I muscled the headset buckle on my HTC vive a bit too hard when removing it, and one of the tabs broke. So I measured everything, made a CAD model, and printed this replacement. it works great (yes, I really use it and I'm not worried about the headset coming loose)
IMPORTANT: Use a strong material with some elongation (flex) strength. Mine worked best with Taulman Bridge Nylon. I also tried Taulman Tech-G, but it didn't quite have enough elongation before it would snap. Test it before using it by giving it a reasonable pull / twist, etc. This buckle, like the original, works by flexing and pulling a bit, making the tabs pull tight into the slots.
My best print:
Taulman Bridge Nylon
0.15 layer height
Oriented on the large, flat, back side
45 C bed
Use fine supports set at 45 degrees (I used simplify 3D with supports set 1mm^2 threshold). This will make some small supports under the hooks of the tabs so they come out just right to grip the headset. I also set the speed slower when printing the tabs only.
Due to the nature of printing small tabs with nylon, they weren't perfect and the supports hare harder to remove in nylon. I scored them and filed them off patiently to make a good flat edge under the tab.
Very relieved that I don't have to worry about the headset dropping now.
I didn't try ABS, PLA, or other materials. Just use something that can take some pulling and stress...
Made with Taulman Bridge Nylon. Nice and strong.
0.4mm nozzle, 3 shells, 3 top and 3 bottom layers (fewer will be more flexible, more will be more stiff).
Make sure it fits and is strongly seated
Don't want this expensive thing dropping... Be sure to test for strength before use.
Made in Inventor / Fusion360
Drew it up as a solid model, mostly in Fusion 360. I've included a STEP file in case you want to play with it.