Going mad this afternoon.

Going mad this afternoon. Been a while since I messed with my Eustathios, yesterday got a PEI sheet laminated to my glass and ran through tramming the bed with the piece of paper and many repetitions method.

Went to do some prints this morning, and I notice that the first layer is excessively squished. Now I measured the paper I trammed the bed with to 0.1mm so I set the Global G-Code offset in the Z-Axis in Simplify 3D to -0.1mm to compensate. This should in theory mean that a zero in the slider will result in the head being precisely at the surface of the PEI right?

Checking the gcode I see that the first layer is being printed at Z0.092mm as I would expect, meaning total distance of the head is 0.192mm from the bed (my layer height). However the first layer is clearly way too close to the bed.

Obviously I can just mess with my Z-Axis offset to fix this, but I’m trying to understand where my logic has failed here. Any ideas?

You know I think I just realized why this isn’t working as expected. I trammed the bed without heating the nozzle, I did heat the bed, but completely overlooked the nozzle temperature, which obviously is a pretty large influence on expansion since its much hotter. D’oh!

I’ve personally given up logic when considering the first layer after playing with different slicers. Instead, I adjust it to achieve the optimal height according to appearance during printing, measure the total height of the print after, and make changes from there. So long as your Z-steps are correct, a 0.05mm change in your true z-axis starging height likely won’t make a difference in the functional part but will definitely be obvious in the first layer quality.