Ender 3 extruder calibration ruler

thingiverse

My first 3D model on Thingiverse, I hope you find it useful. When calibrating the extruder it can be awkward getting at the extruder to accurately measure and mark the filament, so I created this custom ruler. It can slip in against the extruder housing and there is a 2mm groove for the filament to sit in while you mark 100mm and 120mm. Then use the control panel on the printer to move extruder axis 100mm, and use the ruler a second time to see whether your esteps are correct or need resetting. The calculation for new esteps value is (existing esteps x 100)/ new esteps from the calibration ruler. From what I have read, it is recommended to do this calibration test three times to make sure you have the right values set.