PROJECT: K40 automatic bed lift. Is it possible to run a NEMA 17 motor forward and backward without a controller board . Would like to use a momentary switch. Basically apply voltage to both sides of stepper. Not controlled by computer. Thank You. Bob Hall
No. Steppers work by cycling back and forth between the A and B coils and you can’t do this with a solid current. If you’re looking for a minimalist solution this can easily be done with an Arduino and stepper driver.
Here is an arduino based one that could be used/modified. The code is in the downloadable files. K40 Laser - Arduino based adjustable "Hub Table" Panel with OLED Display and LED powerpanel by Printcontrol