5 Gallon Bottle Sealing Cap and Collar

thingiverse

The driving force behind this design stemmed from a pressing need to top off several 5-gallon water jugs, thereby preventing dust from accumulating inside and stopping water from spilling during transport. After experimenting with various designs from others that consistently failed to fit correctly, kept breaking, or leaked excessively, I decided to create my own solution. I chose the square cap design to prevent it from rolling under a car when inevitably dropped at a filling station. This feature eliminates the risk of losing the cap and reduces clutter on the ground. The ring washer is an optional component that keeps the collar from coming loose too easily while still allowing for effortless removal of the entire assembly when placing the bottle on a water dispenser. If you wish to replicate this design, note that the threads utilize an ISO Metric profile with a 76 mm diameter cylinder, M76x6 thread, Class 6H, and a right-handed thread. To achieve a watertight seal, I acquired some 1/8 inch food-grade silicone gasket material and adhesive. Using the gasket template and a hobby knife, I carefully cut around the outer edge of the gasket, then secured the center to the center ring of the cap. The outer edge of the gasket is designed to flex as the center part of the cap pushes into the bottle hole.