My boss has a boat load of extra PVC piping laying around the shop and I wanted to use it to make a pipe organ. I need a way to electronically open and close the connections from each individual pipe to the main air supply. I'm on a tight budget and I'll need to make 88 valves in total. I have found a few valves online but they are far to expensive. I was hoping I could find a way to make a cheap electronic control that could achieve this purpose. I am inexperienced with electronics and am in need of as many ideas as I can get. Here are a few points about the design that might be helpful: PIPE LAYOUT [1.] I plan to have each pipe sealed at the bottom with a cap (all though, buying 88 caps may be too expensive so other options are welcome) [2.] I plan to drill a hole in each cap and attach surgical tubing or something similar. [3.] Pipes will be grouped into sections (I'm thinking four groups: bass octave, low range, mid-range, high range) [4.] Each pipe in a group will be connected to a "parent pipe" which will be sealed at one end with a cap and the other end with an electric fan. [5.] The four parent pipes will produce differing air pressures to accommodate the change in pipe sizes. CONTROL SYSTEM [1.] I plan to recreate a simple keyboard with 76 wooden keys that 'see-saw' over a wooden dowel rod that will run through each key. [2.] I plan also to do something similar to create 12 foot pedals (for the bass octave). [3.] As each key is depressed, an electric switch is actuated (still not sure exactly how I am going to set that up) [4.] Each switch will correspond to an electric valve that is located on the parent pipe of the note depressed, and will allow the air to flow from the parent pipe to the tubing, and thus sounding the flue pipe itself. This design is in a very early stage and I am certain changes will be made as issues arise or are brought to my attention. For now, I need to figure out the cheapest way to control the air flow electronically.