I'd be worried about the sudden shock to your finger tendon pulleys in case of a failure. Crimp rehab sucks.
... but I do want to see how this project turns out. Maybe I need to research the tensile strengths needed here.
I might do a test with weights to see what it can hold. But im really confident this is beefy enough.
Personally I'd skip the test, I don't think it's going to give you much valuable information.
The problem is with how PLA and printed parts fatigue over time. So it will hold you the first 10 hours* and then suddenly fail.
All materials have an amount of stress that will cause them to deform, and an amount of stress that will cause them to break. Every time you bring the material near its breaking load limit it deforms in some way, but not always visibly. Sometimes the deformation is on the microscopic level, or internal. So it works until it suddenly doesn't. These points are closer or farther apart depending on the material. Steel will usually deform much earlier than it will break. Aluminum, on the other hand, will give you less warning.
The other thing is that weights are unlike a live human load. Human beings move around and generate force much higher than their bodyweight. Generating 2x your bodyweight is trivial. I saw someone hit 6x on an aerial apparatus, and the rigger said he's seen 10x on a long drop from the ceiling where the person catches themselves at the bottom. But I have a feeling you're not going to be be dropping onto this thing from 20 feet up.
Looking at your design, if I had to guess where it was going to fail I'd put my money on the screws pulling through the holes. I'm not an expert tho.
It looks like you've got a bunch of good info on this thread on the possible risks of the part failing (idk what crimp rehab is but it sounds unpleasant) and you can decide for yourself whether that's something you're comfortable with.
*I'm making up random numbers here
Thanks for your insight. But you can look up how hangboard training is done. Its basically just seconds of hanging on your fingers with regular pauses in betreen. There aint much movement involved. But ill definitely try this forst set of grips out and do some good torture test before i print the other ones. I aint throwing 500g of filament away because some on the internet are concerned. (Criticism and the constructive feedback i got is alwaxs very appreciated. Thats why i post here on reddit)
Edot: i think a lot of the people here overestimate my finger strenght ^
Oh yeah, to be clear: I think it's fine. But I always like to give people the info to make informed judgements. Everyone has a different level of risk tolerance. For instance, I like to climb a ladder up to a 20 foot high platform, grab onto a trapeze bar, and then backflip into the net below without any safety lines. But I won't hang upside down on a doorway pull up bar.