Raiscube Z-axis (X carriage) aligment posts

Added 'want_post' parameter to generate holder separated from alignment posts, and increase height to 130mm to suit my printer's need.

Measure your printer's X carriage height after homing and add about 10mm for clearance. You won't need more than that.
The shorter you print, the more stable the posts stand and the less plastic is wasted.

This is the last in my XYZ calibration setup. After this calibration my Raiscube printer print as accurate and reliable as my Ender 3 if I keep the spee