Pinch valve: Gear motor rotates lead screw, moving nut (and attached slide gate) up and down. Lowering the gate pinches 1″ I.D. Silicone rubber tubing shut. Raising it, opens the valve. The L298N H-bridge motor controller provides a simple inexpensive way to reverse the direction of rotation of the motor. (see also earlier rough ideas at Arduino stepper motor controlled slurry pinch valve)
- Able to handle solids / slurries without clogging. No moving parts in contact with liquid, no maintenance.
- Inexpensive: computer controlled automation for < $100/valve.
Resources, details / how-tos:
- Gear motor specs: 30 RPM Gear Motor.pdf
- Instructions on how to Control-DC-and-stepper-motors-with-L298N
- More instructions on how to Control DC and Stepper Motors With L298N Dual Motor Controller Modules and Arduino_ 3 Steps
- 3d printing service: https://www.3dhubs.com/3d-printing