Pipe ring seal demo

This is a small demo on how you can create watertight seals with a 3D printer. The cup and pipe can be printed with PLA, the seal ring must be printed in a flexible filament. Make sure you can print a watertight cup first, before printing the pipe. For the seal to work it is very important that your filament is dry. Note that the seal ring is both too wide for the cup and too narrow for the pipe. This ensures that the seal is compressed properly, otherwise it would leak.
To test whether parts are watertight I like to set them on a piece of toilet paper overnight. Even a single drop of water on toilet paper is very easy to spot.