But couldn’t figure out where he got the value of 1.45V and it made my motors very loud if I set the pots that high.
After searching around a bit I found this seemingly sensible blog post on the subject:
I looked up the specs for my Kysans (1124090) and found them to be rated for 1.5A per phase and when I solved for Vref using the formula on Erl’s page (and 0.11 ohms for the sensing resistance) I get 1.32V, which still makes my motors a little loud and quite hot if I set the pots that high.
I like to set it by feel and sound. Turn the pots down, then slowly turn it up until the motors move. Turn it a little bit past that, and you’re done. Test with a few movements, if it stalls, turn it up a little more.
Yeah, that’s what I did originally, but I’m kind of partial to repeatability and particularly fond of putting a number to stuff (when possible) and it seems like there should be a way to do this “properly”, you know?
Well, you can do that method, then read the voltage and set all the rest. Besides, I think the amperage is max operating current, it might be better to run lower, say at 80%. Try that and see. 1.07v perhaps.
I usually try to stick to around 1 V - 1,45 sounds like it would make the motors scream. The principle of motor usage in 3D printers is underfeeding them
My tuning begins as @Stephanie_A suggests, then you just have to see how your motor performs during a print. If it skips - turn it up a bit, if it overheats - lower a bit. Monitor the temperature of the driver at the same time - 1,45V would make the chips hot even on idle.
Thanks to you both for your comments. I’m really hoping to scare up someone with the electrical engineering know-how to teach me a theoretical/practical way to do this. For example, if my X or Y axis has resistance that is being overcome by excessive voltage to the steppers, isn’t it possible I’m also overpowering the micro-stepping?
