Minecraft wiki entry for Instant_repeaters, associated text: You have several flying machines that all need to move at the same time, or else they will get stuck to each other and break. This situation can be resolved by starting them all up at exactly the same time, using redstone. Instead of using an ordinary repeater to keep the signal going (which adds 1 tick of delay, possibly breaking the machines), use an instant repeater to ensure that they stay synchronized.