Klipper Input Shaper: Online Vibration Graph & Shaper Picker

How to capture resonance data in Klipper

The standard way is to record the response with an accelerometer. Some printers (e.g. the FlashForge Adventurer 5M) have one built in and calibrate automatically.

1. Mount an accelerometer. Attach an accelerometer (ADXL345, MPU-9250 or LIS2DW) to the toolhead. On a bedslinger, measure the Y axis by moving the sensor to the bed.
2. Check the sensor. Run ACCELEROMETER_QUERY and MEASURE_AXES_NOISE — noise is normally around 1 to 100.
3. Run the resonance test. Run TEST_RESONANCES AXIS=X, then AXIS=Y. Klipper writes /tmp/resonances_*.csv.
4. Download the CSV. Grab the files from the printer via the Mainsail or Fluidd file manager, or over scp.
5. Plot the graph. Upload the CSV into the tool above to get the graph, recommended shaper type and frequency.
6. Apply the result. Add an [input_shaper] section (shaper_type and shaper_freq) to printer.cfg, set max_accel manually (the lower of X and Y) and restart Klipper.

How to read the graph

The X axis is frequency in hertz, the Y axis is the power spectral density of vibration. Peaks are resonances; the shaper's job is to damp them with as little smoothing as possible.

• frequency — the frequency the shaper is tuned to (near the resonance peak).
• vibrations % — residual vibration after the shaper; lower is better (0% is ideal).
• smoothing — a relative estimate of part smoothing; higher means it rounds off sharp features more.
• suggested max_accel — the acceleration above which smoothing becomes excessive.
• recommended shaper — the best balance of type and frequency.

Shaper types

• zv — Least smoothing, but least tolerant to frequency error. For stiff printers and very low frequencies.
• mzv — Best balance of smoothing and robustness. Recommended for most printers.
• ei — More robust, smooths more. Good for bedslingers with changing bed mass.
• 2hump_ei — For multiple resonances and delta printers.
• 3hump_ei — Maximum robustness and smoothing; for several spread-out resonances.

The damping_ratio defaults to 0.1 — a good all-round value for most printers, rarely needs changing.

How to apply the result

Copy the recommended values into the [input_shaper] section of printer.cfg, set max_accel in the [printer] section manually (with margin, no higher than recommended) and RESTART. Input shaping itself doesn't slow printing — print time is governed by max_accel.

FAQ