There are few things more beautiful to me than machined aluminum. So, I was delighted when my friend Brett Shellhammer invited me across the Hub courtyard last week to check out the plastic injection mold he had milled and test driven at TechShop in Detroit. For the uninitiated, injection molding is how the enclosures are created for lots of your plastic consumer goods. You put these two mold halves together like a sandwich and use a big press to force molten plastic through that port in the piece on the left. When you crack the mold open, you have a hard plastic shell the shape of the mold cavity.
“So what?” you might say. Your iPhone case, laptop case, and coffee maker are all made this way. Very familiar, right? Well, the thing is that five years ago this process/skillset/toolset was invisible magic and we only ever had access to the output. The maker movement has facilitated a tectonic shift in that dynamic.
Serial entrepreneur and outwardly a business guy, Brett is also a hardcore maker, fueled by a large desire to GSD (get shit done). So when his latest endeavour, The Quiet Coach, needed a plastic enclosure for part of their product and 3D printing was falling short, Brett flexed his maker-fu. It’s not a trivial workflow. He needed to 3D-model this enclosure in software. Then he took that virtual model and create an optimized toolpath for the CNC mill. He trained on the mill at TechShop, and then actually ran his toolpath against some aluminum stock to carve out the shape. More training, this time on the injection mold press at TechShop, was necessary. Finally, he had a complete toolchain with which to experiment, molding shells from different plastics. More importantly, he is now equipped to apply his learning to future challenges, not only in enclosure fabrication, but in any hurdle that requires modeling, machining, or CNC technology to surmount.
This is a small example of the watershed in manufacturing. It doesn’t supplant offshore manufacturing for large volume production, but rather complements it. Smaller volumes and quick-turn design changes (we used to say “rapid prototyping”) are within the grasp of mere mortal makers.
Click through for a few pics of the output and more machining porn…