sintered what?

[padailey]

I think it depends on when you got your HV 6.5 whether or not it has a sintered rotor. All Novak brushless motors now (since Jan I believe) come with a sintered rotor except the EX series (I think the crawler motor still uses a bonded rotor also). My experience with the sintered vs bonded in the 540 motors is that the sintered gives the following advantages.

1. Runs 15-20 degrees cooler
2. Magnet is much stronger (more torque better braking)
3. Since it runs cooler you can gear it much higher.... I went up 8 teeth on the pinion in my TC and motor barely gets to 130 degrees.
4. Novak's site shows the KV rating did not change but the power output did increase (Watts)
5. The rotor is supposed to handle up to 250 degrees before the magnet will fade... so it should shut down thermally way before any damage is done.

I would imagine what you would see in the 550 cans would be similar.