Hi all, I've been ordering from shapeways for nearly 10 years now. More recently, I've been ordering parts in steel, bronze and aluminum. The parts are about 25x50x5 mm plates with 30 channels and holes (abt 1.5 mm in diam). The plates are used as heat exchangers at 37C. I post-process parts by fly-cutting on a mill and cleaning up the holes with a drill press: all I need are two flat surfaces and the holes. Out-sourcing CNC-machinning these same pieces is more expensive than 3D printting. When milled, the parts look like 'solid' metal, i.e. no pores etc. I am now thinking if I can print a single-piece steel, brass, or aluminium 'bathtub' mould with posts and pedestrals where the holes and channels would be, and use the mould to cast tin plates. Will this work? Can I even use the cheap tough plastic (melting temp 250C?) to cast tin (melting temp 240C, ok, that's too close) or some other low-melting temperature metal? I understand that the cast pieces will need to be fly-cut, and holes will need to be finished off, but I need to do this with 3D printed Alu and Steel pieces anyway (I am fine with hole marks instead of actual holes). Tin is pretty easy to drill/mill.