Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4835678.
Update 07 May 21 Tweaked liners again to a thickness of .6 mm. Tweaked caps: different ridges and slightly thicker outer wall.
Update 05-May-21
Renamed files. Tweaked liners to be .5 mm shorter in diameter for a better fit.
38-400 caps for home brewing. Have you every grabbed some cider and kept the jug to ferment in? Well, so have I and now when I run out of bungs, I can use these caps to either seal or ferment in...when I lose the metal cap :)
Designed to have room for a lid seal - TPU .stl included for a plain cap and for one with a .25 inch hole which is perfect for a grommet.
I verified that the cap with TPU seal does seem to be air-tight and allows airlock to bubble with my current set up, but will continue to test.
Will also accept bone-fide 38 mm lid seals