This is a design to mount an HTC Vive to a Fast helmet with rails. You need to print one clip, one mirrored clip (for the sides) and a hook plate (for the front). The first is to remove the default strap. Keep the two metal rings. You will need two 1x12 inch cable straps (such as this one) and one 6 inch cable ties (such as this one).
You also need a QD plate for Fast if you don't have one. You can either buy it (such as this one) or print it (download the model here).
Use two M5x12 screws with M5 nuts to mount the hook plate to the QD plate.
- 100% infill for clips might be a good idea.
- Add help disk for clips. Because the design contains sharp angles.
- Print the hook plate along the long edge (the hook for cable strap should be parallel to the printing plate) for better strength.
The design files can be found in OnShape.