How hard could it be to make a collapsible silicone container? Turns out, it’s really, really hard — collapsible containers have rigid guidelines. Just ask [Eric Strebel], who failed dozens of times before finally getting it right (video, embedded below).
[Eric] started with an SLA-printed two-part mold and a silicone formulation with a Shore durometer of A 40 — this is the measure of hardness for silicone, polymers, and elastomers in the sense that the piece will resist indentation. The first twenty-four attempts all came out looking great, but not a single one of them would collapse and stay collapsed.
Eventually, [Eric] went back to the drawing board and played with the angles of the flex points, the thickness of the living hinges, and the wall thicknesses, which have to be strong enough to stay collapsed.
For attempt #25, [Eric] took the part out of the mold about three hours in and tried curing it in the collapsed state. Persistence paid off, and the part finally collapses and stays that way. Get yourself some popcorn and check out the fail-fest after the break. You know what we always say — fail fast, fail often.
[Eric] has made many molds both from silicone and for silicone. Some of them are really big!
Continue reading “How To Make A Collapsible Container Without Breaking Down”
Between manufacturing technologies like 3D-printing, CNC routers, lost-whatever metal casting, and laser and plasma cutters, professional quality parts are making their way into even the most modest of DIY projects. But stamping has largely eluded the home-gamer, what with the need for an enormous hydraulic press and massive machined dies. There’s more than one way to stamp parts, though, and the budget-conscious shop might want to check out this low-end hydroforming method for turning sheet metal into quality parts.
If hydroforming sounds familiar, it might be because we covered [Colin Furze]’s attempt, which used a cheap pressure washer to inflate sheet metal bubbles with high-pressure water. The video below shows a hydroformer that [Rainbow Aviation] uses (with considerably less screaming) to make stamped aluminum parts for home-brew aircraft. The kicker with this build is that there is no fluid — at least not until the 40,000-pound hydraulic press semi-liquifies the thick neoprene rubber pad placed over the sheet metal blank and die. The pressure squeezes the metal into and around the die, forming some pretty complex shapes in a single operation. We especially like the pro-tip of using Corian solid-surface countertop material offcuts to make the dies, since they’re available for a pittance from cabinet fabricators.
It’s always a treat to see hacks from the home-brew aviation world. They always seem to have plenty of tricks and tips to share, like this pressure-formed light cowling we saw a while back.
Continue reading “Low-Budget Hydroformer Puts The Squeeze On Sheet Metal Parts”