Hi, I’m new to the forum. I’ve had my Altmill for over a year. I noticed a buzzing noise from the Y2 stepper motor when it’s stopped. When I first noticed it, both Y motors were very hot.
If I turn off the power, the noise stops and it seems to release tension on the gantry. Leadscrews turn freely and no alarms. Where do I go from here?
I also get a buzzing noise on occasion. Sometime it sits and buzzes a bit, sometimes it sits quiet, then buzzes for a bit and then goes quiet again. Have you tried twisting the leadscrew a tiny amount and if you did that, did the buzzing stop?
What I believe is happening is that the closed loop control system sees a slight (as in a tiny tiny fraction of a mm) discrepancy between the commanded position and the actual position. It attempts to correct the position but the discrepancy is so small that the correction does not ‘stick’. The position reverts back to the old position and the control system attempts to adjust the position again. This happens rapidly over and over and is audible as the buzzing noise.
Next time the buzzing occurs, try to twist the leadscrew ever so slightly (so slightly that you feel that looking at it hard enough will cause the buzzing to stop) and if the buzzing stops you have discovered what the issue is. I do not believe this to be a problem but rather a normal reaction of the control system. It might possibly be something that could be corrected by tuning of the control system but this is not something an end user can do nor is it something that is an issue in actual operation.
In regard to the ‘very hot’ motors, stepper motors can run surprisingly hot. If you grip the motor with your hand, can you hold on to it for more than a few seconds without feeling that your hand is getting burned? If it is hot but you have no issue holding on to the motor then it is running within acceptable temperature limits. I do not know if there are any parameters for motor current and holding current that are configurable via your controller or not or if they were ever changed for some reason but this can affect motor temperature. You might also want to verify that the dip switches on the motors are set as per the setup instructions.
Failing all that, I would open a ticket with Sienci to see if they think that there might be an issue.
Thank you for the detailed response. I will check it out. I haven’t made any changes since the initial setup. Just maintenance, checking fasteners, cleaning, and lubricating.
@Briannackers Mine does it from time to time. If I’m bothered by it, I jog in the Y direction until it stops. Or I power off the SLB if I’m not going to use the machine for an extended period.
I did find that turning the ball screw slightly would stop the noise. Also jogging the Y axis a different direction also helped.
Thank you!
Not sure if this is related but with my original LongMill MK1 setup, open loop motors and no off switch for the controller except for the E-Stop, the motors would hum after awhile if I forgot to push the E-Stop before I left the mill for the day.
I’m not positive but I believe it was related to the PC going to sleep after awhile. I was running Windows on a laptop and it never when to sleep when running the mill but I would close the lid when not running the mill. The hum didn’t start right away it would be something I noticed walking by later.
I always shut my SLB and PC down now so I don’t have any recent experience to offer. I have liquid cooling I’d rather not keep running 24/7.