Coupler for Gopro Hero 3 to Brunton Echo monocular = airsoft scope-cam

thingiverse

I am trying to devise and build a "scope-cam" for airsoft use... a camera that mounts to the airsoft gun and mimics the view through a scope. Since I had a Gopro Hero 3 handy, I thought I'd try to couple it with a Brunton Echo 7x pocket monocular that I also had on hand. This is a simple coupler to connect the two together, though it requires unscrewing the eyepiece lens from the Brunton Echo first. I apologize for not having more pictures of the result, but I managed to break my Brunton echo on an early prototype that was a little too tight a fit. The uploaded design has been made a little looser, but I haven't been able to try it yet. If you give it a go, let me know how it works. Instructions I think I made this with 25% infill, but it doesn't much matter, I suspect, as long as it's not too small a value. The picture through this thing will be much smaller than full-screen and will be a circle in the center. No crosshairs, of course, since the Brunton doesn't have that. The coupler is made to fit on the Hero 3 lens directly (without the waterproof case, of course). The Brunton end goes on the Brunton scope after unscrewing and removing the eyepiece lens barrel thingie. Hopefully it now fits tight enough to hold, but not so tight that it can't be taken off.