I want make outrunner BLDC motor by myself. I am looking for an easy and cheap way to get the inner stator part of it if available.

I see this AC motor armature and it uses almost same shape and materials. What I found different is that in the AC motor, the thickness of the stacked plates that make core is around 0.5 mm and on the other hand generally BLDC has around 0.2 mm.

How does it affect motor performance? Is there any other consideration I have to keep in mind?

  • \$\begingroup\$ AFAIK there are no out runner AC motors, so it's very unlikely that stators exist, but you can prove otherwise. \$\endgroup\$ Oct 22, 2021 at 7:37
  • \$\begingroup\$ I am talking about out runner BLDC motor's stator. and inner rotor of AC motor. \$\endgroup\$
    – dharmikP
    Oct 22, 2021 at 7:59
  • 1
    \$\begingroup\$ @MarkoBuršič AC outrunner here... you couldn't use this rotor as a BLDC stator, but the stator might be usable as a BLDC stator. electronics.stackexchange.com/questions/486506/… \$\endgroup\$
    – user16324
    Oct 22, 2021 at 12:41
  • \$\begingroup\$ Can you post a picture of what you have? Most induction motor rotors that I have seen are not like outrunner stators at all. So I just want to see what you have because my mental picture is failing me. \$\endgroup\$
    – user57037
    Oct 22, 2021 at 14:35

1 Answer 1


Reducing the lamination thickness reduces the eddy-current losses in the iron. The eddy-current losses are proportional to the squares of the flux density, the frequency and the thickness of the iron.

Other considerations to keep in mind are the number of phases in the stator winding and the number of poles. A single-phase stator will often have a main winding and an auxiliary winding. Those windings might be considered to be two phase windings, but they are often wound with different numbers of turns and different wire gauges. That would not serve well for a permanent-magnet motor. Many single-phase motors have only one powered stator winding. The second winding would be a single turn or a few turns of a shorted, shaded pole winding.

Ceiling-fan motors often have have three speeds that are achieved by winding the stator with a selectable number of poles. That would also be problematic for conversion to a permanent-magnet motor.

I am talking about out runner BLDC motor's stator. and inner rotor of AC motor.

This comment should be a revision to the question. If you are talking about an AC motor with a wound rotor rather than a squirrel-cage rotor -- a rotor with slip-rings. That could probably be used as an out-runner stator. It would have a three-phase winding, but you would need to determine the number of poles. Such motors are uncommon compared to squirrel-cage motors.

If you are talking about an AC motor with a commutator, that is commonly known as a universal motor and rarely called an AC motor since it is really a DC motor adapted for AC use. The rotor is totally unsuitable for use as a stator for a permanent magnet out-runner.


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