5L PET fermenter airlock cap

thingiverse

A Bottle Cap Designed to Fit 5L PET Water Bottles with an 11mm Hole for Airlocks. I recently came across designs similar to this one, but they were tailored for smaller mouth bottles and did not work well when scaled up to the larger size. I took inspiration from danceyoga's design and created a new version with an 11mm hole in the center. When printing the hole, it turned out slightly undersized for my needs, but it still worked perfectly with my airlock. I am currently testing this design with a batch of bottles and plan to make improvements as needed. The results so far are promising, and I am confident that with some tweaks, this bottle cap will be even more effective. There are a few areas where the design can be improved: * The hole should be enlarged to accommodate thicker-stemmed airlocks. * The material around the hole is thin and flexible, which can cause it to flex when an airlock is inserted. Strengthening this area may be necessary to prevent damage. * I plan to create a new version of the bottle cap that includes a rubber grommet for a tighter seal. This will provide an additional option for users who prefer a more secure fit.