It should be possible to 3D printing of enzyme models... but how?

It sends me slightly square-eyed staring at my PC trying to get an idea of the steric requirements for molecules to pass down portals into the active sites of nitrile hydratase enzymes. As a big fan of actual physical models of chemical structures, it would be nice to be able to produce something you could hold in your hand which would complement the computer based view. In my situation this should be relatively simple... there are some nice structures available as PDB files, and just across the courtyard from me there is an engineering lab which specializes in rapid prototyping using the more than slightly magical Z-Corp 3D printer. But how on earth do you convert a PDB file format to a PLY or VRML file that the printer reads? Perhaps naively I thought there would be a site somewhere which you can plug in your PDB file and it spits out something the printer will read. Use of Google to research this is like a step back in time leading to an infinite loop of pages from the turn of the millenium where the crucial link is no longer live, or another link to the Milwaukee School of Engineering or the Scripps Institute who will print a structure for a nice price. Oh well.