Dual brushless motors 1 controller ?

jk1

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Feb 27, 2009
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Is it possible to just parallel 2 identical brushless motors to one controller ? Assuming the controller is able to handle the current of both motors.


The motors will be linked by a chain , and only one motor would have hall sensors , would this work or would one motor go out of sync slightly ? Hence would this only work if both motor shaft were mechanically connected ?

Also is it possible to change the hall wire phaseing so one motor is going forwards and one backwards with only one controller?
 
I do not know of an ebike controller that is 2-channel. Having one wheel move in one direction and the second in the opposite can be accomplished by swapping the phase & signal wires.

What is the intended use?

Good hunting, KF :)
 
jk1 said:
Is it possible to just parallel 2 identical brushless motors to one controller ? Assuming the controller is able to handle the current of both motors.


The motors will be linked by a chain , and only one motor would have hall sensors , would this work or would one motor go out of sync slightly ? Hence would this only work if both motor shaft were mechanically connected ?

Also is it possible to change the hall wire phaseing so one motor is going forwards and one backwards with only one controller?

Provided that both motors are mechanically kept in sync, with the rotors in identical positions relative to their stators, then yes, it will work. The problems are:

1. Getting the rotors aligned. This needs to be better than just doing it mechanically, as there's no assurance with a lot of motors that the stators are at the same angle relative to the mounting plate. One way to do it is to put DC at a limited current (may be a few amps) through the same winding on each stator, with the motors not mechanically connected. The rotors will lock at an angular position that is where you want to connect them together.

2. The other problem is that the motor apparent winding resistance will be halved, as far as the controller is concerned, so the controller will need to be able to deliver enough current. The good news is that the motor apparent inductance will double, giving the controller an easier time.

You only need Halls on one motor, as you've already worked out. I'm not sure whether a chain will be accurate enough to make the two motors run smoothly, unless it's pretty tight, when it might well have a high wear rate and be noisy. A toothed belt might be better, or better still try and mechanically lock the shafts together as one.
 
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