Patriot Contraptions built a fan holder to prevent fogging in this goggles with 3D printing... "It been a long time since I played with my 3D printer, but its now back in action. The first test project is to build a fan holder for my goggles so the will stop fogging. I got this idea from some paintball and airsoft guys who I talked to about the small fans the had on their masks. The problem was they were at least $20 for the kits and way more for built into google.  Therefore it was time to 3d print my own prototype."