Observations: After following the procedure to adjust z-axis with offset, moving the ir sensor and using 5cm of belt, the print head is still about 5mm from the surface after auto home. As move the print head from left to right, the distance between the print head and the glass changes by about 1mm even after auto leveling. One print head is lower than the other by about 1mm - do I need to loosen the grub screws and pull the heat sink out of the print head printed part a little? I assume when I tighten the grub screws again, the print heads will be snugged up and one will be shorter again - haven't tried it yet. After auto home, Y is at 100 and X is at 175. Expected X to be at 150 but maybe this is for single print head system.