First Layer Experiments

This is an experiment that I ran on my Anet-A8. I was keen to know how critical the Z-gap was for the first layer of the print head above the build board. I had gone through the usual build board levelling procedures a few times and was happy the heated bed was level. However I was suspicious that every time I swapped filaments, handling the print head (squeezing the pressure idler wheel lever) caused some change in the head clearance, mainly effecting the first layer and causing "random" problems with adhesion.

I had fitted a Z-Stop adjuster (Babarikado, https://www.thingiverse.com/thing:2703393) and was able to use a Philips Head screw driver to make adjustments. Sadly most sides of a Philips Head screwdriver look alike once it begins to turn and I wanted something I could use for some more quantitative testing. I looked up M3 threads and found they have a pitch of 0.5mm, so two complete turns should be 1.0mm. To this end I designed a small 5 sided knob (each side=0.1mm) for the Z