Hidden wrist blade addon

I took the OTF fidget knife by uhltimate and the handle cover by JDinKC and built a single action wrist blade attachment onto it, so that you can strap it to your arm and with a piece of string connect it to a ring and when you rotate your hand back it triggers the blade to pop out, repeating the action doesn't make the blade go back in you have to flip the switch to make the blade retract, I always wanted one of the hidden wrist blades but all the one I found are full of moving parts. I wanted something simple and after finding the OTF fidget knife I became a big fan of that, then figured if there was just a way to convert that into something on my wrist I would get something close to what I wanted. I went with 100% infill and just look at uhltimate and JDinKC posts to see how to assemble.