There is an Error in the calculation of the new_rotation_distance in the Tuning Chapter Extruder Calibration

[iTzMtrx]

Hey, I think there must be an error in the calculation of the new rotation distance. There is a difference between the calculations of Klipper Marlin and RepRapFirmware. I dont know if this is intended, but I just wanted to make sure, that it is correct or gets corrected.

[brymck1]

I think it's different in the way it's calculated for Klipper, as I think the rotation_distance value is how many MM is pushed with one rotation, as when I made it larger it pushed less filament through...so it may not need correction, but I think the issue is I did the difference, not the actual extrude distance when first running through and noted that was way off.

I thought it was wrong as well because I did the extrusion difference (2mm) not the actual extrude distance in my first calculation...not enough coffee yet :)

[dowatugkins]

The math should be actual_distance/expected_distance. You are looking for a percentage of travel. You expected it to travel 100mm but got x instead. If x is say 101mm, 101/100 =1.01, or 101%, or if x is 99mm, 99/100=0.99 or 99%. The reprap and marlin formulas are wrong.