KL-6050 Stepper Driver Frustration

[tjp912]

Yes. The noise is present on the input to the drivers without the C10 connected.

[tjp912]

The problem originally started on the Z axis and is now happening on the X axis after I switched the driver around.

I've swapped the DIR and pulse signals around and the problem stays with the driver regardless of which control pins from the C10 that are used. This includes moving them to pins 8 and 9 which were otherwise unused. The problem followed the driver.

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This was a previously working setup that I purchased...when I got it home, the Z axis was acting like this.

[109jb]

Since the problem follows the driver, I would suggest that the driver is bad.

[tjp912]

I thought so too...so I bought a new driver. Same problem. Both drivers have the same problem, same performance, same crappy EMI. Quite frankly, given what I see on the scope, I'm impressed that anyone gets these to work. The thing is supposed to have an opto-isolated input, yet it's conducting all sorts of noise onto the 'opto-isolated inputs'. Something is wrong with the design regardless of the specific issue I'm having.

[tjp912]

The only common theme is that the problem is with the driver that's physically closest to the C10. Other than that, there's no apparent pattern that I can discern.

[jalessi]

Tom,

Is the noise present if the motor is completely disconnected from the drive?

Jeff...

[tjp912]

With only power connected to the driver and a scope connected to the input pins, the noise is present.

[tjp912]

Stop the presses!! I found the problem. The guy I bought this from apparently has terrible soldering skills and just happened to be lucky while he was using it. One of the motor phase wires has a cold solder joint making an intermittent connection. It was hidden by shink sleeving which is why I didn't see it before.

Thanks for all the troubleshooting ideas guys! But I'm off to fix a cable and start some milling.

[jalessi]

Tom,

One of my questions was "Is it possible you may have a loose coil wire on the offending stepper motor?"

Stop the presses!! I found the problem. The guy I bought this from apparently has terrible soldering skills and just happened to be lucky while he was using it. One of the motor phase wires has a cold solder joint making an intermittent connection. It was hidden by shink sleeving which is why I didn't see it before.

Thanks for all the troubleshooting ideas guys! But I'm off to fix a cable and start some milling.

Happy you finally found the problem!

Jeff...

[tjp912]

I know...you did ask that. I guess I just hadn't pulled on this wire hard enough until I started stripping off all the heat shrink and it came free.

All this being said, coupling noise onto an opto-isolated input is still poor noise performance and tempts me to design a driver...different topic.

[109jb]

Something doesn't make sense. You said it started on the Z axis and then moved to the X axis when you swapped drivers around. If this is the case then how could it be a cold solder joint on the motor wire?