In real life (IE when you go to apply your engineering skills to tasks in industry) there will be constraints on all sorts of things - many of which may or may not be "fair" or even "intelligent". You must learn to either work around them or use them to your advantage - preferably a bit of both. - OScubed [more]
Power Point Slide from our team CDR (Critical Design Review) that shows pneumatic circuit and solenoid switching to allow variable point positioning of the circuit.