calibration waffle

this is a waffle to calibrate your 3d printers filament expansion/ shrinkage, working on a remaster that bends less

while i am working on a v2 it would be smart to increase z-size to 3 or 4mm
v1.4 is great to use as a coaster or ninja star

Global model parameters:
every line is 4mm
every empty cube between the lines on the model is 12 mm
the height is 2 mm
adjacent lines should be 20mm from the external edge of one to another

v1.4 parameters:
externally corner to corner (xy/the big lines on the end of the waffle) is 71.88-71.99mm