Minkowski mold, die, slider demo

thingiverse

For making molds, simple dies for die casting, or nested/sliding parts, openscad could have your answer, the Minkowski algorithm. Normally, moving all vertices of a part orthagonal to the surface so as to create a constant depth or wall thickness, that takes some expensive software. And while there are some low cost CAD software packages like MOI, they are rare. So it depends on how simple you want to keep things, and how much time you want to spend, because the Minkowski can take time. But suppose you want to nest two parts. The following example shows how to do this, and it works. Two number 5's are supposed to nest. If you make a shell, but shrink the fitting "five"... surprise, it doesn't work, it doesn't fit because of interference. Conversely, scaling the outer shell larger also doesn't work for the same reason, call it complexity interference for lack of a better visualization But if you use the Minkowski to create a constant distance shell, the two parts fit like a glove. Here are two number fives each with a different fit distance on the bottom mating shell. This could just as easily be the mold for a part, or a die casting machine. But..hey, it works, and it's a fun print, much better than the one where I broke off one five inside the other interfering shell "just to convince myself"!! That I broke the number off in front of my wife didn't help my ego, but that's a whole different story!! :).....