WATCH FULL TUTORIAL: https://youtu.be/mBQtlUpXhmo
This 3D printed water pump is working with two engines and has a gearbox with a gear ratio of 1:1,5. This water pump is capable of pumping 410l water per hour.
The body is printed with PLA but gears and turbine are made of ABS. I am sure that PLA works also totally fine, but I am a big fan of printing gear whit ABS.