The final mechanism to test on ThinBot was the circulation chiller system. Rather than deal with delivering ice and/or shaking/stirring, I'm chilling all the ingredients via chilled water circulation (an idea I happily admit stealing from the iDrink 'bot at last year's BarBot).
From a thermal reservoir (ice chest) of ice and water on the floor, the design calls for a fountain pump to fill the chiller/nozzle assembly, which will then drain into the upper bottle tank, which will drain in turn into the lower bottle tank, which then drains back into the reservoir. This will cool the spirits while adding visual interest as a table fountain. In theory, any way.
Satisfied that ThinBot could actually deliver cocktails, I moved the whole thing outside to test the circulation. If anything went horribly awry (or the aquarium sealant failed) I wanted it to happen someplace where it wouldn't cause damage.
Here's video of the first test:
Good news: it worked (after adjusting the length of the chiller/nozzle tank drain line slightly), and the fountain pump is sized perfectly (it's rated to lift a column of water 4 feet, which is perfect when ThinBot is on a standard-height table). Bad news -- the stream draining from the upper bottle tank to the lower tank splashed enough to spatter the table significantly.
On to try two -- at bovil's suggestion, I suspended a length of ball chain through the upper tank drain to just above the water height in the lower tank. It worked beautifully, quieting the splashing but still delivering the falling water sound.
In the home stretch now!