Silicone cartridge nozzle/cap

Standard silicone cartridge nozzles are too wasteful for my taste - you have to push out a great volume of material to fill them and get it going out of the nozzle. Also, there's never one around when you need it, because they're typically single-use. That's not an issue for professionals as they use the cartridges up right away, but us home-gamers have long periods between uses and usually have those things dry up on us before we can use them up.

Therefore, this nozzle is short and has low volume, so you don't have to push much more material out than you need. It uses a small amount of material to print by being a nozzle-only, separate from the hopefully reusable tightening nut, so if you have to throw it away, it's not such a waste. And since the tightening nut is separate, it is modular and can be used with another insert to make a cap. You can also design your own nozzle if you need something special (use the drawing provided for dimensions of attachment).

I recommend printing the plug end meant to keep the cartridge closed with a 100% infill. The plastics used in 3D printing are not impermeable to moisture and solvents (unlike the HDPE or high-density polyethylene commonly used for these applications). A 100% infill will put a lot more plastic between the outer air and the material you want to protect from it.

My own model, but inspired by https://www.printables.com/model/1101273-cap-for-silicon-cartridge by @StefanR_69947 (I also copied his thread dimensions). I was unhappy that the “business end”, the top surface, was too thin and broke off when I tried to tighten it. So I wanted to make it a bit thicker, and ended up designing another one from the scratch.