Bravo! I needed a wrench for a 1/2 gallon U-keg… I had to resort to asking a body builder for help to release the cap!I love this thread. Very inspirational and reminds me that there are so many uses in our hobby for custom items. Here is a Carb-cap wrench I made. Super-simple, but I was having trouble unscrewing these things by hand.
edit: I have been printing for 4 years, Ender 2 v2, Openscad, Cura.