Welcome to the SeeMeCNC Community

My apologies if this has been answered before, but I can't find it.

I just upgraded my Rostock V1 with Repetier 0.91 firmware downloaded from SeeMeCNC's Github. It seemed OK until I tried calibration.

Sending G28 from the console in MC it went to the top just like I expected. I then followed the procedure in the manual to set the Z height…so far, so good until I looked at the new Max Z height written into the EEPROM…719.54 mm. Previously, it was about half of that. I tried lowering it with a console command, but that crashes it into the build plate. I moved it to X90 and it only moves about half of that. Clearly something is amiss.

I was previously having good success with Repetier 0.82

Any ideas? Thanks in advance.

When you set the overall z height from the LCD, you need to home the towers before manually lowering to the appropriate Z-Height.

Make sure you are disconnected from MaterControl when you set it via the LCD on the printer.

LCD:
1. Home Towers
2. Z position ( lower to correct height)
3. Set new Z



I hope I'm understanding the issue correctly.

Looks like you need to change your steps per mm,,,, The older boards only use half of the microstepping of the later version boards.

Open up your congiuration.h file, and in the first 130 lines are the changes you'll need to make,,,,, I assume you'll have to change the pulley tooth count from 20 to 15, and you'll have to change micro_steps from 16, to 8. I am not sure about changing the pulley diameter.

I'm pretty sure the pulleys are 20T, I recently changed to the all aluminum ones and it was working fine that way.

The micro_steps being a 2:1 ratio, it makes sense that it would double the Z-height that the machine thinks it's at.