Today I noticed that, despite being energized and responding to movement commands, my Y1 motor has no stiffness at all under power. I can push it around very easily while its under power. I double checked my wiring and danced my Y0/Y1 and the issue did follow the cable, which tells me the board/provided voltage is as expected.
Is this a typical symptom of a stepper motor failure? I am fairly certain it is, but I have not once seen a stepper motor fail in 7 years, which is the only reason I am asking. Going to order a replacement regardless, but I was curious if anyone else has run into this issue. The only thing that has changed recently was that I swapped out my board for a Jackpot2. Are there config settings I should validate before ordering a replacement stepper? I would think if it was a config issue the issue would be isolated to the port on the board, but I am no expert in this.
Stepper motors seldom fail. I have steppers from old lulzbot printers that accumulated tens of thousands of hours of runtime and were still running fine.
You just swapped to a jackpot. What are your run and hold current set to in your config.yaml?
Are these motors from Ryan or sourced elsewhere?
If not from Ryan, what are the specs, most importantly the coil resistance and rated current?
Hey Jim! That was my instinct too. All motors and parts are from Ryan. Sitting in a ground blind right now waiting for some deer to come by. I’ll check my config as soon as I get back to my shop and update this!
I got it checked! It looks like everything across the y motors are running at .7 and .8 and the values between the 2 y motors match.
As an additional test, I went ahead and jogged the gantry back 500 m and the entire time that the gantry was moving, I was able to move the Y one motor by hand while it was also moving. Pretty odd behavior.
This, or something very similar, happens to my X axis sometimes. Rebooting the machine usually fixes it. I’ve not pinned down the cause yet. Thinking maybe intermittent fault in the wiring loom?
I’ve rebooted multiple times, reseated cabling, and even tested the different ports on the control board the symptom always stays with the motor. I ordered a new one, and will swap it in tomorrow to see if the issue persists! Maybe one of my extenders got nipped at some point?
Ah your motors are the wires attached style, so less potentially dodgy soldering joints than mine. But yes, maybe try swapping the extenders over and see if the problem swaps?
Turn off the jackpot. Using a DMM and a probe pin, measure the coil resistances as seen at the connector where it plugs into the jackpot (de-mate the cable to make this measurement looking into the cable). How does that compare for the two Y motors versus the X or Z motors?
What temp do the Y steppers run at? How about X? This acts like you’re not getting full current to the motor. VERY strange.
Ill whip the multimeter out assuming my grub is fine. I also have an extra motor that came in I am going to try and see if the problem is persistent. By tonight, at the least, we will know for certain where the issue is.
Remember to set one of the grub screws on the flat part of the shaft. If you didn’t do this on your original build, now might be a good time to do it for all of the motors.
. And while you are at it, put some loctite on the screws.