settings for steps per unit in marlin

Does anyone know how to set up steps per unit in marlin configuration.h for 3d printer?

I'm doing calibration for the x-axis stepper motor but having problems setting the correct steps/mm.
I'm Using
  • marlin 1.8.13
  • RAMP 1.4
  • Arduino Mega 2560
  • DRV8825 (set to 0.85V with all 3 jumpers)
  • stepper motor (1.7A, 1.8 degrees, 200 turns/rev)
  • M8 Leadscrew, pitch 1.25mm/rev
base on the prusaprinters calculator (
I suppose to change it to

#define DEFAULT_AXIS_STEPS_PER_UNIT   {2560, 2560, 2560, 190 }

but here is the thing, my motor stops turning with a high pitch noise, and drv8825 extremely hot when it goes higher than 400 steps/mm. I assume it is too fast for it to spine since when I set it to 80 steps/mm it moves very slow.

when I input
 #define DEFAULT_AXIS_STEPS_PER_UNIT   {160, 160, 160, 190 }
x-axis only moves 20mm when I set to move 100mm in pronterface.
I change it base on the formula (desired length / actual length * current steps per unit), which I got (100/20*160=800 steps/mm) it is still too much for the motor to function properly.

below are my current settings

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 160, 160, 160, 190 }
 * Default Max Feed Rate (mm/s)
 * Override with M203
 *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
#define DEFAULT_MAX_FEEDRATE          { 300, 300, 5, 25 }

 * Default Max Acceleration (change/s) change = mm/s
 * (Maximum start speed for accelerated moves)
 * Override with M201
 *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
#define DEFAULT_MAX_ACCELERATION      { 3000, 3000, 100, 10000 }

extruder E0 works fine, very precise.
Any suggestions? Really appreciate  :)


  • > x-axis only moves 20mm when I set to move 100mm in pronterface.
    Then you need 800 for xy. Z is often higher when it is a Leadscrew.
    But also note that RAMPS is slow and going higher that maybe 40000Hz will make it fail to get clean signals. Not sure where marlins limit with that processor is. But with 800 steps/mm that many max. feeddrate is 40000/800 = 50mm/s.
    On leadscrews the extra friction also reduces maximum feedrate.

    That is more general so hope it helps. For marlin questions  this is wrong forum after all:-)
Sign In or Register to comment.