Child powered marble lift

This is a u-bend pipe for attaching a 1L pop bottle to a hollow stainless-steel curtain rod. It will function as a child-powered marble lift, for a marble run I'm building for my kid.

This is UNTESTED - I don't have a 3D printer. But I don't think I can make any more improvements without printing it, so I'm going to call it done for now. I'd be especially interested to know if the overhangs are a problem for the makerbot or any of the other FDM machines.

Edit: cleaned out a random trian