Input Shaping Frequency Calculator | PrintCalcLab

Calculate optimal input shaper settings based on resonance frequency.

Ringing — those ghostly ripples echoing sharp corners across a print's surface — comes from the frame and toolhead resonating after rapid direction changes. Input shaping cancels it by reshaping motion commands around the machine's resonant frequency, but each shaper type imposes its own acceleration ceiling. Given your measured resonance frequency and printer kinematics, this calculator compares the ZV, MZV, and EI shapers and recommends the one that conventionally suits your machine type.

How It Works

Each shaper's recommended maximum acceleration is the resonance frequency squared times a shaper constant: 0.39 for ZV, 0.50 for MZV, and 0.60 for EI. At the default 45 Hz, that yields roughly 790 mm/s² for ZV, about 1,012 mm/s² for MZV, and 1,215 mm/s² for EI. The recommendation follows common practice per kinematics: MZV for CoreXY machines, ZV for deltas, and EI for Cartesian bed-slingers, whose less rigid frames and broader resonance peaks benefit from the more aggressive smoothing.

FAQ

How do I find my resonance frequency?

Either run an accelerometer-based measurement — Klipper's ADXL345 resonance test reports the dominant frequency directly — or print a ringing test tower and compute the frequency from the ripple spacing and print speed. Measure each axis separately, since X and Y usually resonate differently.

Why does EI allow higher acceleration than ZV?

The constants reflect each shaper's character: EI's 0.60 factor versus ZV's 0.39 means the same 45 Hz machine is allowed roughly 1,215 mm/s² with EI but only about 790 mm/s² with ZV. The trade-off is that the more aggressive shapers also smooth away more fine surface detail.

Which shaper should a CoreXY printer use?

This calculator recommends MZV for CoreXY, matching common Klipper guidance for rigid, well-built frames: its 0.50 acceleration factor sits between ZV and EI, balancing vibration cancellation against detail smoothing.

What happens if my frequency measurement is off?

Shapers cancel vibration in a band around the configured frequency, and the acceleration limit scales with frequency squared — a 10% frequency error shifts the computed ceiling by about 21%. Re-measure after any change to belt tension or toolhead mass, since both move the resonance.