Easy 3-axis Skew Calibration Tower with Spreadsheet

This is an easy-to-use 3-plane skew calibration tower. The 60mm diagonals are labeled for easy meaurement, and a spreadsheet is provided to calculate the I (XY), J (XZ), and K (YZ) parameters for Marlin and Klipper.

Turn off skew correction before you print. Use a normal layer height (0.15mm) and no supports. Do not rotate the model in your slicer - it must be printed in the same orientation as supplied in the STL.

Then, open this spreadsheet and make a copy.

Use calipers to measure the six diagonals, conveniently labeled A to F, and type the measurements into the spreadsheet. It will calculate your three skew correction factors. Send them directly to the printer using the supplied M852 command, or add the skew profile to your Klipper config file. If your printer's firmware does not support skew correction, install alternative firmware that does (e.g. if you have the Prusa Mini you can use Llama Mini or Klipper).

If you want to check your calibration is accurate, print the same tower with skew correction enabled. The diagonals should then all have the same length (within measurement error of course).