Interlocking Part Tolerances

The assemblies are commonplace, to be functional some points of attention are to be noted.

If a 3D model includes two interlocking parts, it will be necessary to leave a distance of 0.3 mm between parts for easy assembly.

For example, to insert a 10 mm cube into a square hole, the hole's side should measure at least 10.6 mm (+0.3 mm on each side).

Also, it will be necessary to consider the overall dimensional accuracy of the part.
For example, Pam 3D printers offer a ± 0.2 mm dimensional accuracy but the material shrinkage will need to be considered too.