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)
