Stepper motor extremey hot - update: blew a tb6560 chip

[_AR_]

Hi. I am configuring 3 nema 23 vexta 2A motors driven by the chinese TB6560 3 axis driver board and a 27V 13A power supply and controlled with EMC2. Everything seems to work well, despite the motor noise which seems to be caused by the cheap driver. One of my motors, however, is a bit more problematic. Sometimes, when powered but not jogging, it is jumpy and more noisy than the others. It also gets extremely hot, too hot to hold, while the others seem to remain cool. Is the motor just bad?

[kineticstep]

Switch the motor with one of the others and see if it acts the same. If it does, then yes something is wrong with it.

[_AR_]

Wow, can't believe I didn't think of trying that. haha thanks. I switched the problematic motor's connection with another one, and it still acts the same, so it must be the motor. Is there anything one can do about a bad motor short of completely recoiling the coils? The thing works and does what I tell it to do, it just gets way to hot and is quite noisy. I do have extra motors I can use, I just originally planned on using these 3 since they are the same and had nice lead wires on them and good documentation to make hooking them up easier. I guess I'll see if these other ones I have work. They are 8 wire though and only have a pin connector without wire leads... I guess I'll heat up the soldering iron.

[_AR_]

Well I went to wire up a different motor and now my 3 axis board is a 2 axis board. haha. The motor says it is only 1.75 amp! my other motors are 2 amp and work fine! Why did this one fry the chip!?

[osphoto]

I've had my motor wiring connectors over heat, found I was pushing to many amps to it.

Either way, the cabling became lose and caused various issues.

[_AR_]

I took the bad stepper motor apart (why not), and don't see anything obviously wrong (no odd looking coils, loose wires, etc). Anyone have experience looking at a bad stepper?

[doorknob]

I took the bad stepper motor apart (why not), and don't see anything obviously wrong (no odd looking coils, loose wires, etc). Anyone have experience looking at a bad stepper?

I certainly don't, but I'd be curious about the winding resistance measurements (is the DC resistance of one of the windings - or half windings - very different from the others?)...

[gamron]

Hi AR,

First check all connections, DB25 cable and your cnc software setup, if problem still exist then change connection of your problematic motor in electronic driver card with one of other good axis, if problem shift to good axis, driver card is partly damage and if not your problem is motor damage or mechanical problems of axis, replace motor with a good proper one, if problem still exist, you must check load momentum, lubricating, coupling alignment, deformation and other important mechanical parameters in your bad axis.

Stepper motors are very sensitive to bearing ware, air gap clearance between rotor and stator, absorbing small iron particles to permanent magnet rotor and hard to repair.

Best Regards,

Gamron

[Dorsal]

And polarity!

[_AR_]

Hi AR,

First check all connections, DB25 cable and your cnc software setup, if problem still exist then change connection of your problematic motor in electronic driver card with one of other good axis, if problem shift to good axis, driver card is partly damage and if not your problem is motor damage or mechanical problems of axis, replace motor with a good proper one, if problem still exist, you must check load momentum, lubricating, coupling alignment, deformation and other important mechanical parameters in your bad axis.

Stepper motors are very sensitive to bearing ware, air gap clearance between rotor and stator, absorbing iron fine particles to permanent magnet rotor and hard to repair.

Best Regards,

Gamron

Hi, thanks for your reply. As I stated in my other replies, I have tried swapping the connection with another motor, and the problem is with the motor itself, not the driver. I figured there was pretty much nothing I could do, so I decided to take the motor apart. Nothing LOOKED wrong to me, but I didn't test anything more than just simply looking at it. Took the rotor out, so the motor is shot anyway because I demagnetized it.

[gamron]

Hi,

I think nothing is wrong in your stepper motor and problem is simply current setting (with potentiometer or DIP switch) on your driver card for this lower impedance motor.

You can clean and montage your motor and test with lower current setting on driver card.


Regards,

Gamron

[_AR_]

gamron,

Are you referring to the first motor that didn't work, or the motor that blew the tb6560 chip? I will admit, I wanted to set the amperage to the lowest setting on the DIP switch before trying the motor that blew the chip, but forgot. I ordered 2 replacement chips, so maybe I'll try that one again... haha.
The first motor I mentioned in the original post is a lost cause at this point, unless I can find a way to remagnetize it.

Thanks again,
AR