Pinion Modulus explained


Matching the modulus of your pinion ( the gear on your motor ) to the helicopter main gear is vital to achieve efficient transfer of power and minimum wear on the gears.

But what is modulus and if you don't know what it is for a random pinion you found in the back of a drawer, how do you measure it?

mCPX HP03S upgrade with 8 and 9T pinions - test data

After recently finding the original brushed main motor was not giving me the power it used to (it was also using much more power from the battery than when new and the flight times were getting shorter and shorter) I decided to take the plunge and upgrade to brushless.