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 <firstname.lastname@example.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 <email@example.com> > > 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 > > > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)