Since I wanted the goggles I made to lay flat on my dragonhead, I added the 3rd set of tabs for straps that goes under my ears as it wraps around the back of my head. I didn't want to use the wider 1.5" straps like I did for the upper tabs as it would be a bit overkill and heavy. I have some .75" straps but they are not quite long enough. I do have plenty of the double sided 1" wide hook and fastener strap that I already used for going over the bridge of my nose.

So I modeled and printed up these bad boys, a pair of strap adapters that nicely swivels to prevent any binds. The prints turned out really nice and took less than 2.5 hours total. The pieces fit together nicely although I had to adjustment to the disks to make it flush while still allow the sides to pivot.

I used FreeCAD to model the parts and let me tell you, it is nothing like the SolidWorks I have at work. Everything took a lot longer to do in FreeCAD and is a pain in the butt. I had to pretty much plan every step in advance and if there is a change, I end up redoing the following steps as FreeCAD goes bonkers. SW can break stuff but no where near this bad. Still, it is free and I did get something done in the end. But the fit and polish is lacking. Not even the save dialog is done well, it doesn't even show the previous filename of the part in the save-as box as a start and I have to type the title of the part from scratch. But I digress, I worked well enough... barely.