Motor Steps/mm configuration

Hello,
I have a Prusa i3 R2 with Motech motors Nema 17 1.8° 4,4kg, Ramps 1.4, Drivers DRV8825, belt GT2 step 2mm, pulley with 20 tooth.

In repetier firmware i used tihs configuration:

#define XAXIS_STEPS_PER_MM 80
#define YAXIS_STEPS_PER_MM 80
#define ZAXIS_STEPS_PER_MM 3200

and also  

#define X_MAX_LENGTH 200
#define Y_MAX_LENGTH 200
#define Z_MAX_LENGTH 210
#define X_MIN_POS 0
#define Y_MIN_POS 0
#define Z_MIN_POS 0

(a friend with the same hardware sent me this configuration and it works properly with his printer).
Using repetier calculator, the numbers should be ok (80) for X and Y.

I launched Repetier host and I clicked on HOME-X button and the extruder went correctly on the left side to the endstop and stopped setting the point X=0.

Then i clicked on the X button to move to the right side with number 50 for 4 times and the extruder reached the center of the X axis instead of the end and the X coordinate is X=200 and it's wrong because it's in the middle instead of the end of te right side.
If I click more than 4 times on X button the extruder doesnt't move on right side (I think because in the configuration I have correctly #define X_MAX_LENGTH 200 and it think to be at X=200 instead of X=100).

Why it happens?

80 steps should be te right number with my hardware.

Thank you,
Roberto

Comments

  • Check steps per mm defined in eeprom. If that matches remove stepper driver and see if you have set the right microstepping there.
  • This is what I see if I use Gcode M 205 and it seems to be OK...

    19:21:19.573 : EPR:0 1028 4 Language
    19:21:19.578 : EPR:2 75 115200 Baudrate
    19:21:19.582 : EPR:3 129 0.000 Filament printed [m]
    19:21:19.582 : EPR:2 125 0 Printer active [s]
    19:21:19.586 : EPR:2 79 0 Max. inactive time [ms,0=off]
    19:21:19.591 : EPR:2 83 360000 Stop stepper after inactivity [ms,0=off]
    19:21:19.593 : EPR:3 3 80.0000 X-axis steps per mm
    19:21:19.599 : EPR:3 7 80.0000 Y-axis steps per mm
    19:21:19.604 : EPR:3 11 3200.0000 Z-axis steps per mm
    19:21:19.608 : EPR:3 15 200.000 X-axis max. feedrate [mm/s]
    19:21:19.610 : EPR:3 19 200.000 Y-axis max. feedrate [mm/s]
    19:21:19.610 : EPR:3 23 2.000 Z-axis max. feedrate [mm/s]
    19:21:19.615 : EPR:3 27 40.000 X-axis homing feedrate [mm/s]
    19:21:19.619 : EPR:3 31 40.000 Y-axis homing feedrate [mm/s]
    19:21:19.623 : EPR:3 35 2.000 Z-axis homing feedrate [mm/s]
    19:21:19.627 : EPR:3 39 20.000 Max. jerk [mm/s]
    19:21:19.632 : EPR:3 47 0.300 Max. Z-jerk [mm/s]
    19:21:19.632 : EPR:3 133 0.000 X min pos [mm]
    19:21:19.634 : EPR:3 137 0.000 Y min pos [mm]
    19:21:19.638 : EPR:3 141 0.000 Z min pos [mm]
    19:21:19.645 : EPR:3 145 200.000 X max length [mm]
    19:21:19.645 : EPR:3 149 200.000 Y max length [mm]
    19:21:19.647 : EPR:3 153 210.000 Z max length [mm]
    19:21:19.651 : EPR:3 51 1000.000 X-axis acceleration [mm/s^2]
    19:21:19.656 : EPR:3 55 1000.000 Y-axis acceleration [mm/s^2]
    19:21:19.660 : EPR:3 59 100.000 Z-axis acceleration [mm/s^2]
    19:21:19.664 : EPR:3 63 1000.000 X-axis travel acceleration [mm/s^2]
    19:21:19.668 : EPR:3 67 1000.000 Y-axis travel acceleration [mm/s^2]
    19:21:19.673 : EPR:3 71 100.000 Z-axis travel acceleration [mm/s^2]
    19:21:19.675 : EPR:3 1024 0.000 Coating thickness [mm]
    19:21:19.679 : EPR:0 880 0 Autolevel active (1/0)
    19:21:19.686 : EPR:0 106 0 Bed Heat Manager [0-3]
    19:21:19.688 : EPR:0 107 255 Bed PID drive max
    19:21:19.688 : EPR:0 124 80 Bed PID drive min
    19:21:19.692 : EPR:3 108 196.000 Bed PID P-gain
    19:21:19.697 : EPR:3 112 33.000 Bed PID I-gain
    19:21:19.697 : EPR:3 116 290.000 Bed PID D-gain
    19:21:19.701 : EPR:0 120 255 Bed PID max value [0-255]
    19:21:19.706 : EPR:0 1020 0 Enable retraction conversion [0/1]
    19:21:19.710 : EPR:3 992 3.000 Retraction length [mm]
    19:21:19.712 : EPR:3 1000 40.000 Retraction speed [mm/s]
    19:21:19.716 : EPR:3 1004 0.000 Retraction z-lift [mm]
    19:21:19.721 : EPR:3 1008 0.000 Extra extrusion on undo retract [mm]
    19:21:19.725 : EPR:3 1016 20.000 Retraction undo speed
    19:21:19.729 : EPR:3 200 620.000 Extr.1 steps per mm
    19:21:19.729 : EPR:3 204 50.000 Extr.1 max. feedrate [mm/s]
    19:21:19.734 : EPR:3 208 20.000 Extr.1 start feedrate [mm/s]
    19:21:19.738 : EPR:3 212 5000.000 Extr.1 acceleration [mm/s^2]
    19:21:19.742 : EPR:0 216 3 Extr.1 heat manager [0-3]
    19:21:19.747 : EPR:0 217 230 Extr.1 PID drive max
    19:21:19.751 : EPR:0 245 40 Extr.1 PID drive min
    19:21:19.753 : EPR:3 218 7.0000 Extr.1 PID P-gain/dead-time
    19:21:19.753 : EPR:3 222 2.0000 Extr.1 PID I-gain
    19:21:19.757 : EPR:3 226 40.0000 Extr.1 PID D-gain
    19:21:19.762 : EPR:0 230 255 Extr.1 PID max value [0-255]
    19:21:19.767 : EPR:2 231 0 Extr.1 X-offset [steps]
    19:21:19.771 : EPR:2 235 0 Extr.1 Y-offset [steps]
    19:21:19.771 : EPR:2 290 0 Extr.1 Z-offset [steps]
    19:21:19.776 : EPR:1 239 1 Extr.1 temp. stabilize time [s]
    19:21:19.782 : EPR:1 250 150 Extr.1 temp. for retraction when heating [C]
    19:21:19.786 : EPR:1 252 0 Extr.1 distance to retract when heating [mm]
    19:21:19.791 : EPR:0 254 255 Extr.1 extruder cooler speed [0-255]

  • Yes it is set to 80 steps per mm, but you driver is set to 32 substepping I guess. So increase to 160 or change microstepping to 16.
  • Ok, now it works (thank you) but I have another problem...

    As you can see the Z max lenght is 210 but it stops at Z=100 and I don't understand the reason.
  • How you can see thad substepping =32
  • @sns5400 you can conclude from theoretical resultion to measured, or you check the substepping pins of your driver and read what that pin combination has as substepping.

    @bebbbo Assuming your steps per mm are correct that makes in deed no sense. What does M114 report there and what does M119 say? Maybe z max end stop triggered?
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