This gizmacci is an element in my 3D Printer Enclosure.
This is an adjustable vent that sit atop the plexiglass enclosure to passively vent hot air and fumes through convection. This is designed to fit in 2 inch hole. I had very good success with a new hole saw at slow speed.
The pin the vent spins around is a section of 3.0 mm ABS filament that has the ends "peened" with a hot element, like a soldering iron. You can clean out the small hole with a 1/8" drill bit which is just a tiny bit bigger than 3.0mm.
You will need some nasty-ass chemistry to bond ABS and Acrylic - I used Devcon Home Plastic Welder, but other comparable products exist.