Hi, I am a total beginner on all subjects of engineering, but I do want to ask here if it's the right place, about this project I want to do: I want to create a cheap (as cheap as possible, home-made kind of thing) piston that will simply move in a linear way in and out (about 40-50cm movement range). From my online research I found this is possible probably in the simplest way by a vacuum piston or air piston. I want to connect this piston, or the electric device that moves it, to an arduino board so that I can control the movement through that. Problems I am facing are: 1) If I activate the piston and have it create vacuum, how can I release that vacuum in a controlled way so as to repeat the process in a cycle without manually resetting the components? 2) What is the best way to connect (both electronically and physically) the arduino board to the electric motor or part that controls the piston? I would be very happy to know if someone has some ideas. Again, I am pretty much a novice in all of this so I am looking for a simple solution that I can create and understand by myself with cheap parts from ebay or some hardware store etc... Thanks!