Has anyone made their own custom LEGO bricks? As I've just learned, LEGO bricks are made from ABS plastics.

I wonder if it would be possible to make some simple molds at home, get some ABS pellets, melt them up and make your own custom bricks? Novelty shapes or colours, perhaps?

Has anyone tried this, did it work?
People with 3d printers have made their own LEGO bricks. The plastic used is ABS.

Blog post



Interestingly, 3d printers can be constructed out of LEGO parts - you could have it self replicating!

Of course, you would need a very expensive and high quality printer to make good pieces. Cheaper ones can only make hollow bottoms and the banding from manufacture is highly visible.