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Have you used polycaprolactone/PCL aka "InstaMorph" for hobby/projects? It's a very tough plastic that can be melted by putting it in hot water, then formed by hand. I think something like a linkage made out of this material could be a fantastic intentional failure point for certain mechanical systems, as long as the temperature requirement is not much higher than human conditions. Also, if you have a hot air blower, you can repair it in-situ.

I'm honestly not sure why we don't see more of this plastic used for consumer stuff. Something that you can melt down and fix stuff or make little ornaments sounds like a great marketing gimmick. It's also generally a pretty bio-safe plastic.

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In industry, it's because it's so low-temperature. The benefits of using it aren't outweighed by the potential failure risks in it in pieces not designed to be repaired.

Also, just kinda--it's not well known! You can't even find it as a 3D printer filament without a lot of effort, even though those "3D pens" often use it, because the output is so unimpressive to most people. That's not that it is unimpressive, it's because they don't know much about it, much like how people act like there's a "leveling up" by switching from PLA to PETG to ABS.

While from a materials standpoint, its more of a "what fits the needs", from a printing point of view it's definitely a level up going from PLA to PETG / ABS. Both in terms of skill (PETG can be annoying to dial in) and machine reqs (Hot End, ventilation, etc)

ABS is a level up because it curls like mad off the print bed because of internal stresses, and this will cause prints to fail if you do not have a heated chamber, which is a bit of a challenge to set up over Ender 3 like printers. PETG meanwhile likes to be dehumidified under heat first to avoid excessive stringing, which requires a separate doodad, and it likes all metal hotends that do not include the usual internal PTFE tube, which off-gasses nasty stuff if heated above roughly 250°C. PLA has none of these problems. "Level up" is about printability, not material characteristics of the end product.

> "Level up" is about printability, not material characteristics of the end product.

You think that. The people in forums who go "I never print in PLA" despite it having advantageous material properties for some use cases (it's very stiff, for example! sure, it snaps hard, but it's strong until then) do not.

Printability and usefulness aren't on the same axis, but when it comes to FDM materials, a lot of people do.

If you need heat resistance and can give up reforming and strength sugru is a moldable silicone that I’ve used for a quite a number of repairs. A knife handle I repaired in 2014 is still going strong.

(InstaMorph is new to me - but will certainly get used in the future)

Can it be injection molded? If not, I would assume it would be much much more expensive to mass-produce than an ordinary injection molded part.

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