Finally finished my bear trap ring after months of fiddling with it

I went thru something similar last year with a hinged locket I cast in silver. Getting the pin to sit snug without binding was the part that nearly broke me. I ended up reaming the hole a hair at a time and testing with the pin waxed in place before committing, because every attempt to drill it finished just chewed up the seat. Lost count of how many castings went in the scrap pot.

Your comment about adjusting tension by feel really hit home. I did the same with my catch mechanism, just nudging the little leaf spring a little at a time until it clicked shut but still opened with a thumb push. There's no substitute for hands on trial, no chart or formula ever matched what my fingers told me. One thing I learned the hard way, weight on a ring feels diffrent than weight on a pendant. Mine sat on a chain so heft was fine, but a heavy ring spins on the finger and the weight pulls it around to the palm side. You might want to wear yours for a full day of normal stuff before you commit to the bracelet version, just to see how the balance behaves in motion. The half open pendant sketch sounds like the smartest of the bunch honestly, since the chain takes the load off the hinge entirely.

I'd have gone about this whole thing a bit differently. When I did a hinged cuff a couple of years back I learned fast that casting the pivot as part of the jaw is asking for headaches. What saved me was cutting the hinge area out of the wax and casting around a cheap steel wire as a stand-in, then swapping it for a proper pin after. Meant zero recasting just to fix a fit problem, wich was my personal weak spot back then.

The tension part caught my attention too. For mine I gave up on internal springs entirely and went with a tiny catch lip filed by eye, sort of like a purse clasp. Not as slick as your torsion setup, but it meant I coud work the thing one-handed without ever worrying about it biting me, and it never loosened up over time the way a spring can. One thing from wearing mine, though. That heft you're calling charm might get old after a full day on the hand. My cuff bugged me enough after a week that I hollowed the back out with a burr and it still read solid to everyone who saw it. Worth thinking about before you scale up to a bracelet, because at that size the metal cost and the wrist fatigue both pile up quicker than you'd guess.

The wear around the hinge pivot is always the silent killer. You get a perfect cast and then a month later the pin is grinding beacuse the gold polished itself into a slick mess. I learned that quick lesson on a hinged cuff project I tried last year. Even with that 14k gold, the friction at the pivot hole was eating the material too fast. My solution was to add a tiny micro-ball bearing into the pivot seat when I got the fit right. That eliminated the friction entirely and kept the moving parts smooth for years.