Large calibration square

thingiverse

Here's a 100 x 100 x 1mm hollow cube for calibrating your X and Y steps/mm and squaring the Y-axis. To use it, print and measure it, then input the dimensions into http://calculator.josefprusa.cz/ to determine your correct X and Y steps/mm. Also, utilize a try square to assess the squareness of your Y-axis.