In the past we mentioned that about 20% of our printed bottleplugs were not completely tight for gas and liquids. Because we could not fix the problem (in short time) with slight modifications in the design files or adjusting the printing parameters, we decided to create a new plug.
It works very well but, it is not completely 3D printed, you will need some brass tube in addition.
To build it, you need two pices of brass tubing with an outer diameter of 6mm (15mm and 67mm long), the 3D printed body and the soft seal which was also used in the other plug design. We strongly recommend to use a pipe cutter to cut the brass tubes. Press the brass tubes into the 3D printed part by using a soft hammer, shop press, vise or something similar.
You will find the new .stl in the misc folder.