Lego bricks are easy to replicate on current-generation 3d printers. It's nothing to do with the manufacturing process, it's just that making the molds a bit lo

Lego bricks are easy to replicate on current-generation 3d printers. It's nothing to do with the manufacturing process, it's just that making the molds a bit looser makes them much easier to separate, and cheaper. They also tend to round the peg size up to 5mm, when actual legos are around 4.9. This http://www.thingiverse.com/thing:1005 http://www.thingiverse.com/thing:1005 is a lego-compatible part designed from scratch that describes the issue. Using that, it's easy to make custom parts that attach to legos. Here's one that I designed and someone else printed: http://www.thingiverse.com/derivative:5042 http://www.thingiverse.com/derivative:5042