
Clearances
==========

The blocks are NOT exact multiples of the unit-size; they are slightly smaller.
This is to account for innacuracies in printing.
Imagine a BIG back block, say 20x20x1. Now imaging placing a row of brick horizontally.
If the blocks cannot squeeze close enough, then the holes won't match up with the 20x20 base.

There are two clearances `clearance` and `clearanceZ`. The former is for the X and Y dimensions.

