This is a simple system for attaching HTC Vive Trackers to your belt for full-body-tracking purposes. May also work for attaching stuff elsewhere, if you have the right straps.

There's another tracker belt loop on Thingiverse, but it didn't make inserting the belt easy, would cut up the belt due to lack of chamfers, and I didn't like the orientation of the tracker. I also have an enormous leather belt (35mm wide!) I was going to use this with, so it wouldn't have worked.

I have included the FreeCAD file so you can make adjustments, if needed. Sketch003 is the one defining the size of the belt holes. Be sure to add some slop to allow the belt to move.

Requires a fitting belt, preferably made of something flexible like Nylon. Also requires a 1/4" x 1/2" bolt. I designed this for a item number 61820 bolt I grabbed from Lowes, so YMMV.