Tube: make a gizmo with pink ball one side, blue the other. Downward pointing water rod with a weight at the bottom with downward angles rods to put pressure on crawly balls. Add a frame top and bottom to stop balls going mad and they will crawl up.
Down under: add multi link chain to ball, have it roll down ramp (build ramp) with something to anchor chain end and it swings in. Use pink ball top and blue botton with rod sandwiched betewen to shoot anchor/hook device to the left.
Haven't had a shower for two days. Kids forgot what I look like.