I printed this out of PETG for some added strength and added some foam inserts to grab hold of the arrow. I use it on my 4mil and 6.5 mil arrows but it should work with any size. For the pin in the joint, it’s just long enough to reach both sides with a little excess and then I soldered it to the outer part of the hinge so it does not come apart.

Note: it does require some sort of foam insert to grab the arrow properly. I used some dense black foam from floor pads. I have included an insert to be printed separately out of TPU if you choose to go that route, but I can't guarantee how that will grip the arrows because I haven't tested it. I recommend cutting your own foam for it, but the insert is there for those who want to try it.