Pilot's Universal Bottle Urinal

I'm a private pilot, and when you've got to go at 5000 feet there aren't a lot of options. But I've usually got some small water bottles handy (the 500ml kind they sell at Wal-Mart, Publix, etc). But they're small and trying to use one of those generally ends up with messy results. So I came up with this.

It's a urinal with a captive plug. It prints as one piece so that the stopper is captured within the assembly (note I've added triangular breakable supports to make sure the center piece stays centered while printing).

Because it's captured, I can't lose it and go fumbling for it in the plane. The entire assembly is still small enough to keep in my seat back pocket or flight bag (bagged, of course).

The bottle threads are *almost* universal and taper to fit multiple bottle types. Each 500ml bottle seems to have it's own spec, so I tested it with bottles from Wal-Mart, Sam's club and Publix (all different threads). The thread itself is posted at https://www.thingiverse.com/thi