Originally Posted by RicksterRC
I happen to have pinions from both motors here in front of me...
Under 8x magnification, they are clearly differenent.
On the Bravo SX pinion, the teeth and gaps look about the same width as each other.
Tooth/gap ratio about 50/50.
It looks as if two pinions would mesh with one another nicely.
The teeth on the V911 pinion are "thicker" and the gap between "thinner" than the Bravo SX pinion.
Tooth/Gap ratio maybe 60/30.
A V911 pinion would definitely not mesh well with another V911 pinion.
I examined the V911 vs SP Delrin gear and the tooth profiles look virtually identical to me.
There might be better moulding on the SP (less flash), but I don't think the tooth profile contributes anything.
Looking at the pinions in the copters, I can see that the V911 motors don't mesh as well as the (one) Bravo that I have.
On my Blue copter (probably the one with the most hours), the pinion of the original motor (currently dead and awaiting replacement) is noticeably worn - as if it wasn't happy.
Holding both gears and v911 motor with my fingers and running the v911 motor over both gears, the Delrin is definitely rougher. Running the Bravo SX (and gw9958 with 8 teeth) motor over both gears is smooth. In the last week, two v911 motors died using Delrin gears. I installed a spare v911 motor I had from the copter the Bravo SX is in and reverted to the stock white main gear. I was going to try the gw9958 but man was it a tight fit. I'll hold off doing that as a last resort.
Please report back on the SP270 motor. If I remember correctly, that's a very tight fit as well, but I'm just going from memory of something I think I may have possibly read.....maybe....possibly