Bed Level Correction Limitation -50 Microns; I need -80 Microns  

Bed Level Correction Limitation -50 Microns; I need -80 Microns

Hello to All,

I’m very new to the 3D Printing World and have struggled with First Layer Calibration and Bed Leveling from the receipt of my Original Prusa i3 MK2 printer a month ago.

The Problem:
The print bed is not flat. The backside needs to be adjusted so the nozzle is closer than -50 microns. To overcome the -50 microns firmware limitation, I adjust the g-Code Starting Script as follows: G80 L0 R9 F12 B-80. Once the g-code starting script was modified, I reset the firmware Bed Level Correction to all zeros (i.e., Left 0 Right 0 Front 0 Back 0). The reason I reset the Bed Level Correction settings to zero was, I thought the g-code starting script would make the necessary adjustments in place of the firmware. However, when I ran the starting script, mesh bed leveling ran normal but there was no indication of the parameters associated with G80 (e.g., L0 R9 F12 B-80) being executed. In review of my starting script, I don’t see anything that may cancel-out the G80 parameters. Currently, the only way I can adjust for bed leveling is to use the firmware Bed Level Correction that limits me to -50 microns. However, I need -70 to -80 microns for the backside of my print bed.

Additional Details:
After performing the XYZ Calibration and reset many times, I went through my printer ensuring all the screws and nuts were tight, rods were seated and flush, zip ties secured, everything is aligned, etc. followed by more XYZ calibrations to no avail.

1. What am I doing wrong?
2. When I modify my g-code starting script with G80 L0 R9 F12 B-80, should I reset the firmware Bed Level Correcting settings to zero? This is what I did but the g-code G80 parameters didn’t execute…it was as though I had done nothing.
3. Why can’t I get the g-code starting script (e.g., G80 L0 R9 F12 B-80) to run? My current Starting Script is as follows:

M115 U3.0.7 ; tell the printer latest firmware version available
G28 W ; home all without mesh bed level
G80 L0 R9 F12 B-80 ; mesh bed leveling
G1 Y-3.0 F1000.0 ; go outside printing area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line

4. If the PINDA Probe is responsible for Auto Leveling the print bed, is my PINDA Probe defective since I need to manual adjust the bed level?
5. Any thoughts that may help?

Any and all help is sincerely appreciated. Thank you!!!