I was a bit surprised this item was hardly to find on Thingiverse, found one but still had is flaws and it didn't fit well.
Everyone knows the problem after you use just used a part of your, silicone, acrylic, adhesive or any other product, that after you store it, even for a short time, the product can't be used anymore. The caps provide with some brands are nice but they not work because the air is still getting in.
So I designed a screw cap that holds an O-Ring to seal the cartridge 100% air tight.
Size of the O-Ring is 25.0 outside D - 18.6 inside D. and a thickness of 3.2 mm
Please also press LIKE when you download or collect, thanks.
Also made a watertight box for electric cables that fits, https://www.thingiverse.com/thing:3398756
And made some additional Nozzles