Originally Posted by suicideneil

Why would you need to change any settings?

The only difference so far as the esc is concerned is that it 'sees' the 4 pole motor as spinning twice as fast due to the extra 2 poles on the rotor, so the total rpm limit you can achieve with 4 pole motors is half that which you can achieve with a 2 pole motor.


That is exactly why I think that it is possible that if a 4 pole rotor is placed in a 2 pole can it will run (with the ESC switching twice as fast).


Same as a 2 stroke engine vs 4 stroke again; both engines of a similar size will move your motorbike just as well, but the 4 stroke will produce more torque and make a nicer rumble when you open it up, vs the 2 stroke which sounds like a bee in a tin...

I think the analogy is right from the performance point of view but wrong from the design point of view. 2 strokes use ports and 4 strokes use valves and camshafts while 2 and 4 pole motors both use rotors and stators.


You need to look at some pictures of the insides of a 2 pole & 4 pole motor of the same size to appreciate the physical differences ( and understand why you cant swap rotors ), but they still work in the same way when powered by a suitable esc.

Have a gander at this:

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The rotor on a 2 pole motor is usually a solid long, round magnet with the shaft running through it. The rotor on a 4 pole is made of 4 separate magnets fixed around the shaft & wrapped in kevlar or carbonfibre usually- the stator is designed to work with a certain type of rotor so changing it could cause it to not work properly, or not work at all.
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I have opened many brushless motors including the Castle 1/10 2 and 4 pole motors and even though I haven't made any measurements at the time, the rotor shape and dimensions look very similar if not identical.

By all means try it though, just make a video so we can all watch what happens....

I have 2 CM36 4600KV that are candidates for this conversion. They are the older design with the end-bell glued on and I really don't like opening them.
I don't even think that 4 pole rotors are available to buy as a rebuild kit right now, so even if it works I won't be able to run the converted motor without sidelining one of my 4 poles.

These are the reasons I was hoping to get some input from Patrick and instead of going ahead and trying it.