Stepper on the Fritz

Today I had a large project and I wanted to move my gantry to zero so I disabled stepper motors and pulled it about 20" towards the origin. I did this pretty quickly and the controller screen whited out and the controller restarted when I did. Since then one of the stepper motors has been acting odd. It produces a ton of vibration and noise and does not seamlessly move in tandem with the other motor. Here is a link to a video of it in operation: You’ll notice the conduit moves askew when I change directions. Anyone encountered something like this before and have any solutions?

What controller do you have and are you running dual endstops?

Check that your pulleys are tight. Then check the wiring. If one wire was loose, it can act this way.

You can also swap x and y (while off) to check the drivers.

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If you’re blue
And you don’t know
Why it won’t go
Or why it sparks and spits
Stepper on the Fritz

Thank you, I’ll be here all week. Don’t forget to tip your waitress…


Could have cooked a driver if it backfed too much voltage from moving it like that. Which controller board?

I’ve got the Rambo 1.4. running dual endstops. Good idea to switch the wires. When I do that the opposite stepper takes on the unusual behavior. It’s the one plugged in to E1. Do you think this could possibly be a firmware issue somehow? The onset would make me think no but I wonder…

You could try reflashing it, but I doubt that’s the problem. If it’s changed, it’s probably going to go completely bonkers.

So it sounds like it’s the E1 driver on the Rambo then? Is there a fix other than replacing the board?

You can wire the X motors in series. You will lose the ability to auto square while homing, but otherwise, it will work the same.

Yeah, unfortunately my workmanship is not solid enough to do without auto-squaring. It’s pretty essential in my setup otherwise everything is askew. So it sounds like a new board is in my future then?

What we did before auto squaring (and I still do this) was, install some hard stops. Pull the gantry (slowly :slight_smile:) to the hard stops, enable the steppers with a movement. Then they will move in lock step. You just have to get some hard stops that are placed so it starts square.

But IMO, yes, this driver is busted.

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If you have to backdrive a motor, do it SLOWLY since output voltage is proportional to shaft speed. Keep it under the speed where the controller LCD lights up and you’re golden.

You should not be able to kill a driver that way on these boards.

I suggest trying again, for a test swap the x and y axis plugs, make sure it really follows.