Originally Posted by tc4
We'll i think with my motor i run a gear ratio of 4.1 and when it comes off the track after a 6min race i can't touch it or i'll burn my finger. I have a heatsink and 3 fans blowing onto the motor aswell.
So i think the black stuff on my comm is from overheating it and the comm is actually burnt.
I need some sort of scraper.
dont scrape, you will damage the com. you could try a soft pencil eraser on the end of a pencil (dont know if this will work, but at least it is soft)
you are definately overgeared, forget gear ratios, as they are inherantly inaccurate as different cars have different internal gearbox ratios/ diff sizes, aim for a rollout of about 40mm as a starting point. (1 revolution of the motor moves the car forward 40mm, this method of working out gearing is independent of the cars internal ratios, lookup
www.gearchart.com)
that motor may be toast, but try running it in a jar of Brasso for 15 min on 1v, then in water for 15 min, then change the water and run for 15 min again, repeat until all the brasso residue is gone. re-lube bushes between each dunking.
Pete
