[lutach]

I have the same type of rotor, but it came with 1/8" shaft. Here is the deal, the magnet is too strong and it causes a higher Io current which have shown it will cause motors to over heat. With that in mind, that rotor assembly will work best with a lower Kv motor of around 1000-1300 to keep the Io low. Hacker and Lehner uses a lower strength magnet (Different material as well), but it works out great. Not always using a stronger mgnet will make it better.