This is a simple design to allow a servo to act as a single pole changeover switch for fluid or gases.
Assume flexible tube similar to that used in fish tanks.
Theory of operation: As seen in the video, the servo will move from the one side to the other. On either side it will push into a pipe and cause the pipe to be crimped and therefore no water will flow. When one side is blocked the other side will be free to flow. Therefore its operation is analogous to that of a single pole changeover switch.
There could be many uses for this mechanism however my intended use is for a simple, two servo precision pump. I will post a link to this pump once I create the instructable.
This can easily be laser cut out of perspex or 3D printed. The brave may attempt to make it using a rotary tool!
Step 1: Solidworks Files
I have attached the solidworks files which can be used or adjusted for other pipe sizes.
Step 2: Recommendations
This is a crude method to crimp the pipes. By just using a servo arm as the crimper, one is limited to small pipes. To overcome this just 3D print or laser cut little discs which attach to the end of the servo arm. These will block the pipes better and can be adapted to slightly larger pipes.
Comment on other uses for this mechanism! And Enjoy!