about this? Something doesn't sound
right about it. I would think that they would have run into this
problem by now. Maybe something didn't get built right with your motor.

David D. Nelson
http://evalbum.com/1328
http://www.levforum.com

Sent from my Nokia Lumia 920 Windows Phone 8 From: Mark Hanson
Sent: 5/13/2013 12:03
To: [email protected]
Subject: [EVDL] Brush uneven wearing, premature failure - fix
Hi,

I measured with a milli-ohm meter my Netgain-warfield-Impulse 9"
brushes at .5 milli-ohms and the cross bar that connects two in
parallel at .2 milli-ohms.  I calculated that the rear brush (since it
didn't go through the cross bar) was seeing about 85 more amps at 500A
motor current going up a hill (when i smell brush smoke).  I get about
3k miles out of the rear brushes but the front 4 brushes are at the
same length as new (with calipers).  I could just let the rear burn
down and then it would be forced to the front brushes - but the fix is
symetrical brush rigging like ADC has - same bar lengths from the
connection armature bolt to each brush.  When the first brush seats,
then it shunts and hogs all the current away from the other and the
front brush doesn't seat (until its' forced to by current).  I saw
only 1/2 contact area when I removed the front brushes after 3k miles
when the rears were worn down.

I could just look at it like changing oil every 3k miles or let the
others wear and go to 6k miles but my ADC's and prestolite's over the
years went to 100k miles before changing brushes.

Cheers,
mark in Roanoke
www.REEVA.info RE & EV's                                        
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