In some countries like where I live (Turkey), we are troubled with the hand pumps to deliver water out from a container. Some hand pumps are cumbersome and small kids have a problem with providing the required power. So I thought about using a foot pump instead of a hand pump.
Step 1: Putting All the Required Pieces Together
1- You would need to get a high-pressure foot pump. I bought mine from a camping store at around 6 EURs. Normally it is used to inflate an air mattress. Since no harms will be done to it, still you may detach it from the setup and use it as it is.
2- I have used an old broken hand pump and took all the upper components away. There is a pipe that goes into the water container, but its diameter was different than the pump's hose. So you would find a 3D model of an adapter (pump-adapter.stl) I designed to keep the pump's hose and the bottle together. Slight modifications might be required since different hand pump manufacturers have various standards.
3- topcase.stl is a 3D model to close the missing top of the hand pump
4- spout.stl is just an extra tool in case you might need it.
Step 2: Assembling the Pieces
1- Mount the 3D printed adapter to the top opening of the hand pump.
2- Use the 3D printed top case to cover the mechanism
3- Put the air pump's hose and the adapter together tightly.
Step 3: You're Done! Use Your Foor
If you'd be able to prevent any air leakage, you are good to go.
Enjoy your healthy drink!