Me and Tautha made a cobblestone generator recently using pistons and some very elaborate timing. Since then i have redesigned it so that it uses no timing outside of the cobble block generating. Detector 1 tells the wall of pistons shown to push forward once when it is full of cobble. Detector 2 turns off the entire machine when the generator is full, the power switch does the same, but at any time. With this design the wiring is also much simpler, and it causes less lag for single player and servers, because only one set of pistons is moving at a time, not all of them constantly moving like the original.
