3-axis printer dimension calibration and supporting documentation

thingiverse

This is an accurate solution for calibrating your printer's steps/mm for X, Y, and Z (but not E). Everything isn't actually bigger in Texas, all measuring devices are incorrectly calibrated in Texas. And if you think that's funny, then this is the right post for you, fellow standards enthusiast! Most printer dimension calibrations rely on a single measurement. This can be biased by your extrusion parameters and z-offset/bed leveling. For instance, overextruding will add just a little too much flow to the walls, making them thicker, which will change the dimensions of the cube, but not the steps/mm. The same wall thickness offset is present for a 1cm cube or a 10cm cube. Instead of printing a >10cm cube and hoping over-extrusion is negligible, take multiple measurements on a smaller calibration standard. By taking multiple measurements and performing a linear fit, you can extract the slope, which is what you actually want when calibrating steps/mm. This print is a stack of 1cm cubes, providing measurements for 1cm, 2cm, and 3cm for X, Y, and Z. I've also oriented the STL and included X and Y labels so you know which axis you're measuring for easy access. Because linear regression can be a pain, I've included an excel worksheet and a python script that will do the math for you! Just input your measurements (they don't even have to come from this object) and your current printer settings and it will spit out your new steps/mm! Note, make sure to level your bed well before calibrating or else the Z calibration can be inaccurate. UPDATE 9-6-2019: Found a major error in the code, download again if you used the scripts prior to this update.