I'm wondering about the legal side of this. Is it OK from LEGO side to have stuff like this and other similar tools? And what if when you start printing stuff like that?
I believe the tolerances on Lego for it to be "just right" are fairly narrow, and most 3D printers aren't precise enough (but I could be mistaken). It is likely that Lego has patents on parts of their brick design, so you could be in a fairly bad legal minefield if Lego decides to sue you. Also I'm not sure that describing your project as "a tool for designing Lego" is a good idea.
Yup, the Lego tolerances are ridiculously tight, even for injection molding. 3D printing will generally give you results far worse than even the sloppiest injection molding process.
> It is likely that Lego has patents on parts of their brick design, so you could be in a fairly bad legal minefield if Lego decides to sue you. Also I'm not sure that describing your project as "a tool for designing Lego" is a good idea.
Lego's patents expired in 1989, that's why we now have stuff like MegaBloks. Lego did try to trademark their studded bricks, but that was shut down by the ECJ and others.