Drink Mixer (precise liquid dispensing)

So I just got a largely unnecessary yet hugely awesome idea in my head: I want to make an arduino controlled cocktail mixer. If you guys have ever seen the device called "The Inebriator" (The Inebriator - Arduino Cocktail Machine - Dispensing Signature Cocktail - YouTube), essentially I'm going for something like that. Now I'm not trying to rip them off or anything, I've got no plans to try and commercialize this. I just saw it and decided I want one for myself. Plus their design seems a little unnecessarily complex, why not just run tubes to one central point and get rid of the moving parts altogether? I've got all the details worked out in my head except for one part. I don't really know how I could control my liquid volume. It seems like they've got some sort of fixed volume valve on theirs, but I couldn't find anything like that after some google scouring. Anyone have any sources on those things? Or any better ideas on how to consistently dispense liquid of varying viscosities?

See:

You think I could just calibrate it by hand? That might work. Do peristaltic pumps provide a consistent flow rate from one actuation to the next? Only thing is that's awfully pricey for just one pump. I'd need at least 10 if I went that route.

edit: After some more intense late night googling, it seems peristaltic pumps can be had relatively cheaply on ebay (about 10 bucks). However, the general consensus is that they're pretty slow. I don't want to make something that takes 5 minutes on a single drink. I also found out what the valves are on "The Inebriator"; they're called optics, and they are apparently standard bar equipment. However since I'm not a huge fan of either of those options I'm still wondering if you guys have any other suggestions.

I think you will find it very difficult to equal the visual appeal of "The Inebriator".

Using the peristaltic pumps, the speed is no great concern because you would dispense all the ingredients simultaneously, with the added advantage that mixing is effected at the same time.

Here's a thread on the same topic http://forum.arduino.cc/index.php?topic=249364.0

There's a link in there to the drinkmotizer, which does the same job but uses linear actuators to work the optics rather than raising the glass.

Optics seem like a good solution - what's giving you pause there?

How about this:

http://www.ebay.com/itm/Water-Flow-Sensor-Fluid-Flowmeter-Switch-Counter-0-3-6L-min-for-Imprinter-T1K-/380746990720?pt=LH_DefaultDomain_2&hash=item58a64a0480

and a solenoid ??

the flow sensor is essentially a paddle wheel, that give 'x' amount of pulse per rotation. knowing how many pulse for 'y' amount of liquid, you could control the duration of the solenoid's opening ....

Paul__B:
I think you will find it very difficult to equal the visual appeal of "The Inebriator".

Using the peristaltic pumps, the speed is no great concern because you would dispense all the ingredients simultaneously, with the added advantage that mixing is effected at the same time.

I think I would find it difficult too if I thought I could do that haha. I really like the way theirs looks, but it's pretty unnecessarily complex and far too big for my purposes.

Even with simultaneous dispensing, often a drink will require a few ounces of the same type of liquid. Given that the fastest I could find for a reasonable price is 100 ml/min, or about 3.4 ounces, that's not really ideal. I can't have it take 20 seconds to pour a shot, so I think that's out. Unless of course anyone has a good source for cheap, fast pumps. Also wouldn't you still need a solenoid of some sort to cut off the flow? Or can the pump be used as a solenoid of sorts? I know how a peristaltic pump works but I'd be concerned about how well it can seal against gravity flow.

wildbill:
Here's a thread on the same topic http://forum.arduino.cc/index.php?topic=249364.0

There's a link in there to the drinkmotizer, which does the same job but uses linear actuators to work the optics rather than raising the glass.

Optics seem like a good solution - what's giving you pause there?

Never would have thought of door lock actuators. Good find! I was thinking servos with wheels on them and a string between the wheel and optic, but that's much simpler. I suppose what's giving me pause with the optics is just finding the damn things at a reasonable price on US soil. Everything I found was either Britain, Austrailia, or overpriced. Plus I'd be looking for the kind that just has one lever you pull back, not the three prongs you push up, which is even less common. I might end up having to do what the drinkmotizer guys did and buy a couple oggi drink carousels. Also I'd like to be able to dispense less than 25 ml at a time too.

Jouellet, that was one of my first ideas. However, I'm just guessing you shouldn't be running things you're going to eat through that flow sensor. Plus it bottoms out at 300 ml/min.

tboneh:
I think I would find it difficult too if I thought I could do that haha. I really like the way theirs looks, but it's pretty unnecessarily complex and far too big for my purposes.

But that is the whole very point of the thing! XD XD

tboneh:
I know how a peristaltic pump works but I'd be concerned about how well it can seal against gravity flow.

Well, if you know how it works, you will know that it absolutely seals against gravity flow. That's exactly how it works.

Any pumped system will, of necessity, leave your bottles open to the atmosphere and, therefore, ingress of dust and evaporation of the alcohol.
With optics, the bottle is sealed at all times except when dispensing. This allows no evaporation and, as the inflow of air is upwards, little chance of dust entering the bottle.

See the same pump here for less:

I use these for Chlorine dosing my swimming pool twice a day under Arduino control.

Low voltage by the liquid stuff is a good idea!

I run mine with a little 12V power supply like THIS:

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