x-y step calibration very precise

This method is not affected by extrusion width and be more precise in compare to model where you measure the outer width.
Use sharp tool to scrape lines between holse to make a cross . Measure between cross points.
I use 150mm version because my caliper can measure up to 160mm.

To online calculate steps use 3.2 step in this document:
https://docs.google.com/spreadsheets/d/1AYurIUz6pwcJbzzpIF4UwgEXCtxaEZ0okNuJRrKAkT8/edit?usp=sharing

Or download excel file here: https://www.thingiverse.com/thing:2390274/files

MARLIN users:
read current settings from EPPROM: M501
set new values: M29 X80 Y80 (where 80 is you value)
save setting to EPPROM: M500


3D Sources:
100mm
https://cad.onshape.com/documents/df6a901e0e10cb74a49109e7/w/99246e711677e8b703c7653d/e/e7cae0c95fa1ba356d9b730f

150mm
https://cad.onshape.com/documents/ccba722a04a88daba98dc44e/w/014b2f853c65f451c64206b7/e/9a8ab64de303c77d7a369133

180mm
https://cad.onshape.com/documents/73b8051e22051ec5403de33e/w/dfa9