Well, the problem is that the kind of brace you’d want has to be shaped by hand right now.
3d printing will likely get there eventually, but turning out a chest/back brace that’s not only effective but wearable is as much an art as anything else.
I’m not sure where someone without training would get started. Orthotists and prosthetists are specialists; orthotics is a master’s program, and that’s the kind of endeavor your desired brace is.
It’s doable for sure; though whether it’s practical to recreate the decades of research and experimentation that led to where orthotics is today is a different issue.
Iirc, you’d start with thermoplastics, I can’t recall the ones that are used. But they’re shaped by mold, taken from the patient directly, then adjusted during fittings so that there’s no/less issues with long term use. And you can’t just skip the kind of shaping needed. Afaik, nobody is printing orthotics yet. Casts, yes, though that’s fairly new; but those are short term use, so don’t require the same kind of fitting.
I’ve seen, and been present during fittings for, braces for scoliosis, which is going to be similar to the kind of orthotic you’d need.
If you decide to go the home brew route, you’d want to start with a plaster cast of your torso. Best way to go, so you can have a solid form to shape whatever material you go with.
TPU was a common material back when I was still a caregiver, though that has been over a decade ago now, so it may have been supplanted by other thermoplastics.
Carbon fiber was starting to be used back then, but it tends to be too rigid for applications like a torso piece. Maybe with enough foam in between you and the rigid parts, but at that point, why not just go with something less expensive, and more flexible? Iirc, CF was being used for things like leg and ankle orthotics where they’d be bearing weight and need the extra rigidity.
I know that there was CAD based modelling and fast prototyping being done for orthotics, but it was mainly useful in prosthetics, where they could make reproducible units that would then be customized.
Tbh, I would try finding an orthotist irl to meet with and brainstorm. Even if they can’t/won’t help you make your own gear, they’ll likely still warn you off of really bad ideas.
That’s at least in part because you say you have little interest in medical or anatomical study, and that’s what you need if you want your end device to do the job you want. You just can’t fine tune a torso brace without understanding the musculoskeletal system in that area, and what you’ll need to avoid doing.
Like, the curvature of the spine. It may seem like you could just mold your body and make the brace conform to that. But, if the goal is to give support to part of your body, the brace has to apply pressure to your body applying it at the wrong place, or in the wrong way could make things worse. So if you don’t have the time/interest/willingness to gain the level of understanding of anatomy to achieve that, you’ll be better off consulting with someone that already has that knowledge. It’s kinda like self surgery, there’s only so much you can do blind without causing problems worse than what you’re trying to fix.
No, no, they have big balls. Bouncing to the left and to the right.