For the architecture section group project, a bartending ring was developed which would automatically pour drinks at the press of a button. I was on the pouring team developing an easy way to pour the beverages into the cup. I stared brainstorming with a 4 bar linkage system to pour a shot glass that could be dipped into the drink repository.
Next I came up with an interesting syringe based solution to the problem. A servo would hold the syringe at the bottom of the range of motion of the actuator. The actuator would retract pulling the plunger and filling the syringe. The servo would then release the syringe and the actuators continued upward motion would lift the syringe clear of the source cup. The process would the be repeated in reverse to lower the cup and dispense the liquid.
When that seemed over complex, I developed a method of dispensing liquid that took advantage of a simple ball to choke the flow. when the ball was pressed upward by the motion of the cup, liquid would dispense, and liquid pressure would force the ball closed when the cup was removed.
In true brainstorming fashion, none of these ideas were selected, and instead we went with a "fountain" of tubes. I set to work designing and printing a bracket to hold all of the tubes pointing into the cup. I chose a collared design that would fit around a piece of 4" diameter cardboard shipping tube. The bottom portion of the collar had pressfit nuts into which the top portion would be screwed. The top portion had slightly undersized arches through which the tubes would be run.
I then assisted in assembly and debugging.