What This Helps You Do

Correct a Klipper extruder that over- or under-extrudes by calculating a new rotation_distance from a measured 100 mm extrusion test.

This is a manual-input workflow. It does not use live prices, uploaded model files, accounts, saved quotes, or external APIs.

Steps

  1. Heat the hotend to the normal printing temperature for your loaded filament so it extrudes freely without skipping.
  2. Mark the filament at a fixed reference point exactly 120 mm above the extruder inlet using a marker or tape.
  3. Command a slow 100 mm extrusion in relative mode: run M83, then G1 E100 F100. Keep speed low to avoid skipped steps.
  4. Measure how much filament actually moved. If you marked at 120 mm and now read 25 mm remaining, 95 mm actually extruded.
  5. Enter your current rotation_distance, the commanded 100 mm, and the measured value into the calculator to get the corrected rotation_distance.
  6. Edit printer.cfg with the new rotation_distance value, run FIRMWARE_RESTART, then repeat the 100 mm test to confirm. Iterate once more if the first correction was large.

Example Inputs

Current rotation_distance7.5 (example from printer.cfg)
Commanded extrusion100 mm
Actual extrusion95 mm (measured with ruler or calipers)

Example Outputs

Corrected rotation_distance7.125
Equivalent steps/mmShown if you enter full steps and microsteps

Formula

New rotation_distance = current rotation_distance × (actual extrusion / commanded extrusion). Example: 7.5 × (95 / 100) = 7.125. Direction is inverse to Marlin E-steps: under-extrusion lowers rotation_distance, not raises it.

Checklist

  • Heat the hotend to printing temperature before every test — a cold nozzle skips steps and ruins the measurement.
  • Use relative extrusion (M83) and a slow feed rate (F100) to avoid skipped steps during the test move.
  • Measure at the same reference point each time; do not re-mark between iterations.
  • Remember the direction: under-extrusion means lower the rotation_distance value (opposite of raising Marlin E-steps).
  • After confirming the extruder, calibrate flow rate from a single-wall print, then pressure advance.

FAQ

Is this a general 3D printing article?

No. This guide is tied to a calculator or template and includes concrete inputs, outputs, and a formula.

Does this guide use live prices or uploaded model files?

No. Use your own slicer values, prices, and shop assumptions. PrintCostCalc does not upload models or fetch live prices.