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Help! One pololu driver is getting hot + motor sound

Posted: Tue Jan 12, 2016 3:10 pm
by janapriya
I have a stepper shield from reactivesubstance.com (http://www.reactivesubstance.com/shop.html)

Y'day I've noticed one stepper motor is making a little sound (like shhhhhhhh :-) ). And I found corresponding driver is getting hot.
I did,
1. swap drivers - the new driver in the same socket getting hot. So it is not due to faulty driver.
2. swap motors - the new motor making the same sound. So it is not the motor or cable connecting the motor.
3. swap Arduino Uno - problem persists. (giving my luck, I just wanted to make sure something funny is not going on, hence tried that).

Any help highly appreciated!

Thank you

I noticed everything after making my new Electronic Enclosure.
- http://www.shapeoko.com/forum/viewtopic ... =20#p58558
OR
- https://plus.google.com/+rjanapriya/posts/UumxVQvTxjJ

Re: Help! One pololu driver is getting hot + motor sound

Posted: Tue Jan 12, 2016 4:30 pm
by janapriya
The driver at the top left socket is getting hot (as I mentioned above, if I plug a new driver at that socket, it gets hot as well). That socket corresponds to the left Y stepper motor. Other drivers are not hot.
IMG_9785.jpg
IMG_9785.jpg (412.96 KiB) Viewed 973 times

Re: Help! One pololu driver is getting hot + motor sound

Posted: Tue Jan 12, 2016 5:41 pm
by cvoinescu
The only possible explanation I venture to give is this. If I remember the layout of the buildlog.net shield correctly, the ground plane beneath that driver is connected to the rest of the board only in a few thin spots. You may be seeing some form of oscillation due to voltage drops on the ground connections. One way to try to fix this would be to take the shield off, remove the drivers, and, on the back, solder a wire connecting the ground pins of the problem driver together, and another wire connecting one of these to the ground of the motor supply. The ground pins are the ones with square pads on the Pololu modules (and labelled GND). On your top-left driver, as pictured, they're the top pin on the left, and the second one from the bottom, also on the left (right next to the top of the brown capacitor).

To test this theory without soldering, get a short piece of thick, solid (non-stranded) wire, and, very carefully, touch the top-left pin of the problem driver to the top-left pin of the driver below it, without touching anything else. Does the noise change, or stop? (Be very careful not to touch anything else with that wire. Do it without power first, as a dry run.)

Re: Help! One pololu driver is getting hot + motor sound

Posted: Tue Jan 12, 2016 7:14 pm
by janapriya
Thanks a lot for the reply. Let me give it a try and get back to you.

Re: Help! One pololu driver is getting hot + motor sound

Posted: Wed Jan 13, 2016 5:49 am
by janapriya
Unfortunately it seems not the issue. But, thanks a lot for the input.

Re: Help! One pololu driver is getting hot + motor sound

Posted: Wed Jan 13, 2016 2:02 pm
by cvoinescu
Sorry -- it was a bit of a long shot. I don't know what else would cause a particular position on the shield to act up. Have you tried swapping the two Y cables, to see whether the problem might be caused by a cable or the motor?

Re: Help! One pololu driver is getting hot + motor sound

Posted: Thu Jan 14, 2016 11:54 am
by janapriya
Yes, I've tried that. When I did that, the new motor started to make the sound and the driver heated up (in the same socket).

Re: Help! One pololu driver is getting hot + motor sound

Posted: Thu Jan 14, 2016 2:44 pm
by cvoinescu
So there's something about that socket, but what? I'm baffled. I'm baffled and curious enough that I'd like to send you a GAUPS to try, if you PM me your address.

Re: Help! One pololu driver is getting hot + motor sound

Posted: Fri Jan 15, 2016 4:55 pm
by janapriya
Thank you, I've sent a PM