# Brush Arcing! motor break-in amp limit?



## ruckus (Apr 15, 2009)

Hello,
The 37 Jag is now up and running! First test run was about 65 miles.  Overall the thing is a blast to drive, but some issues are showing up and I could use some help. 

Specs:
30 Thundersky LFP260 (96v nominal), 780 amps continuous, 2600 amps momentary, 25kw pack.
ADC 8" 203-04-4001a motor
Zilla Z1K controller
Chassis is 69 vw with fiberglass Jag body, Very light.

The car drives great, but if the controller is set above 500 amps the motor makes a grinding noise at full throttle. I assume this is brush arcing. I removed a brush and it is smooth over about 70-80%. Tiny pits are visible on one side and there are more grooves than I would like to see. The commutator has a flat black look with some grooving. After doing some searching I find a few mentions of seating the brushes at 12v for quite a while before use to build a "glaze". I also hear of commutator "stones". The motor came with zero documentation and I find it hard to believe that other users don't just jump in their forklift and go. Maybe a sticky on motor break in is needed.

At this point, can these brushes/commutator be used as is? The pits are very tiny, almost invisible. If the amps are kept low will they seat over time with mellow use? Should I run it on jack-stands for a day or two? Are there better brushes that can handle 700-1000 amps?

The other issue with the motor is a vibration at 3-4000 rpm. While I realize this could be in the coupler/flywheel/clutch, after the first drive a mysterious chunk of gunk fell out of the motor. I read another user had "balancing putty" come loose to produce a motor vibration. His motor was replaced under warranty. Should I send the chunk off to adc? Is this common? 

Any help or suggestions appreciated.


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## major (Apr 4, 2008)

ruckus said:


> The other issue with the motor is a vibration at 3-4000 rpm. While I realize this could be in the coupler/flywheel/clutch, after the first drive a mysterious chunk of gunk fell out of the motor. I read another user had "balancing putty" come loose to produce a motor vibration. His motor was replaced under warranty. Should I send the chunk off to adc? Is this common?
> 
> Any help or suggestions appreciated.


Hi ruck,

Yep, you better call the place where you bought the motor. If that is balance putty, or if the motor is otherwise out of balance, it needs to be corrected. If they don't help, find a local motor repair shop.

You should be able to find old posts of mine about proper motor break-in. Search for brush seating, or break in, comm film, commutator patina, etc. 

Regards,

major


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## ruckus (Apr 15, 2009)

major said:


> Hi ruck,
> 
> Yep, you better call the place where you bought the motor. If that is balance putty, or if the motor is otherwise out of balance, it needs to be corrected. If they don't help, find a local motor repair shop.
> 
> ...


Thanks for the search terms. Those help a lot.

We bought the motor from evcomponents which is now kinda a 4-letter word.  Perhaps ADC can help.

On the upside, we were among the lucky few who received the final shipment of Zillas with the "by evcomponents" writing on them.


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