zagibond

Thanks again for the very informative explanation. Instead of re-inventing the wheel, I will follow your lead since you aparently have done your homework. Incidently, my brush arms break off way before they touch the commutator.
So for a 3DX what is the best available brushless? I can't get my hands on a razor, nor a Himax 2015-4100.
Do brushless motors wear out? I have read that the magnets eventually loose their polarity?