Input Shaping Explained: Faster 3D Printing Without Ringing
What ringing is
Look at a fast 3D print and you will often see faint repeated waves on the surface near sharp corners. This is ringing: the toolhead's mass and the frame's flex cause vibration that the structure echoes back into the print. The faster you print, the worse the ringing.
What input shaping does
Input shaping pre-modifies the motion commands so that the natural resonance frequency of the printer is cancelled out as the move starts and stops. The toolhead still moves at the commanded speed, but the vibration is mathematically nulled. The result is clean surfaces at much higher speeds than would otherwise be possible.
How to calibrate input shaping
- Klipper: attach an accelerometer (ADXL345 or similar) to the toolhead, run RESONANCE_TEST X and RESONANCE_TEST Y, Klipper picks the shaping curves
- Marlin: Marlin 2.x has M593 commands; calibration is via test prints rather than accelerometer
- OrcaSlicer: includes input shaping calibration tests under the Calibration menu
Filament considerations for high-speed printing
Input shaping unlocks higher speeds, but the filament still has to keep up. Standard PLA struggles above 200 mm/s. Use high-flow / high-speed PLA, dry your filament, and upgrade to a high-flow hotend (Revo, CHT, Volcano) to take full advantage.