Print the parts as shown. The body is printed at a 45 degree angle. The gcode and the picture use a 10mm support enforcer, but a brim is sometimes all you need. I used ABS as the holster sees a lot of UV.
Print the other parts as shown. The two-piece clip screws on the back of the HX870 in place of their belt clip. The two pieces just slide together. You may have to do a little filing to make it work. :-(.
Use a piece of 1.75mm filament as a rivet to retain the slider. The two isometric views show the slider in the open and closed position.
You also need two pieces of Velcro One-wrap ¾"x5" (19mm x 125mm).
I've include .stp (.step) files if you want to modify the project.
The author marked this model as their own original creation.