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.