I couldnt assemble the original design by 3Deddy without breaking it, so I modified it a little to mount with 4x m3 screws or bolts. You should also be able to use some 3mm filament if you want.
Compared to the original, I made the springs 1mm thinner as they where too stiff, but the little clasp/lid that holds everything closed is still quite firm, maybe a little too firm. Use sandpaper if necessary.
I didnt have too much problems removing the support from the springs, so i printed the backplate horizontally, but YMMV. Printing it vertically will avoid the problem, but take a lot longer.
I used it for my simpit: