Extruder linearity correction calibration
Linearity correction is based on Trinamic stepper driver feature that allows defining a custom current-waveform. Default Trinamic waveform is a sine function, but real waveform can be a little bit different and depends on the stepper motor type. Also, motors of the same type can have different waveform. The biggest distortion appears when the wave is crossing the zero point (or around it), so the original sine wave is modified using power function to eliminate this distortion.
Linearity correction calibration procedure
- Download and print the Calibration Gcode
- Find a place with the best surface on the calibration object and calculate the correction factor.
- Focus especially on 45-degree lines visible as a darker reflection
- Most printers will have minimal distortion around the vertical center of the object (value 1.10)
- Adjust Settings/E-correct to the calculated value.