Comm cutting

[highside]

I had around 15 runs on a P2K stock motor when I started to notice a serious decrease in performance. One of the local racers at my track said I need my commutator cut (which he did for me). This brought my motor back up to speed. So my question is this, is 15 runs typical of the time in between comm cuts? How often is a commutator cut necessary to maintain peak performance?
My motor gets cleaned after every race night (4 runs). Is this enough, or should I clean it more often?

[FilthyPierre]

Sounds about right. I get about the same out of my P2K. As long as you clean the comm after every meet (usually 5 races for me) it should go 3 maybe 4 meets without cutting. It also depends on your gearing but that's about what I get out of one cut. I generally don't suffer from loss of power though, so maybe you're geared too high.
You should inspect the colour of the comm after every meet too - if it starts to go blue, then it's getting too hot or burning, you should cut it then, and replace your brushes after cutting.

[Grizzbob]

Really, it depends on a number of things, like how you gear it, what car you use it in, how much voltage you give it(4 cells, 6 cells, etc.), & how the motor is set up(brushes & springs). Honestly, for the least amount of comm wear, it's usually better to cut it more often, like closer to every 4-6 runs. Doing it more often actually means removing less copper from the comm than if you do it less often(when brushes wear, they start to bounce, & that seriously accelerates comm wear)..... http://www.rccaraction.com/ubb/smile.gif

[prime]

I just can't wait for Novak to bring the brushless motor to market. Having to lathe your commutator after even 15 races is just not my idea of "the" right solution.

I'm no expert but it seems to me that by now (the year 2001 when cars should be flying!!) we ought to be using motors that need little tending.

My .02

[foo]

the year 2001 when cars should be flying?

Aren't they called planes? http://www.rccaraction.com/ubb/smile.gif

And you can race RC flying cars too.. It's called Pylon racing.. http://www.rccaraction.com/ubb/smile.gif

[prime]

No no, I meant flying cars as in the ones you actually sit in and drive. Ya know, like the Honda hover buggy or something.

It's interesting that the Hybrid cars are just hitting the general market. I had a chance to check out the Toyota Prius and it's interesting engineering.

Originally posted by foo:
the year 2001 when cars should be flying?

Aren't they called planes? http://www.rccaraction.com/ubb/smile.gif

And you can race RC flying cars too.. It's called Pylon racing.. http://www.rccaraction.com/ubb/smile.gif