High-Speed Printing: Input Shaping & Pressure Advance

For years, 200 mm/s was considered fast. Modern CoreXY machines and Klipper firmware now routinely print at 300 to 600 mm/s. The jump did not come from stronger motors alone. It came from software that compensates for the physics of fast motion: input shaping to cancel vibration, and pressure advance to keep extrusion consistent through accelerations.

If your fast prints show ghosting, rounded corners, or blobby seams, the fix is almost never just slowing down. It is calibration.

When a printhead changes direction quickly, the frame and gantry vibrate. Those vibrations print as faint repeating echoes next to sharp features, called ringing or ghosting. Input shaping measures your printer's resonant frequencies and shapes the motion commands to cancel them out.

Klipper and many modern firmwares support input shaping. The best results come from a one-time calibration using an accelerometer (such as an ADXL345), which prints a test and recommends a shaper type (MZV, EI, 2HUMP_EI) and frequency for the X and Y axes. Without an accelerometer, you can print a ringing test tower and tune by eye. Re-run calibration after major hardware changes, because added mass shifts the resonant frequency.

At high speed the extruder must push filament fast, then stop precisely. Melted plastic is springy, so it keeps oozing for a moment after the motor stops, causing bulging corners and blobby seams. Pressure advance (Klipper) or linear advance (Marlin) predicts this and adjusts extrusion ahead of time.

Calibrate with a pressure-advance test pattern and pick the value that gives the sharpest corners without gaps. Typical values are roughly 0.02 to 0.06 for direct-drive extruders and higher for Bowden setups. The value depends on the hotend and extruder, not the filament brand, so you usually tune once per material family.

Speed is ultimately limited by how fast your hotend can melt plastic (volumetric flow, measured in cubic mm per second) and how fast part cooling can freeze it. A high-flow hotend and a strong part-cooling fan are what actually enable clean fast prints, not just a higher speed number in the slicer.

Practical advice: keep outer walls slower than infill for surface quality, raise acceleration before raising raw speed, and calibrate maximum volumetric flow so the slicer automatically caps speed when a layer needs more plastic than the hotend can supply. A 600 mm/s travel move is easy; a 600 mm/s solid infill move may exceed your hotend's melt rate and cause under-extrusion.