IMALlama

This is true, but also not a huge deal for this design. Store it upright and water isn’t contacting the print. While in use there’s not much prolonged contact, or even contact area, between the water and the print.

These weren’t absolutely leak free, but they didn’t leak any more than the injection molded pices for 2L bottles.

It workes pretty well. Most of the century generators have an oreface that restricts flow, so I incorporate that concept into this design.

The only downside is fluid capacity.

For this particular project, finding a model that already had the threads in it.

More broadly, threads usually follow one of a handful of standards. It’s just a matter of figuring out which standard is being used and then finding the size. I haven’t found a great way of approaching that for bigger threads, beyond measure with a pair of calipers, but if you’re working on nuts and bolts a metal fixture with various threads is the way to go IMO.

Sorry to burst your bubble but these have been a thing since at least the 90s

Oh, I know. I was a child in this era and wanted something similar for my kids.

I just wanted something that could attach to a more sturdy bottle as 2L soda bottles are… pretty flimsy when a kid is shaking them around to get a vortex to start.

I loled. It’s a tornado adapter for a pair of Gatorade bottles. These were pretty popular when I was the age my kids are now, granted they were for 2L soda bottles.