Calibrate KLipper extruder step-distance

Preparation:

1. Mark the filament 150mm before the entry to your extruder.
2. Heat up the nozzle to your desired printing temperature.
3. Home all axis to get in "printer ready" state.
4. Move the nozzle away from the bed to make room for the filament that will be extruded in a moment.
5. Execute the following G-commands one by one.
   • G92 E0 (resets the "extruded material" value to 0.)
   • G1 E100 F100 (extrudes 100mm filament with 100mm/min.)
6. Now measure the distance between your extruder entry and the mark on your filament.

If it is 58mm instead of 50mm (150mm - 100mm) then you are UNDERextruding by 8mm. This make E = 92 mm in the formula below.
If it shows 45mm than your are OVERextruding by 5mm. This makes E = 105 mm in the formula below.

Now calculate:

E = measured length of extruded filament.
d = desired/expected length of extruded filament.
C = current step_distance.
n = new valu for step_distance.

n = (E/d)*C

 (92 / 100) * 0.0105 = 0.00966
 (105 / 100) * 0.0105 = 0.011025

Or use this App

 https://studio.code.org/projects/applab/7Mz-Jt-Gy6HG5veaWxx5j9Zz0w_6pDnEqFoxZPUYCec

Notes

For underextrusion the new value is lower (0.00966) than the old one (0.0105), and for overextrusion it is the opposite ;-)

__________________

• https://mattshub.com/blogs/blog/extruder-calibration
• https://docs.google.com/spreadsheets/d/1AWBTYIDA7LRxIdVeTuUnIcgW5g1HijDb/edit#gid=627601536
• https://github.com/KevinOConnor/klipper/issues/934#issuecomment-714438327