Spindle motor or controller?

Hello Mike,

Some pictures of the internals of that motor might help.
I know that the motor has an alloy outer case but a steel inner shell, a loose magnet might not be immediately obvious as it will stick firmly to the case until a rotating magnetic field causes it to move.
 
From the ohm readings you got back in post #3, it sure looks like one of the 3 windings is open. The three readings really should have been very similar. Most likely one of the lead-in wire connections inside has come loose or there's a cold solder joint- might be worth a bit of investigating, you might get lucky
mark
 
It's hard to see in the video but it looks like the motor is pulsing when it spins. Either the hall sensor has failed or there is a problem in the controller. I would check the voltage on each of the 3 phases at the controller if this is good then I would suspect the hall sensor may have failed.
 
I missed the readings in post 3. did you take these readings with the motor disconnected from the controller. If so re do the readings a reading of 1.8R is odd, but I do not think it would give you symptom you have.

From the video it seems to me that the controller is energising the wrong coils.
 
Knowing that there are three windings all connected in a triangle, seeing a 2 to 1 difference, postulating each winding must be about 0.9 ohm and the readings he should have got across any of the three would be 1.8 ohm in parallel with 0.9 or about 0.60- there has to be one open I figure
mark
 
warrjon said:
I missed the readings in post 3. did you take these readings with the motor disconnected from the controller. If so re do the readings a reading of 1.8R is odd, but I do not think it would give you symptom you have.

From the video it seems to me that the controller is energising the wrong coils.
Click to expand...
motor disconnected
 
When I said the 1.8R reading is odd I will explain a little more that I do not think it's a winding issue.

0.9R across 2 windings in series 0.45R per winding

Blu to Blk = 0.9R so Blk is 0.45 and Blu is 0.45 all good
Red to Blk = 0.9R so Blk is 0.45 and Red is 0.45 all good

This has tested ALL the motor windings and the connections coming out of the motor

It is possible the Y connection between Red and Blu is bad. I can not see anything else that would cause the high reading it is just odd the reading is exactly double.

Gh I would locate the Y connection and open it up to check. Looks like the hall sensor bracket is adjustable, mark where it is with a pin punch so you put it back in the same location.

My first guess at the issue would be a bad hall sensor, Marantz Cd players used to have hall sensors and they went bad on a regular basis, I replaced lots.
 
I was thinking delta, but even so, the readings should be closer I think
 
Warrjon,
I'm thinking it is the spindle control or the main board. We cannot get the new motor/drive to work either. We are still trying to find out what exactly the output of the boards should be, but it doesn't seem we are getting the voltages that DMM expected to see.

Jim Dawson is helping me right now (off forum). So rather than trying to do too many things at one time I will continue to work with him. I appreciate your help and may ask for your expertise again in the future.

I'll keep posting any progress here.
 
OK that's a good strategy. Quite often too many cooks spoil the broth............. I will keep posting if I have any input as it may prod you guys in the right direction. I have been repairing electronics for nearly 40 years.

I will say that trying to measure voltages in a timing circuit, even with the motor running slow the DMM will not tell you if the voltage is being turned on at the correct time. You need a scope, to see the difference between the 3 phases.

A large motor like this I would expect there to be driver transistors on a heat sink - Check each of the transistors and flyback diodes in the driver circuit with the DMM on diode test (YOU WILL TO ENSURE THE MOTOR IS DISCONNECTED FOR THIS TEST). If good check all the power supply voltages on the control board, This is easy to do with the DMM. There will be a precision 5.00 (or 3.3) volts there for the logic. The 5V needs to be ±0.1v.

If the power supply is switchmode check the high frequency ripple this could be 20 - 40 kHz. You can do this with the DMM on Hz and AC volts.
 
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