1.7 KiB
VFA calibration
VFA means vertical fine artifacts: fine vertical banding caused by a stepper motor’s torque ripple. It is different from input shaping. Your printer already has factory VFA values, so recalibrate only after replacing a motor or when visible banding remains after normal tuning.
Before you start
- Make sure no print is running.
- Remove the build plate.
- Make sure the printer is homed and the carriage can move freely.
- Leave the toolchanger empty; Reforge mounts a tool automatically for the measurement.
Run the calibration
Send these commands from the Mainsail Console, one at a time:
STEPPER_RESONANCE_FACTORY_CALIBRATE
SAVE_CONFIG
The first command measures the X and Y motors. The printer will move quickly
and make a noticeable vibration noise while it searches. Wait for it to
finish before sending SAVE_CONFIG.
SAVE_CONFIG is required: the first command applies the correction for the
current session and stages the values, while SAVE_CONFIG writes them to the
configuration for future restarts. It also restarts Klipper.
Afterward
Wait for Klipper to reconnect, then run:
STATUS
The VFA correction is applied by the printer’s motor drivers on subsequent
moves. It is independent of SHAPER_CALIBRATE and does not replace input
shaping.
Example
This comparison shows the same speed sweep with VFA compensation disabled on the left and enabled on the right. Speeds run from 80 to 200 mm/s, right to left. The enabled side has visibly cleaner vertical walls and fewer fine bands.
*VFA disabled (left) versus enabled (right).