I have a large model to print so I have been trying to recalibrate my platform using 6.6.6 fw. I have got the settings to +0.21, +0.308, +0.301 and + 0.307 with the center 0. These measurements would either suggest that the center of the platform is lower. Is this likely or am I doing something wrong?
On the suggestion of one of the other owners, I took the PCB off the platform and there was a lot of ABS debris underneath and in excess of 0.2 mm off abs protruding through the bottom of the PCB mostly in the center.
At the very least I think you need to include in the maintenance instructions for the printer something about removing the PCB and cleaning out the debris.