Servo Valve

The objective of this design was to create a minimal-cost valve for lab-scale or small scale irrigation systems where water has to be diverted to many individual outlets.

It uses a cheap (~2EUR) Kuman KY66 mini servo to drive the actuator. This servo can be controlled and powered using only an Arduino or ESP-Devboard (some limitations apply with the 3.3V logic level), even though a dedicated servo driver is recommended.

Because the water is contained completely within the pinched silicon tube, the assembly is safe from leakage without the need for water-proof printing on a budget.

Important: The valve is for low-pressure applications only, e.g. with a water supply from a small water tank, or using a pump you can turn off, or a tap you can close using a proper shut-off valve.

Note: you will only one pair of levers provided, I have provided multiple versions to adapt to different tubes. Smaller gaps will increase the squeeze on the tube (see below).

Optional Use Cases:

• The valve can optionally be equipped with a second silicon tube. In this configuration it can be used as a source selector (e.g. for either fresh water or liquid fertilizer).
• By connecting both tubes to a small reservoir and opening the them in an alternating pattern, it is possible to deliver relatively precise amounts of water to the plants.