Over on Hackaday.io, [bms.had] is showing his technique for 3D printing molds that he uses to cast (lead-free) pewter objects. The process looks simple enough, and if you have a 3D printer, you only need some lead-free pewter, a cheap toaster oven, and PLA filament. He’s made two videos (below) that do an excellent job of showing the steps required.
Even though the pewter is hot enough to melt the PLA, it doesn’t appear to be a major problem if you quench the piece fast enough. According to [bms.had], a slower quench will melt some PLA although that creates a smoother surface. You can see the 0.31 mm layer lines in the cast, though, although you can use any layer height you like to control that. Creating the mold is simple (the videos use Tinkercad, although anything suitable for creating 3D models would work). You essentially attach a funnel to your part and make the entire part a hole inside an enveloping shape.
Instructions on Thingiverse can be spotty, but [0_o] did an excellent job of laying out what you need to buy and how to assemble it. One of the most interesting parts of the build is the blow sensor. [0_o] tore apart a $5 electronic cigarette and used the sensor within. The mouthpiece is moved like a joystick to actuate the cursor, and the user blows into it for the mouse clicks. Perhaps not a true sip-and-puff system but it made us wonder what other uses you might find for these sensors.
