CoreXY 'Microcube' Printer, Z drops

Eddiie

Hello,

I am trying Repetier firmware on a home made corexy, "microcube" printer.   When sending a file to print, everything heats up, homes, gets ready to print, but rather than raising the bed toward the hotend, it drops another 10mm and then the hotend starts to print...

What am I doing wrong?  I cannot seem to figure it out.

Homing works fine...

Repetier

What does

G28

M114 ; to see what printer thinks where it is see log output

G1 Z1

do?

Start with simple steps you know what is happening. Then check the gcode you send on print start and replay it to find where the drop happens and tell us the gcode where it happens. It could be in gcode or something else not working right.

Eddiie

oh you are right.  There was a drop Z 15mm in the GCode, I guess you want that on a different type printer but not a corexy.

Thank you for pointing me in the right direction.

Question:  Steps/mm and acceleration settings in one firmware should be the same in Repetier, correct? 

I have the following settings and the motors move at a very high rate and go about 75% of the way to the max x max y settings - 

#define XAXIS_STEPS_PER_MM 66.5  //nema17 1.8 degree

#define YAXIS_STEPS_PER_MM 66.5  //nema17 1.8 degree

#define ZAXIS_STEPS_PER_MM 40758  // 28byjj

#define EXT0_MAX_ACCELERATION 20

#define RAMP_ACCELERATION 1

#define MAX_ACCELERATION_UNITS_PER_SQ_SECOND_X 150

#define MAX_ACCELERATION_UNITS_PER_SQ_SECOND_Y 150

#define MAX_ACCELERATION_UNITS_PER_SQ_SECOND_Z 1

#define MAX_TRAVEL_ACCELERATION_UNITS_PER_SQ_SECOND_X 150

#define MAX_TRAVEL_ACCELERATION_UNITS_PER_SQ_SECOND_Y 150

#define MAX_TRAVEL_ACCELERATION_UNITS_PER_SQ_SECOND_Z 1

#define INTERPOLATE_ACCELERATION_WITH_Z 0

#define ACCELERATION_FACTOR_TOP 100

Repetier

For normal core xy you need to multiply steps per mm you think with 2 or sqrt(2) not sure about which one. There is also an inofficial FAST_COREXY mode where steps are as you think and that should be able to move faster, but uses nonlinear settings for movement also move is still linear.

Repetier

What did you mean same as in repetier? Steps are only set in firmware. Server uses acceleration for internal time estimations. EEPROM editor show what firmware is set to so you can modify without recompiling.