4 pole conversion?

[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.

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...

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:


4 pole rotor & slotted stator


2 pole slotless stator

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.


2 pole


4 pole

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

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:

.
.
.

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.
.
.
.

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.

Avner.

[Pdelcast]

Don't do it, it won't work.

You'll just end up smoking the ESC.

Wrong winding type for a 4-pole...