An upgrader loop allows people to use upgraders with no limit by using Teleporters or Reversible Conveyors to send ore through a loop with upgrades. After being fully upgraded, it's usually sent off into an "upgrade line." It is then collected by the furnace. Some examples are shown below.
The first stage(s) of the setup usually have cash limit upgraders, such as Suspended Refiners, Ore Thermocrushers, Ore Transistors, Ore Transponders, Morning Star etc., and sometimes there will be multiple cash limit upgrader loops because the upgraders of one loop cannot upgrade ore less than a certain value (the Ore Transistor and Molten Upgraders have this characteristic). This is by analogy, the first stages of the huge rocket. For Loop setups for rebirthing, this stage is often not used. Destructive limitless upgraders, most often BBBs or Dragon Blasters, can be put in a loop which saves resources on rebirth items, yet providing a large amount of money to the player. For setups for rebirthing, this is the first stage of their rebirth looping setup. Lastly, limitless upgraders, upgraders that upgrade ore no matter how they are worth, can only upgrade ores a certainnumber of times (Twitch-Powered Upgrader, Tesla Resetter, Ore Zapper, etc.,) are put in series. In analogy, it is the last "stage" of this setup/ and the imaginary huge rocket. This kind of setup, paired with BBBs, can be used in applications such as Quick Moderate to High-Level Rebirth Setup, getting the Overlord Device (DD), and getting the True Overlord Device (tsTG). For cash confusion, see Cash Suffixes.