How does a DC motor work without a commutator?

[Oti]

How can this DC motor work without a commutator. Should it not turn no more than once and then stop because on one side the rotor is attracted to the magnet?

An answer I can think of is that the rotor is repelled on one side and attracted on the other by the same force which neutralize each other so what counts is the force you give it in the beginning when you spin it with your hand. Or is it the momentum that gets it over the being attracted part of the circle? What do you think?

It works very well. There are many videos and I tried it myself.

 

[mrspeedybob]

That motor does have a commutator of sorts. I'm guessing when you tried it, it didn't work.

If you had actually built this, and it worked, you'd know how the commutators function is accomplished.