Im sure most people have stopped looking at this forum now but its worth a shot still.
I did have my printer running ok ish. i made some upgrades to the linear rails to make it run smoother. after putting the printer back together and recalibrating everything as per the set up guides. the printer still trys to print the first layer too high. about 0.5mm too high. i have managed one or two prints but putting an extra manual offset before printing but this isnt actaully fixing the issue.
i have tried recalibrating the z offset about 10 different times and still the same issue. has anyone had this problem and managed to correct it?
i dont think it is a mechanical issue as i replaced the stepper motor with the one i used for the 2nd extruder. So it must either be with th slicer or marlin. however the G.code looks fine to me. and i havent made any changes to marlin sinse the original set up.
For me, increasing the number of measurement points for the bed leveling and then turning on babystepping and really dialing in the Z-Offsite through the Tune menu while printing, I've been able to get the first layer working well.
Both of those things are in the configuration.h Marlin firmware.