#Interference check

Shows where parts run into each other — that is, occupy the same volume.

It is switched on by a checkbox; the check runs on the assembly in 3D and computes the volume of the common part rather than “do the bounding boxes touch”.

#What counts as interference

Not every intersection is a mistake. A threaded joint, an interference fit and a press fit look like intersections in the model and indeed are. What matters is the amount: hundredths of a millimetre are intent, a five-millimetre overlap is an assembly error.

#When to check

Before release and after every large change. Especially after editing joints: a part that moved a couple of millimetres is invisible to the eye, but the volume of the common part gives it away.