Backlash Compensation
Mechanical play in the motion system — the small amount of 'lost' movement when an axis reverses direction.
Low priority
Printer-Specific
What It Is
Backlash is the mechanical slack in the drivetrain — when an axis reverses direction, the first fraction of a millimeter of motor rotation is taken up by play in gears, belts, or leadscrews before the carriage actually moves. Backlash compensation adds extra steps on direction changes to cancel this.
What It Controls
- Dimensional accuracy on direction reversals
- Circle roundness (circles become ovals with backlash)
- Hole accuracy (holes print undersized)
Why It Drifts
- Belt stretch increases play
- Leadscrew nut wear (Z-axis)
- Bearing wear
- Loose anti-backlash hardware
How to Calibrate (Manual)
- Mount a dial indicator against the carriage
- Command a known move in +X, record indicator reading
- Command same distance in -X, record reading
- Difference = backlash value
- Enter backlash compensation in firmware
How the Auto-Tuner Calibrates It
- Dial indicator + direction reversal measurement — automated measurement sequence
- Measures all axes systematically
- Low priority: modern belt-driven printers have minimal backlash
Related Anomalies
- Backlash Artifacts — visible surface artifacts from uncompensated backlash