Here is a simple protective tube for anything around the size of a .510 1g cartridge. You can of course use it for other things, and there is about 60mm of length to work with in there. If that doesn't work for you then scale it, or leave me a comment. 

The threads have been optimized to have a bit of give for any printer, but once threaded have a great seal. I would not consider this waterproof, but its perfect for the beach or to keep dust out. 

Thanks for the support!