E-Steps
Extruder steps per millimeter — how many motor steps the extruder needs to push exactly 1mm of filament. The foundation of all extrusion accuracy.
Critical priority
Printer-Specific
What It Is
E-steps (extruder steps/mm) defines how many stepper motor steps are needed to advance exactly 1mm of filament. If this value is wrong, every print over- or under-extrudes regardless of all other settings.
What It Controls
- Total volume of plastic deposited per move
- Baseline accuracy for flow rate, pressure advance, and retraction
- Dimensional accuracy of printed walls
Why It Drifts
- Extruder gear wear (teeth dull → less grip per step)
- Switching extruder hardware (different gear ratio)
- Filament diameter variation (indirect — affects effective flow)
- Drive tension changes
How to Calibrate (Manual)
- Mark filament 120mm above the extruder inlet
- Command
G1 E100 F100(extrude 100mm slowly) - Measure remaining distance from mark to inlet
- Calculate:
new_e_steps = current_e_steps × (100 / actual_mm_extruded) - Apply with
M92 E<value>, save withM500
How the Auto-Tuner Calibrates It
- Roller encoder on filament path measures actual mm fed vs. commanded mm
- Calculates correction factor automatically
- Can monitor continuously during prints for drift detection
Related Anomalies
- Under-extrusion — E-steps too low
- Over-extrusion — E-steps too high