comments:
newtekie1 posted on r/printers6d
I can't help you with the calibration issue. AFAIK, the label spacing detection is done with a separate sensor that detects the gaps between the labels. I also think there is a setting for how the detection is done that maybe gets changed when you switched the print heads? But I can tell you that I just bought this print head for my ZT410 and it was a drop in replacement and worked right away.