Sandbox and Flux RCDs by each-other
RCDs (Rapid Construction Device) are auto building machines, Flux RCDs require fuel and are obtainable on test and production, Sandbox RCDs require no fuel, but are slower without patron and test only. The RCD has a 10% of being dropped by green bots in sparrow, and can be used to build layout from the [blueprint scanner] .
Additionally there are certain items that the RCD cannot build: Launchers, doors, spawns, signs, paint, lockdown override units, and other RCDs.