My brother-in-law is an RC model maker. He needed an 1:15 scale model of a fire monitor and he couldn't find one. So he ask me if I could create one. Jip - I was able to do that ;-)
If you're using metal pipes and a hose connected to a pump that thing is able to pump water. So much fun for him to use the thing and so much fun for me to build it. First thing I've build for RC models.
Update: Set of gears (2:1 and 3:1) added if you want to drive the thing with a motor.
Das Filament PETG
Schwarz - Refill
You can mostly print this without support. Only the part that is connected to the metal tubes (FireMonitor-ExtinguishingTubeMount-ExtinguishingTubeMount_Water.stl) does for sure needs support.