How to connect a brushless motor to a controller?

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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VRMinde   100 µW

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How to connect a brushless motor to a controller?

Post by VRMinde » Jan 13 2021 8:35am

I am installing the Kugoo Kirin S1 RWD wheel on my Xiaomi M365 scooter. I want the new wheel to run on a stock controller. Both wheels have the same amount of hall sensors - 3.
Image

How should I connect the wires correctly? My guess was that the hall sensor position is critical, therefore it should be like:
M365 - Kugoo
Yellow - Green (A)
B- - B- (-)
Blue - Yellow (B)
R+ - R+ (+)
Green - Blue (C)

But how do I know how to connect phase wires? Thank you for your help.
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Hall sensors.JPG
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amberwolf   100 GW

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Re: How to connect a brushless motor to a controller?

Post by amberwolf » Jan 13 2021 7:06pm

There is no way to know for sure which combination will work without testing them to find the lowest-no-load-current that spins it the right direction at the right speed.

You can *try* making sure the wire orders are the same, by matching the order of teh halls as tehy are on the boards you picture, *and* the phase wire orders as they are on the stator windings, but if the motors are wound in a different pattern from each other, that might not work.

If you do try it, then leave the motor wheel offground, and measure the battery current while slowly increasing throttle from zero to full. It should stay around 1A, maybe up to 2A, or less. If it is higher than that, especially significantly higher, or spins way faster than normal, then it's the wrong combo, and you'll need to explore other combinations of either hall or phase wires.

If it is in the wrong direction, then swap any two phase wires, and then experiment with hall wire combinations until you get the low current one that spins right.


Just curious--why change the motor? Did the original fail?

VRMinde   100 µW

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Re: How to connect a brushless motor to a controller?

Post by VRMinde » Jan 14 2021 2:55am

Thanks for the reply, I will be experimenting today and hope not to burn anything.

I am not exactly changing the motor - I am adding the second one :)

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amberwolf   100 GW

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Re: How to connect a brushless motor to a controller?

Post by amberwolf » Jan 14 2021 2:08pm

VRMinde wrote:
Jan 14 2021 2:55am
I am not exactly changing the motor - I am adding the second one :)
Well, if you don't already have one, you'll need a second controller to go with the second motor, so the easiest way to do that is to get a kit with both motor and controller in it that are matched for each other, so you can just plug in and go.

If you're already using a second controller identical to the original, then you should be set, once you determine the right wiring combination between it and the new motor. :)

As long as you use just a little bit of throttle, wheel off-ground, to do the testing, you shouldn't burn anything.

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TommyCat   1 kW

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Re: How to connect a brushless motor to a controller?

Post by TommyCat » Jan 14 2021 2:14pm

This may help...


Image
See my completed Magic Pie V5 rear hub E-Bike build Here!

VRMinde   100 µW

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Re: How to connect a brushless motor to a controller?

Post by VRMinde » Feb 03 2021 6:43am

Thanks a bunch mate, I was looking for this pic in readable size! :)

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speedmd   100 MW

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Re: How to connect a brushless motor to a controller?

Post by speedmd » Feb 03 2021 8:44am

I am somewhat horrified by this test to see approach. Having gone through it a few times just pisses me off to no end. Reminds me of a time I had a rigger move a old milling machine and before I could stop him, he disconnected the motor wires and pulled motor off so it would fit the box truck. 2 speed 3 phase motor with no wire markings.

All the top electricians and motor repair folks told me I had to rewind or go through this type of trial and error to find the correct wire orders.

Simple solution was to put a analog multi meter on the phase wires and slowly rotate the rotor to clearly identify the phase order. Worked perfect.

Halls order, in direction of rotation should be able to be done in somewhat similar fashion but easier due their on-off response. They will be A-B-C or C-B-A (1-2-3 or 3-2-1). Just marking - identifying the center leg on them would be a big help. Phase wires should clearly be induced with similar voltage spike as on the induction motor. Simply identifying phase and hall order on controller? Physical layout possibly?

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Re: How to connect a brushless motor to a controller?

Post by amberwolf » Feb 03 2021 1:26pm

speedmd wrote:
Feb 03 2021 8:44am

Simple solution was to put a analog multi meter on the phase wires and slowly rotate the rotor to clearly identify the phase order. Worked perfect.

Halls order, in direction of rotation should be able to be done in somewhat similar fashion but easier due their on-off response. They will be A-B-C or C-B-A (1-2-3 or 3-2-1). Just marking - identifying the center leg on them would be a big help. Phase wires should clearly be induced with similar voltage spike as on the induction motor.
This is what the "ebike testers" do, using LEDs laid out in a circle or in a grid. Using one of those makes it fairly easy.

But without one, while it seems simple to do this sort of test, instructing people on how to use a multimeter (itself a significant task sometimes, as they often don't follow steps *exactly*...and that's assuming they're willing to go buy even the cheapest one cuz they dont' usually have one), then how to setup a power supply with pullup resistor on each hall signal (since you don't get a valid signal without one, as the typical motor hall is open-collector), then how to look for the very small voltage pulse you get out of each pass of a magnet on a phase coil at slow speeds like just rocking a motor back and forth to get a single pulse while keeping track of a specific hall responding to the magnet at the same time, etc. (assuming that's the method used to match hall to phase).

Alternately, using six resistors and six LEDs and a 9v battery to build a simple version of the phase/hall part of an ebike tester....

If can come up with a good detailed step by step instruction set that someone with zero experience at anything electrical can follow, I can copy it to the Technical Reference area, and we can at least try to get people to try it.


Simply identifying phase and hall order on controller? Physical layout possibly?
Not usually possible because the winding pattern is not necessarily related to where the phase wires are tied into the coils, or the order they are done so in, vs where the halls are located and the order they are in. Similarly, the motor controller hall wire order on the board may not be anything to do with the phase wire order (though at least the phase wire connections to the fets are obvious), and the order the pads are on the board may also not be the order they go into the MCU input pins (though they probably are), and the order the MCU firmware *reads* the pins cannot be known even though it is likely they are read in the same sequence they are physically laid out in, one can't know if they started at the "top" or "bottom" or "left" or "right" of the pin order. :/

When I have tried it that way, I never found any consistency between motors or controllers with different designs or even very similar ones. :/ (even the order the colors are soldered onto the phases or pcbs in either motor or controller aren't always the same even within the same brand and model motor or controller).

But if you can find a way to do this consistently between different setups, it'd be a great help to those willing to open up their stuff to find out the order rather than an electrical test, and it can be copied over to the Technical Reference area.

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speedmd   100 MW

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Re: How to connect a brushless motor to a controller?

Post by speedmd » Feb 03 2021 5:37pm

I never found any consistency between motors or controllers with different designs or even very similar ones.
Thanks for filling in the details. Reminds me why it's frustrated me away from digging further into this rats nest. It's no wonder why many now come with self learn functions.

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