Hi folks. I brought my Vertex K8800 back to life 
. Tested printing with the Vertex keychain and it looks sweet!
Ok, time to print spare parts for my dad. I’m trying to teach my father how to draw in Fusion and slice the objects.
The Printer was after first test about 30min in idle/pause.
After slice and sent to printer, the problem started. Idk why, but the delta have now a z offset about ~5mm. We didn’t change anything. I tried multiple times calibration procedure. No success. Checked the end stops and piezos. There were Ok.
Two simple modes are added.
-Better belt tensioner
-Filament guide.
In Calibrate Z, I can’t save the setting. Neither can’t go lower as 2.2.
Any suggestions making this issues?