This is a simple cap for a gallon jug. I was thinking of using something like this for brewing or some other DIY project. I made one with a hole big enough to fit a 1/4'' or 6 mm tube through.
I tested the one without a hole by filling a gallon up and holding it upside down for a minute. I didn't see any sign of leaking, so it is at least somewhat water/air tight.
I used Dan Kirshner's OpenSCAD threads library with the following.
- Exported to stl
- Imported to another program
- Subtracted from 40 mm cylinder
- Cut in half
- Layered 3 copies of the object at 0 degree, 120 degree, 240 degree rotations
- Added supporting walls and top
- Put a radius at the top