Pinda Setup Jig

Recently I had an issue with my X-axis that involved a lot of disassembly and re-assembly and re-calibration runs. Never fun but sometimes necessary.

One of the things that has bothered me is that the first layer cal was so dependent on the relative height of the PINDA sensor and yet the PINDA sensor was set using a “zip tie” which has a variable thickness. That variability means that the value you set with the first layer calibration can be quite variables (I've had -0.6mm to -1.88mm on different times.) So I decided I wanted to eliminate variability here and created this simple model as a setup fixture (or jig). 

Usage is straightforward, loosen your PINDA, manually lower the Z axis to the point where the hot end nozzle touches the wide area, then lower the pinda to rest on the 10 mm “raised pad”.

The pad is 1mm thick so it creates a 1mm difference between the PINDA height and the hotend. When I use this, the correct first layer offset is always -1.500 +/- .020. That lets me rapidly get the printer set up after replacing the nozzle (or after re-doing calibration). I've asked a machinist friend of mine to make one out of aluminum because if the nozzle is hot it will melt this test fixture as seen in the picture :-).