Hi,
I am using Melzi board and Marlin firmware to control my 3D printer. Although I change the value in Configuration.h, upload to board, it does not make any difference. I checked again and again if I am changing the right value (I mean under the #ifdef REPRAPPRO_MENDEL2 and uncommented #define REPRAPPRO_MENDEL2) and it does not seem to be wrong. Can you guess where the problem is?

Do you have the EEPROM activated? If so, you need to manually send a "M502" to load the values from Configuration.h and then "M500" to store these new values in EEPROM. Otherwise the old EEPROM values will be continue to be used.

#define DEFAULT_AXIS_STEPS_PER_UNIT  {80, 80, 80, 760*1.1}  // default steps per unit

That´s the line where I always change steps/ mm.
Also you should send a M502 and M500, if you have EEprom enabled to read the new values and store them in EEprom.
-Olaf

I don't know how to enable/disable eeprom on code. I just download the current firmware code and change these configurations. I think this is the problem.

Thank you.