Sorry, I didn't realize my Webmail was set to HTML.  Sending as Text:

I wiped the armature after I replaced the brushes, but I didn't do anything to 
remove carbon more aggressively (no stoning or anything). I also blew out all 
the carbon from shaping the brushes. That made a big mess! My brushes arrived 
with a square end, so I had to remove a fair amount of carbon. I used sandpaper 
wrapped around the armature as suggested by some DC motor maintenance web 
sites. It worked very quickly.

Mike

> On October 30, 2017 at 6:34 PM paul dove via EV <ev@lists.evdl.org> wrote:
> 
> 
> Did you clean the carbon off of the armature? If the build up is bad enough 
> you can have a frame short.
> 
> Sent from my iPhone
> 
> > On Oct 29, 2017, at 10:58 PM, Mike Nickerson via EV <ev@lists.evdl.org> 
> > wrote:
> > 
> > Hello everyone,
> > 
> > I've owned a long-time conversion for the last 7 years or so.  It is a
> > medium performance conversion with ThunderSky cells (still going!), Kelly
> > KDHD Series Controller and ADC FB1-4001-A series DC motor.  You can see its
> > history at:  www.evalbum.com/2778
> > 
> > I'm having a performance problem with the car at low speeds, and trying to
> > figure out whether it's the motor or the controller.  The symptoms are:
> > 
> >  -  Very sluggish acceleration at low motor speeds.
> >  -  Almost no voltage droop from the batteries while having the sluggish
> > acceleration (Low battery amps, as expected).
> >  -  Better acceleration at motor speeds above 3000 rpm.
> >  -  Good battery amps (60-70A) when driving at highway speeds.  Normal
> > performance when operating at battery voltage.
> > 
> > If I can get to highway speeds, the car does fine, but starting out in 1st
> > gear to get started is excruciating.  I think my 0-60 time is probably 50-60
> > seconds.  Without a clutch, it takes about 5 seconds between shifts for the
> > motor to spin down the 1000 rpm to match the transmission.  A little less if
> > I abuse the synchros.
> > 
> > From this, I'm sure that my amps, at low voltage, when the motor is turning
> > slowly, are limited for some reason.  I'm not sure if the controller isn't
> > providing the amps, or the motor isn't drawing them.  The controller is
> > supposedly rated for 1000A, but it's never done that.  However, it always
> > had enough before to accelerate a little better than the original gas car.
> > 
> > I did check the brushes and they were in sad shape.  The ADC motor has 4
> > pairs of brushes, on two windings.  On one winding, the left side on both
> > brushes was mostly shot.  On one brush, the copper braids were completely
> > gone.  On the second brush, the copper braids were nearly gone, just a few
> > strands of copper left.
> > 
> > The brushes have been replaced, shaped and run-in for about 20 hours now.
> > I'm running the motor at about 1500 rpm with no load (transmission connected
> > but out of gear).
> > 
> > Performance is a little better, but still not right.  I still have another
> > problem.
> > 
> > My thoughts:
> > 
> >  -  Is it possible that the brushes aren't full seated yet?  Could that
> > cause this kind of problem?
> >  -  What can I do to put an artificial load on the controller to see how
> > many motor amps it's providing?  
> >  -  I don't have instrumentation on the motor amps right now.  Is there an
> > easy way to do that?
> >  -  Is there an easy way to provide power to the motor while under load and
> > the car is moving?  I would have to go to a shop to have the motor pulled to
> > test it outside the car.
> >  -  Any other motor checks I should do?
> > 
> > Any other thoughts anyone has?  Any suggestions on the tests above to
> > isolate the problem?
> > 
> > Thanks in advance for any help.
> > 
> > Mike
> > 
> > 
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> > 
> 
> _______________________________________________
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>
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