I have built a cnc with Nema 17 motors. it is controlled by an Openbuild Blackbox. with the external adjustment of volts for the motors. but either the motor stands like it squeaks (easy to hear with a screwdriver on the motor and the ear) and if I turn the volt so it goes away then the motor starts and drives around inside. It does not move on the shaft, but sounds like a jet engine during start-up, again with a screwdriver in the ear Sometimes I can actually hear that whistling sound - howling sound. the motors are at a 48 - 52 degrede when they have been on for some time When I do the same thing on one of my 3d printers, the motors are totally silent. what in the world can it be ??
If its a rattling sound (not a smooth hum): See See docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation] For nema17s current adjustment is almost all the way counterclockwise (it starts at 1.1A on the minimum side) Warm steppers are good - just shows you how underpowered 3D printers run their motors - and thus why so many have skipping problems. Warm yes, burning your hand - no. Adjust accordingly You'll never have silent motors on a CNC - We need high torque - heavier loads than a 3D printer
Thank you for your answers. it is when the cnc is stationary, but of course powered on I try, to make it easier to hear, to put a screwdriver on the motor - ear, and have tried to adjust the volt, but can not adjust so it does not growl / scratch or howls. It's not a hum it says. It's actually the openbuild manual I used to find pairs on engine. motor, it is all motors, but mostly on the Y axis. And should almost be "luck" if I can mount 4 engines incorrectly Moreover, there are no problems with them driving in random directions etc. Whether it is Nema 17 or Nema 17 C I do not know. Do not know the difference. Can engines be worn / damaged, perhaps due to overload, but still running ? I do not have ground in my house power, do not know if that may be the reason? simple it is mysterious
Then that's all good and working If you need the screw driver to hear the noise, you are obsessing over nothing. Stepper motors are controlled with a varying pseudosinewave power signal - audible noise is normal and a good sign.
