I needed a replacement cap for our large storage tanks, and at the same time I wanted a cap that let me attach a garden hose to it. There are two models here, with and without the garden hose outlet.

Updates

• 2022-12-28: Added the Fusion 360 file for editing, and a nicer rendering.

Description

These caps are 63mm wide, and uses what I figure is called a “buttress thread”. It was custom designed thread I had to do in Fusion 360, but it seems to work well. If anyone prints this, and/or has problems or need changes, I'd love to hear some feedback.

Printing

This does require supports, but only from the plate. I intentionally made is such that the “lip” hangs outside of the threads, and therefore easily supports straight from the plate.

I printed mine in PETG, for “food safety”, but I imagine it's fine with PLA as well.