Mamba Monster Motor Malfunction?

[brijar]

I've been at college for a couple months now and have met a fellow with a nice truck. It's the newer E-Maxx, but he put a Savage transmission (XL I think. 3 speeds with no reverse) and a Mamba Monster (he says the 2200KV one) system in it and runs it on 6s (Thunderpower, I think) lipo. It's a very nice truck, esp with the General Lee body.

I've never seen a Mamba Monster in person before (I have a Mamba Max in my Rustler), so I was quite surprised to turn the spur gear on his truck and find that it turned like there was a rock in every tooth of the gear. I noticed he had his gear mesh set very tight and I thought the jerky turning was due to that. Today I got to turn it with the pinion loose on the shaft and it's as smooth as butter. The motor shaft, however, seems to have a heavy magnetic resistance, unlike my Mamba Max 5700 and my Feigao 9L. Is it just because it's such a higher quality of motor? Or is there something wrong/different about it? And how many poles does it have? I'm not really sure what the poles of a motor means (I think my Mamba is a 3 pole?).

Thanks,
Brijar!!!

[What's_nitro?]

It's magnetic drag caused by the strong rotor magnets passing by the steel laminations in the stator windings. It isn't necessarily because they are higher quality than other motors, just a different design. Lehner, for example, does not use steel laminations in the stator, and so their motors all spin freely. All Neu motors (Castle motors are based on them) will have that "notchy" feeling. The smaller Castle motors also do not have steel in the stator, so they are smooth.

The Neu-based Castle motors have 12 slots in the steel stator and 4 poles on the magnetic rotor.

[sikeston34m]

Your mamba max 5700 motor is a 2 pole motor. It's field winding is completely built from compressed copper windings. In this type of field, there is nothing for the magnets to be attracted to, unless of course, the windings are energized.

The CC 2200kv is a 4 pole and has iron cores in it's field windings.

The magnets of it's rotor are attracted to these iron cores. That's what your feeling when you turn the motor.

[brijar]

Ok great! Thanks for clearing that up. Is either of these designs better than the other? I would think the freely rotating shaft would be more efficient as far as coasting goes.

[suicideneil]

2 pole motors spool up faster but prefer lighter gearing, 4 pole motors generate more torque and thrive on taller gearing, in general terms. I think I've seen it said that 4 poles have a higher natural dragbrake, so coasting would probably be smoother with a 2 pole motor- horses for courses really....