Z-Offset Calibration

Update Feb 3, 2026: I have updated the script and the 3mf file to now include positive Z-Offset calibration as well. This can now be used to calibrate from -0.1mm to +0.1mm. I will be adding more plates to allow more file tuning of your offset. The final product will probably have somewhere around 23 plates. 1 for testing negative offsets, one for positive offsets, and one each for steps of 0.001 for in-between the steps that are currently available. An example would be that if say +0.02 and +0.03 both look really good, There would be a plate for testing the values in-between those to REALY dial in your machine. This is going to be quite tedious work, but look forward to the full selection of plates in the next week or two. I am planning on grinding it all out this weekend so i can update this ASAP. Since the 2.6.0.0 Kobra S1 firmware update, something seems to have broken the leveling on my S1. I was getting instant blobs at the start of prints, filament not sticking to the bed, etc. Scratched my head for hours before i found out that it was the Z-Offset. To fix this, I made this simple python Post-Processing script that can be called from Process > Others > Post-Processing Scripts. The script will automatically take the base z-offset value from the generated GCode file, and then modify only the Z values by a predetermined amount per specific object. I recommend that you set the z-offset value under Printer Settings > Basic Information > Z Offset to 0 before trying to print. I have set this up to test z-offset values from -0.1mm to -0.01 mm. If you need to, you can also delete the objects on the plate that you don't need, and this script will work perfectly fine. To make this work, save the z_offset_calibration_script.py to a known location (i recommend inside the slicer files, or your documents folder. You can also just keep it in the download folder after you extract it, it will still work just fine). Look for the python executable (.exe) on your pc (possibly C:\