Heron's fountain

thingiverse

http://en.wikipedia.org/wiki/Heron%27s_fountain a gravity powered fountain based on air pressure. You could probably use it as a brainteaser for a high school physics class in the beginning of the school year. I might start a series of water pressure/air pressure demonstrations in the same form factor, then make racks for storing them, etc. Instructions This print, I think is kinda tough. There is a 6CM bridge at the top. However, all the bridges, even the internal pipes, go in the same direction. Feel free to use that skeinforge option to go over bridges perpendicular. All watertight parts (all of them) are at least 5 MM thick. Now, onto actually using it. First, it prints sideways. So, the side with the 2 holes goes on top. Now that you flipped it so that side is on top, pour a liquid down the hole that isn't at a corner, at about 1 CM below the top of the hole, it should start filling slower (it spills down into the lower chamber). Then pour water into the hole in the corner until water comes out of the first hole. TLDR: flip so side with holes is on top, very quickly pour water into hole not at a corner until it overflows, then slowly pour water into hole at a corner until water comes out of the first hole.