So Idk if anyone else has had this problem but when ever my steppers move or start i get this high pitch noise not sure if you can hear it or not on the video but it doesnt sound good was just wondering if you can think of anything. I’m new to this and just got my printer wired. The end stops are not working which im looking into. This video shows right after it moving just a little then the sound continues tell i click stop motors
What you’re hearing is the stepper driver’s PWM frequency, which is a totally normal thing. It can be reduced by turning down the motor current (at the expense of torque output) or by using a slow decay mode, if your drivers allow you to select it.
Ok that makes since. You turn that down using software or the little screws on the motor drivers
Yeah but you want to be really careful doing so. Those little pots are pretty well kown for being a pain to tune especially on the little polou drivers. Apparently there is a resistor hack to make it easier to tune. Basically though for these (common) drivers you power only the ramps board by usb. No 12 v supply at all. Measure from ground to the pot body. A stock setting found on the web is .4 v. a bit of googling should get you enough info to know what to do.
I suggest reading before tuning those. I am not trying to give you answers or specs to tune to but to lead you to the answer. Potentially you can blow your motors or drivers doing a bad job at this. You definately dont want to go turning those blindly. Get a meter , do it right.
Motor current is adjusted via the pot(entiometer) on your drivers. Clockwise increases, counterclockwise decreases - I run mine with the pot at about 2 o’clock, which supplies the motors with a lot of current. Try 12 o’clock and below if you want to reduce idle whine.
Pololu drivers have a thermal shutdown, which keeps them from blowing up due to an overcurrent situation. Nema 17 motors don’t spontaneously blow up, but should be kept below 100C - if they instantly boil a drop of water, they’re too hot. More generally, they shouldn’t be too hot to touch for a second.
Also, if you decrease the stepper disable time in your firmware, you’ll hear much less of the whining - 30 seconds seems to be a good value since you have to keep in mind that steppers might lose their position when you turn them off.
Thomas, I notice on mine all the pots tune differently. One in particular is near impossible to move less than .3 volts at a time. I feel pretty confident in saying blindly turning those to ‘2 oclock’ is likely to end poorly long term.
Thanks you, you guys i would be lost with your help. I’m looking into how to calibrate this things right know. I am seeing to turn it down tell the motor tell the motor vibrates and move it up tell the wining stops. Addidis you saying to measure the voltage from the pot to ground using a DMM. I’m just happy that I know have a Idea what is making the noise.
Yep there was a nice video on youtube I found. LEme grab a link it was a pain to find. Definately dont just turn those. BAd things will likely happen.
Thank you so much Ill be doing this later tonight when I get home
@Addidis_no my tuning procedure is fairly simple, really: since I have 2.5A motors and fans blowing over the drivers’ heatsinks, I just turn them up until the driver’s thermal protection kicks in, then turn them back down a bit.
I’m running a fairly heavy custom Mendel90 and I need every bit of torque the drivers can provide. The o’clock position was just a rough guide after all.
But you’re right, using a voltmeter really is the proper way of doing it.
Take your time. Lets pretend you have pla motor mounts. Mistune these and they melt. There are tons of variables that can play into this that we havent gone over. Your motors may or may not handle what you try to put in.
For people who know what they are listening for its probably trivial to set by ear. If not you can have a bad day trying. MElted parts, burnt drivers, the list is long.
PLA on any parts that touch a motor is just asking for trouble…
So after adjusting them to 0.4v I still have the same noise it did get little quieter though. I did try turning them all the way down and it seemed to turn the noise off. Also tried going a little under 0.4v
yeah .4 isnt the goal, the goal is as low as you can get it with it printing right.
ahhh now its set right sounds like music to my ears
If you turn them all the way down, you’re effectively reducing the steppers’ current to zero - your printer won’t even try to move its axes on this setting.
The whine is an inherent issue with chopper-type stepper drivers (which is the most common and energy efficent design nowadays) - it’s the same chirping/whining some power supplies emit. If it really bothers you, you’ll have to swap out your drivers for something like the linistep.