Intoxicated Timesharing System

March 29, 2006 3:19 PM

Where can I find several small, clean solenoid-actuated valves for a modest sum? For making an automatic drink-mixing computer.

I need a set of eight or so solenoid valves. These valves will open and close to regulate the dispensation of liquor as controlled by an old PDP-11 we got operational. But, when I google, I get back fuel solenoids (too big) or precision solenoid valves (too expensive). I just want some little, electronic-controlled valves. Can't you help?

Imagine that they would hook into tubing of the approximate gauge and flow of aquarium tube. Perhaps a little thicker would be better.

I'd like to pay no more than $10-20USD for each one. I'm glad to rummage. What should I be looking for? What can I pull these out of?

posted by Netzapper to Technology (13 answers total)

Best answer: I would imagine there are solenoids that would be appropriate in door-mounted refrigerator water filters. I'm not sure how you would go about finding eight unused refrigerators though.
posted by Bondrake at 3:36 PM on March 29, 2006

On further review, a search for refrigerator solenoid valves turns up some interesting results. See if anything looks useful to you.
posted by Bondrake at 3:41 PM on March 29, 2006

omg. post this to project when you are done. so awesome.
posted by fishfucker at 3:44 PM on March 29, 2006

Best answer: sciplus.com has solenoid valves for 7.95 each (scroll down) they also have windshield washing fluid pumps I'm not sure if either of them are clean enough for drinking though. This forum will probably be very helpful for your project.
posted by harrigton at 3:57 PM on March 29, 2006

Wheel 1, wheel 2.
posted by kcm at 4:01 PM on March 29, 2006

You need food grade valves, especially with the alcohol. Here is one that is not particularly cheap, but you might do a little better with some searching.
posted by caddis at 4:04 PM on March 29, 2006

McMaster-Carr has some that are about $20. Part No.s 7877K6, 7877K5, 7877K3, 7877K2 (catalog page 420).

If you want cheaper prices, look to surplus. Google "surplus electronics" and then go from there. Here are some examples:

Solenoids - Air / Liquid
24VDC 8Watt 85-PSI Max NICE SOLENOID VALVE 1-In 2-Out ports P-B-A terminals - NEW - 1.25inchsquare x 2.9inchL
N C 240VAC SOLENOID VALVE W/ 1/4inch MPT BK-12930-137
240VAC 60CY. 10WT.SOLENOID VALVE 250PSI 3/64 ORFICE
SOLENOID VALVE, 24VDC PNEUMATIC
posted by Rhomboid at 4:14 PM on March 29, 2006

How would you feel about absolutely precise fluid metering for no money?

Epson inkjet printers have a neat little peristaltic pump that sucks waste ink out of the parking pad (other brands may have these too, but I've actually clapped eyes on the Epson ones). Epson printers are notorious for clogging and being expensive to fix, so you shouldn't have much trouble finding eight discarded ones.

The pumps are driven by the same stepper motor that handles the paper feed, so making the PDP-11 drive them should be pretty easy.
posted by flabdablet at 6:32 PM on March 29, 2006

I would totally spring for some food grade pumps if you were going to do this. And I would definitely not use the discarded printer ink pumps.
posted by TheOnlyCoolTim at 7:19 PM on March 29, 2006

The beauty of a peristaltic pump is that it works simply by squeezing fluid along the inside of a tube. The fluid doesn't contact anything other than the tube itself.

So if you just go out and find yourself a supply of food-grade silicone tubing that's about the same size and wall thickness as the short length that's built into the printer, you can just run that straight through the pump mechanism on its way from the reservoir to the dispenser. Instant free food-grade metering pump.
posted by flabdablet at 7:59 PM on March 29, 2006

Small Parts is also a good source for things like this. I love their catalog.
posted by mrbill at 8:48 PM on March 29, 2006

Ah, yes peristaltic pump...
posted by TheOnlyCoolTim at 10:14 PM on March 29, 2006

If anyone is interested in the other end of the cost spectrum: MKS Instruments makes precision fluid handling devices.
posted by Kirth Gerson at 3:53 AM on March 30, 2006