2L Bottle to 1/2" PVC Pipe Coupler

thingiverse

This is a remake of @joshburker 's adapter, with pipe side dimensions adjusted to 1/2" pipe nominal size. This modification enables the use of the coupler without wrapping tape around the pipe. A lip was added for the pipe to rest against, similar to a commercial coupler design. The plan is to utilize this part as a reservoir in a homemade squirt gun; we'll observe how well it retains fluid and pressure. Update: a gasket needs to be attached inside the adapter where the 2L bottle screws in; I found that an O-ring size 211 (13/16 ID x 17/16 OD x 1/8" wall) fits perfectly, but that's just something I had on hand. A piece of closed cell foam would probably work just fine too. The challenge is that the 3D-printed surface is not very flat, so you need something to compensate for the gap between the part and the bottle. If enough adhesive is used (use PVC to ABS if you're printing with that; not sure about PLA), it holds more pressure than my lungs can provide! Update: I've tested this up to 100 PSI and it performs well, with the outside surface coated in cement, slipped into an air pump (also with cement). Your results may vary; wear safety goggles and test your first inflation from a safe distance!