General Calibration for Ender-3
Calibration:
There's a "Getting started" section in the Marlin Configuration.h, might be helpful for calibration:
/**
* Here are some standard links for getting your machine calibrated:
*
* http://reprap.org/wiki/Calibration
* http://calculator.josefprusa.cz
* http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide
* http://www.thingiverse.com/thing:5573
* https://sites.google.com/site/repraplogphase/calibration-of-your-reprap
* http://www.thingiverse.com/thing:298812
*/
Skew:
**
* Bed Skew Compensation
*
* This feature corrects for misalignment in the XYZ axes.
*
* Take the following steps to get the bed skew in the XY plane:
* 1. Print a test square (e.g., https://www.thingiverse.com/thing:2563185)
* 2. For XY_DIAG_AC measure the diagonal A to C
* 3. For XY_DIAG_BD measure the diagonal B to D
* 4. For XY_SIDE_AD measure the edge A to D
*
* Marlin automatically computes skew factors from these measurements.
* Skew factors may also be computed and set manually:
*
* - Compute AB : SQRT(2*AC*AC+2*BD*BD-4*AD*AD)/2
* - XY_SKEW_FACTOR : TAN(PI/2-ACOS((AC*AC-AB*AB-AD*AD)/(2*AB*AD)))
*
* If desired, follow the same procedure for XZ and YZ.
* Use these diagrams for reference:
*
* Y Z Z
* ^ B-------C ^ B-------C ^ B-------C
* | / / | / / | / /
* | / / | / / | / /
* | A-------D | A-------D | A-------D
* +-------------->X +-------------->X +-------------->Y
* XY_SKEW_FACTOR XZ_SKEW_FACTOR YZ_SKEW_FACTOR
*/
//#define SKEW_CORRECTION