CaliCross

Every time somebody calibrates motor steps with a 20mm cube a 3D Benchy sinks!

I made this object to reliably check the calibration of your steps, general inner and outer widths and fittings for square and round holes.

It is to big for continuous printing but this is required to have a reliable and "real world" source for measurements. It is not meant as stresstest. if this does not print well, you most certainly will run into problems with real objects!

• The main cross structure is 200 mm x 200 mm with 40 mm wide legs.
• The wide holes are 80 mm long x 10 mm wide.
• The distance of the inner hole to the outer side of an arm is 15 mm ((40-10)/2).
• The distance between the wide hole and the outer perimeter of an arm is 95 mm (100-10/2).
• The center hole diameter is 20 mm and should be perfectly round.
• The round and square holes are 2, 3, 4, 5, 6, 7, 8 mm wide.
• The heights of the cylinder and cubes are matching their width.
• The height of the whole cross is 1,6 mm.

The axis are labeled Y0 Y200 X0 X200 and meant to identify the orientation after the print finished.

The order of different elements is chosen such that you can measure it easily with a calliper.

The additional holes in the center are just meant for cutting the object into four pieces, because you can.

I hope it will help to check and helps to calculate your calibration for X and Y axis separately. Especially showing the difference in step (hardware) and extrusion related (flow / width) calibration. If your differences between different sized objects of one axis are not proportional to the length of the measured vertices, you can be pretty sure that it is not steps related. It also lets you estimate the sizes you need for a quick and dirty scale to fit.

To learn how to really calibrate your printer I suggest reading:

• http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide
• http://www.thingiverse.com/thing:52946