Roll Resistance

[obessedwithrc]

Does anyone know what type of resistance a motor should have when there is no power to the car? I know that the resistance can change when the motor has a "charge" since it's magnetic.

I have a few Castle 1520s and they seem to have such high resistance. It takes quite a bit of effort to move my MT410 forward. I can hear the pinion and spur clicking loudly. If I disengage the pinion, the truck rolls super smooth and has no resistance. It could be that my mesh is too tight, but I don't think it's that, either.

I'm wondering if maybe I have a seized bearing, or the 1520 is such a powerful motor, that it's going to have some natural resistance when it has a charge left over.

Thoughts?

 

[Sandracer_NL]

IFAIK it depends on motor brands and or types. Some big high power (high Watss) motors can manually be turned easier than some smaller less powerfull motors.
A motor bearing gone bad can indeed cause more friction. Stock motor bearings are not the best bearings and need cleaning or a new one after some use. Especially if you run in sandy or dusty environments. Have a look at the motor bearings (front and rear one) and see if they are crunchy or have play in them. If so, replace them.
Hybrid ceramic bearings are a nice upgrade for your motor.

 

[Dan B.]

It also depends on the motor and what’s in there. I remember when I first got into TP motors I tried to turn a shaft by hand and was like, ”is this thing seized up?” Massive, powerful NEO magnets, how many poles the motor has, etc. can make a huge difference from brand to brand.

 

[Hector_Fisher]

+1 to both responses above. Motors come in all shapes, sizes, builds, and qualities. Hard to gauge just on spinning by hand alone without getting into the very specifics of your particular situation.

Best way IMO is to connect it to an ESC/battery and spin it up with no load. Shouldn't make any grinding/scraping noise and should take at least a few seconds to spin down from full RPM. Bonus points if you do it when you first get the motor so you can get a baseline and monitor bearing health.

 

[KnowAir]

I have noticed some turn much harder than others, even when new. For reference, I only buy lower end stuff so, no Castle or TP here. I always say to myself, "oh, this must be a good one, turns hard, nice!" I agree with what's been said, higher quality magnets is likely the culprit. It'll tell you once you run it I guess?

 

[gotnitro]

Stator slots and air gap is the reason for notchy motors. Not a bad thing but not necessarily a great thing either. There are plenty of BL motors that spin freely that make gobs of power too.

 

[obessedwithrc]

IFAIK it depends on motor brands and or types. Some big high power (high Watss) motors can manually be turned easier than some smaller less powerfull motors.
A motor bearing gone bad can indeed cause more friction. Stock motor bearings are not the best bearings and need cleaning or a new one after some use. Especially if you run in sandy or dusty environments. Have a look at the motor bearings (front and rear one) and see if they are crunchy or have play in them. If so, replace them.
Hybrid ceramic bearings are a nice upgrade for your motor.

Castle says they do not recommend ceramic motor bearings for bashing because they may crack. Have you had that experience?

+1 to both responses above. Motors come in all shapes, sizes, builds, and qualities. Hard to gauge just on spinning by hand alone without getting into the very specifics of your particular situation.

Best way IMO is to connect it to an ESC/battery and spin it up with no load. Shouldn't make any grinding/scraping noise and should take at least a few seconds to spin down from full RPM. Bonus points if you do it when you first get the motor so you can get a baseline and monitor bearing health.

Super helpful. Thanks, Hector!

 

[Sandracer_NL]

Castle says they do not recommend ceramic motor bearings for bashing because they may crack. Have you had that experience?

Super helpful. Thanks, Hector!

Nope. I run (hybrid) ceramics in all motors (Hobbywing and Leopard; I don’t have Castle). They are (way) better than stock. I never heard they crack. Maybe Castle means FULL ceramic bearings?
I had stock motor bearings completely disintegrate though.