new question about motors

[hickston]

John really helped me out with skimming my motor, ie, it works again, but then ive had other advice about motors which is in conflict. and ppl dont need to skim motors...i look at the pits and everyone is skimming motors every race. ive 9 brushed motors now (and a couple of brushless)...can someone explain why the I need to skim every coupld of races?...yes i know they dont work if i dont, but why?

Ta
Stu

[Oscar]

Basically, running the motor you get "arcing" (sparks caused by trying to transfer elctricity from the brushes to the comm) which causes burning of the soft copper comm segments. As this occurs the comm can go very slightly out of round, causing brush bounce. This in turn adds to the arcing and creates a vicious circle. Eventually you get to the point where the comm is so badly burnt it is no longer possible to transfer electricity to it from the brushes, and the motor stops.
A light skim after every run or two keeps the comm round and the electrical contact clean, minimising arcing and ultimately prolonging the life of the motor. (Even though you remove material each skim, it still works out better to skim regularly because you remove far less each time)
This is a very simple overview of motor maintenance, ignoring many other factors, I could explain in more detail, but I hope this answers you question.
JOHN

[DCM]

I think it also depends on how hard you are on your motors and what brushes you use. I use Reedy767's mostly and find they are very kind on the comm and only ever skim at home but general get the comm stick out to remove any carbon buildup on the comm between runs. When I ran LRP brushes for a meeting last year, they were realy harsh on the comm and I ended up having to re-skim and brush every run.....

The reason why we skim a lot more now is that we put far more power through them pesky motors than we did even in '97.

[hickston]

omg, more complications to think about...wow, can we go back to 15 yrs ago and the opti mid please?

Thanks
Stu

[Chrislong]

Hickson, guess what......15yrs ago we still skimmed motors.... Not as regular as now, but we did. Although the Orion V2's are good for many runs between rebuilds...