Most Unuseful Question Of Ever About Brushed Motors

[jeekelemental]

Happy new year to you all!

I've noticed that some of my brushed motors (mostly used, some refurbished) are easy to spin by hand than others. I'm deeply ingnorant about electrics and I'm prone to think that it's something about magnets. Am I right or not?

[jwscab]

Yes, some magnets are stronger than others. There are dry formed magnets and wet formed magnets (the way they are molded) and the recipes used to make them. The wet magnets are generally stronger and keep their magnetism better.

[GoMachV]

Springs will also play a small part in that. There were some pretty heavy springs out there.

[V12]

Beside magnets it´s also the airgap between the armature and the magnets what affects how easy you can spin by hand.
And there are big differences for the airgap.

Talking about differences of airgap at motors from the same company at similar time frame. I found at Losi Revolution motors.
Jack Johnson 1x12. Lots of airgap, makes the motor scream even more at full throttle.
Big Ed 4x15T. Very small airgap, one of the narrowest I have seen for a car motor. Less RPM and harder to spin by hand.