Blowgun Mouthpiece/Cup

I noticed that nobody had a blowgun mouthpiece designed on here yet so I decided to make it my first contribution. Blowgun mouthpieces I consider an important part to making any blowgun.

I modeled this with FreeCad, because it's free, runs on Linux, Mac's, and Windows. Theoretically I could also model this with freescad so that It's customizable, but I'll tackle that if there's demand.

I've designed this to fit on the end of 1/2" Schedule 80 pvc pipe, that most home-made blowguns are