Bag Cap/Clip/Lid - Small, Large, Extra Large

I found bag clips with lid on this site either too flimsy or too complicated and decided to design my own version, which is simple, yet very sturdy and functional.

If you slice it yourself, be sure to use layer heights no thicker than 0.2mm. The quality of threads will degrade with thicker layers.

Unlike standard bag caps (like Copco) which use a 'snap-fit' that can pop off or fail on thick bags, this design uses a ring and a locking nut, which allow you to generate massive clamping force, creating almost a liquid-tight seal on anything from thin foil to thick multilayer coffee or dog/cat food bags. It works like a plumbing compression fitting, but for your snacks.

I include an experimental watertight model/profile, which must be printed in TPU filament. TPU is much better for watertightness than PLA or PETG, but I still had to make some changes to the model and the profile to make it fully waterproof. In my tests it's watertight with thin kitchen plastic bags even without silicon grease. Otherwise, applying grease to the grooves of the stem part helps.

Three sizes:

• Small has an M50x4 thread and is suitable for smaller coffee or grain bags.
• Large has an M80x4 thread and is suitable for cereals bags, dog/cat food etc.
• Extra Large has an M100x4 thread and is suitable for large dog/cat food bags etc.