Pinch Valve

Intro: Pinch Valve

This is a simple way to control the flow of water via a microcontroller or similar. Most commercial irrigation valves require a certain amount of water pressure. This valve is designed for low water pressure. It is used in the eRiceCooker project, a fully automated system that cooks rice according to the frequency of news reports about genetically modified rice.

STEP 1: The Parts

You will need:
- A servo motor
- Enough flexible latex tubing, outside diameter 3/8" (medical supply store)
- Metal pipe outside diameter 1/2" (home depot)
- Four zip ties (they can be a bit wider than the ones pictured)
- two tiny screws & bolts
- Flat material which can be cut, sanded and drilled (plexiglass, wood, aluminum, etc.)

STEP 2: Assembling the Parts

This is how the fully assembled valve looks from the front.

STEP 3: Assembling the Parts

This is how the assembled valve looks from the back.

Assembling the valve is really very simple:
- Cut the metal pipe in two even-sized pieces.
- Cut the plexi (or other material), so it forms an oval.
- Drill some holes in it, and attach it to one of the servo motor's arms using the screws.
- Push the latex tubing through the pipe-parts
- Attach the pipe-parts to the plexi.

STEP 4: Open Valve

This is how it looks when the valve is open and the water flows.

STEP 5: The Valve in the Context of a Larger Project

Once you've assembled and tested the valve, you can add some water.

Comments

[Zarg404]

Hi Annina,
I have a question for your "old" Pinch Valve project. What was the dispersion of the water volume you needed each time you used your valve ? How quick does it stop the water flow ? Thank you

[ScarlettP2]

Hi :)

How do you control the servo motor? Can it be done with an interface such as RedLab 3102?
How many outputs are needed to connect to the servo motor? And what kind of signals does it need to receive so it can open/close?

I have no experience at all in all this, sorry in advance if my questions seems stupid.

Thanks for your help!

[annina]

I recommend this:
https://www.arduino.cc/en/reference/servo

[maker12]

I HATE MICRO,S (all haill nash for non micro based ic,s)

[VelvetElvis]

Nice photos! I wish all Instructables were this clear.

[cheesy]

Any suggestions on where to get cheap servos? Also, tips on hooking them up to microcontrollers?

[bluelip]

Check your local RC/Hobby store. I picked up two Futaba S3004 servos last week for $13 each. I thought it was a good deal since the last time I bought a servo, a few years ago, they were over over 20 bucks each.

[trebuchet03]

oooo -I like that microcontroller setup (except it requires a programmer for initial setup :P) That site is acting a bit flaky (not sure if it's my end to blame) - I've been wanting to get into microcontrollers and I think this is how I'm going to do it (fits the budget :P).

[Myself]

Allow me to plug the Serial Wombat here. I picked one up a few months ago at Hamvention and it's pretty sweet: A programmed PIC that can act independently, but is mostly an I/O peripheral for your PC. It's incredibly easy to do tasks like drive steppers and servos, read encoders and pots, and control LCDs.

[rimar2000]

Excellent.

[Crash2108]

I was going to make an automated risotto maker.

[LasVegas]

Love the automated rice cooker. Now can you make an automated potato masher? Or, better yet! an automated port roaster for every time a federal bill is passed.

[ARVash]

Rofl XD. i like it :3