Motor winding help needed bldc

I'm just wondering if some one here can help! Iv been working on small hub motors for a skate board, I dont want to just go an offe the shelf convention, I have recently changed for 14pole to 24n28pole but my winding seems to be off.

I have wound it in a Wye configuration it seems to not be 120deg

These are my test results.

Ps. I can add square wave if it's needed.

jacobbloy said:

I'm just wondering if some one here can help! Iv been working on small hub motors for a skate board, I dont want to just go an offe the shelf convention, I have recently changed for 14pole to 24n28pole but my winding seems to be off.

I have wound it in a Wye configuration it seems to not be 120deg

These are my test results.

Click to expand...

After the last winding question thread, I'm almost afraid to rely :wink:

Did you change the magnets to go from 14 to 28 poles?

Yes I did

Did you wind it like this?

https://endless-sphere.com/forums/viewtopic.php?f=28&t=58014&p=865555&hilit=winding+wye#p865555

I just ran the motor in a jig at about 714rpm

I tested the voltage on each phase wire, the yellow phase group is 4v below the other 2
Phase A 8.14v, phase B 4.7v, phase C 8.14v.

A short via the stator iron ?

Lebowski said:

A short via the stator iron ?

Click to expand...

Mmm that is an idea but it could course more then just voltage drop.

I was suggested that one phase is terminated backwards. This will cause it to 'fight' the other two when you spin the motor.

One way to find out - sequentially give each pair of wires some amps (a power supply or a few D cells in series is good) and mark, relative to a stationary thing, where the motor moves to. For example, power A-B, then A-C, then B-C, then B-A, etc... for the full six states.

If your marks are evenly spaced, then there problem is somewhere else, but if they are grouped in two areas, a phase is terminated wrong. And it's 99% the B phase since it's non intuitive when you finish winding the A-phase that you need to move 120 degrees over to "start" it.

But I still need to test this.

I'd remove the rotor and energize each phase seperately with DC. Then check polarity of each energized coil. Kinda sounds like you have one coil backwards.

I did a jumper to swap the small and long B phase wires, then I did the test on the jig and tested the voltage and they where all the same so I bit the bullet and tested the motor hoping my soldering was good enough and I didn't short any thing. (I hate soldering enamel wire)

I spun up the motors and the high current draw is gone and it's seems like the timing is know correct!

Thanks every one so much for your help! And I hope this finds some one els who has this problem.