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 <firstname.lastname@example.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
> 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.
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