Everything was running smooth as could be when I noticed an odd noise after a cut job finished. It sounded like a full hard drive searching for files. I don't have a hard drive in my shop. The noise was coming from my steppers! I don't have anything electrical running, or anything new plugged in that I didn't already have there. I turned off the power supply for a while and switched it back on and it was fine for a minute and it went back to making the noise. I jogged the machine around, and it sounds like it's going to fall apart. It smooths out on occasion, but seems to be getting worse with time. I checked my wiring connections (all seems ok). Checked the voltage from the power supply (24v steady) Turned the voltage down and up, and it just made the noise decrease or increase. I tried adjusting the amperage (no change). Not sure whether the control board is screwed or what is going on. I also disconnected the usb cable with no difference. Z axis doesn't seem to be as bad in the video, but it is affected the same way when jogging it. The steppernoise file is the noise it is making while just sitting there powered on.
Wow, that doesn't sound good. It really sounds more mechanical in places than stepper noise. You've done lots of sensible and logical checks. My next action would be to disconnect the couplings between the steppers and screw,s then run a little program to see how the steppers sound on their own. How hot are the steppers getting? That carving you show in the video, is that what you have just finished? That was a big job, I wonder if it over-stressed something?
Yes, it really does sound mechanical, but I am 99% certain it is not. I believe it is the pulsing of the steppers coming through the machine, making it sound like a mechanical issue. The file I attached with Last Supper photo, was the machine just sitting there, idle. I did do a 4+ hour job just before the problem occurred, not the one in the picture though. Those motors shouldn't make noise like that sitting idle. No way all 4 axis couplings are going to come loose simultaneously. Besides, I checked them as well. Everything is tight. Steppers get warm to the touch, which seems pretty normal. I guess I will try your suggestion and disconnect the lead screws just to rule that out for certain. First, I am going to try running the same cut file I ran while taking the video now that the machine has sat powered down over night. Could be the motors I guess?? I'll update my findings shortly.
Okay, so before ripping anything apart and after 15 hours of sitting powered down, I ran some gcode. https://photos.app.goo.gl/jeWJL7iXTiMbeQKC6 It is running normal once again. Either I have the voltage set too high (24v), or too much current for the motors to handle under long duration. I am only guessing here, but it can only be one of 3 things. The steppers, the control board or the power supply. I am going to say the steppers just because the Z axis was running pretty smooth compared to the other axis, less load/ stress, on that motor? IDK for sure, but if it was a mechanical issue, I don't think it would have gone away by sitting.
Both versions of the Openbuilds NEMA 23 steppers should not have an issue with 24V nor should the xPro V4 be able to provide too much current. The 8825 drivers the xPro uses can be noisy but I'm not sure if heat build up would make a difference. Do you have a fan on the drivers? What do you have the stepping set at? Also did your steppers come from Openbuilds and which model are they?
They are the steppers that came supplied with the Lead 1010 machine. The control board is running 1/16 micro stepping, and is mounted in the open case mounting kit /w fan blowing directly on the drivers.
Hi Jack can you please try switching decay modes to see if this has any effect on the system. BTW were you cutting metal at the time it bagan to flake out?
Yeah I can try that. I haven't ran any long jobs since this happened. And nope, no metal cutting has ever been done on it, so no chance of a short from shavings
Okay... Slow decay recreated the problem instantly. Fast decay runs normal, as does mixed. Mixed (default) is where it has been, and where is was acting up on extended run. I'll try leaving it on fast decay on my next long cut, unless you think it might indicate something else?
Jack I've had similar sounds before and they were caused by a loose screw somewhere. Actuating the steppers causes you to hear it. Adjusting the steppers can also change it since you're changing the energy source. Fast decay for me results in smoother operation so this might be consistent with what you are experiencing. Can't say for sure it's a loose screw somewhere but I have had similar noise from that. It can be difficult to track down by ear because the metal makes the sound appear everywhere.
I think Jack may be on to it. That familiar sound does seem like it could be a loose connection somewhere along the line. I would suggest a power down and (another) once over on all the connections, tugging on each wire just to make sure before moving forward. May not be the cause but best to rule it out.
So what electrical connection would cause interference on all axis besides a bad ground coming in? I will go back over all connections AGAIN. I suppose any shorted wire pair running through beam channel would cause it as well. I'll post back later.
Absolutely it can go away mysteriously by simply sitting there. I don't want to doubt your troubleshooting but Gray made an excellent suggestion. Disconnect the coupling on one of the steppers. In fact fully dismount the stepper so there's no mechanical connection to the machine. Either hold the stepper in the air, or lay it on a towel so its vibrations while stepping can't conduct to your machine. This is a fast test to isolate if it's mechanical or electrical. If the noise goes away, do it again while holding it against where it mounts. If there's no abnormal noise while floating, but it comes back when it touches the machine then you probably have a loose fastener somewhere. If it's an electrical problem then noise may change/reduce when removing the stepper temporarily but it still won't sound right. Also beware problems like this can be intermittent, especially when your fiddling with it. So you may think for a moment you found it, only to have it come back.
Well I took the steppers off the machine, and switched into slow decay mode. They feel rough running in my hands. They sound rough while holding them. Checked all the wire connections by pulling on each wire, then took the wires out of the connectors to make sure they were making contact on the wires and not just the insulation. Re tightened the connections. Pulled on each wire again. Ran the motors again. Still run rough. Switched back to mixed decay mode. Motors run and sound smooth in my hands. Fast decay mode, I hear a slight hissing sound, or something like that, coming from the motors, but they run and sound smooth. Mount the motors back on the machine, and it is as it was before. Rough sounding in slow decay mode, smooth and normal sounding in mixed and fast decay mode. I will need to run a long cutting job to see if it acts back up, but I suspect that it will.
The hissing sound in fast decay mode is normal. I leave mine in fast mode. I'm an electrical design engineer. I've looked at the spec sheet for the driver chips on that board. The smoothest and most linear operation will be in fast mode. Slow mode is an attempt to conserve power. Mixed mode tries to automatically switch between the two based on current conditions. However changing dynamically between slow and fast can cause nonlinear microstepping. Fast mode avoids this, but you have to tolerate the electrical noise you hear. Smooth operation is more important to me. Also the supply voltage can have an effect on this too. Everyone likes using 24 volts for faster current ramp up but it comes with a cost. The driver chip tends to overshoot the waveform a bit the higher the supply voltage and this too can result in nonlinear operation. If there's an adjustment on your supply consider reducing it some.
Just posting to let you guys know that since switching the controller to fast mode, I have not experienced the issue again. That seems to have solved the problem as far as I can tell. I have ran a couple 10 hour jobs, and a handful of 2+ hour jobs, and it remains running smooth. Thank you all for your input, and help.
