Many people have the means now to create little plastic objects thanks to 3D printing. However, injection molding is far less common. Another uncommon tech is plastic recycling, although we do occasionally see people converting waste plastic into filament. [Manuel] wants to solve both of those problems and created an injection molder specifically for recycling.
The machine — Smart Injector — is automated thanks to an Arduino. It’s pretty complex mechanically, so in addition to CAD models there are several PDF guides and a ton of pictures showing how it all goes together.
According to the documentation, the extrusion screw can provide 51 Nm of torque with a 48V supply using a NEMA34 stepper and a 6:1 gearbox. The machine can make an iPhone 8 cover in about 4 minutes and costs about 1000 Euro to build.
Of course, melting and extruding plastic isn’t the big trick. That lies in clamping the mold. That step is done with a threaded rod and a NEMA17 stepper. Then again, the other trick is developing your molds which need to have an ejection mechanism specific to the molded part.
While some people might be put off by the statement that the machine still needs some manual intervention due to unresolved clogging and clamping problems. We’ll bet that will be a challenge to Hackaday readers who will be happy to help resolve those issues.
If you build it, we’d love to hear about it. The project reminded us a lot of another iPhone case maker we saw a few years back, although some of the links there are dead. If you want to practice with something cheaper, try hot glue and some ingenuity.