Repetier Firmware: h-gantry + steps-per-mm

Hi,

I am testing a classical h-bot gantry with the Repetier-Firmware.

So far, the movement direction and the endstops are working fine. However, the movement distance along the X and Y axis is not correct:

eg. command G1 X200 makes the extruder move only around +170mm in the X-direction. G1 Y200 moves the extruder only around +170mm in the Y-direction.

Settings (double checked in EEPROM):
XAXIS_STEPS_PER_MM 160
YAXIS_STEPS_PER_MM 160

I use GT2 (2mm pitch) pulleys with 20 teeth. This yields 80steps/mm for a stepper with 1.8deg/step in 1/16 microstepping mode. According to comments in the Repetier-Firmware: "For xy gantry use 2*belt moved!", which I understand as using 80*2=160 for the number of steps per mm in the settings.

How do I get the correct distance travelled along the X and Y axis?

I would be thankful to any comments and help!

Maybe this site can help: RepRap Calculator

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3D Printing :: bit-by-bit - Thingiverse

Thanks, I did that. The result is the same: 80steps/mm.

I wonder if I have some misunderstanding of the settings in Configuration.h for steps per mm for an H-gantry. Maybe I am missing something else, here...

I hope someone has an idea here.

Check the MAX_LENGTH. Here are the default settings:

// maximum positions in mm - only fixed numbers!
// For delta robot Z_MAX_LENGTH is maximum travel of the towers and should be set to the distance between the hotend
// and the platform when the printer is at its home position.
// If EEPROM is enabled these values will be overidden with the values in the EEPROM
#define X_MAX_LENGTH 165
#define Y_MAX_LENGTH 175
#define Z_MAX_LENGTH 80

And remember to change the EEPROM_MODE to a different value.

Otherwise try G1 X100 or G1 Y100.

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3D Printing :: bit-by-bit - Thingiverse

Thanks, MAX_LENGTH values are correct. The device is homed with at x_max and y_min. The same problem persists even for G1 X10 or G1 Y10.

EEPROM_MODE is set to 1. I can change EEPROM constants in Repetier-Host and this works.

Where else could the problem be?

If you don't mind, you can upload your Configuration.h (Attach a file > Choose File > Attach).
I'll compare (OS X > FileMerge) your configuration with mine.

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3D Printing :: bit-by-bit - Thingiverse

I have found the problem. It was a bad solder joint on the stepper pin. I guess I should have checked the electrics before bothering with questions about firmware. Thanks for offering your help!

Okay, although I don't catch why this has affected both X and Y axes.

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3D Printing :: bit-by-bit - Thingiverse

I appologize for my last post - it was intended as an answer to another question in another forum.

The problem with the X/Y movement was indeed related to EEPROM settings, and to MAX_LENGTH in particular. I have checked EEPROM settings again, and these were messed up for some reason (0 or 255 values for some of parameters). After uploading the firmware again, the problem was solved. Thanks again for help!