After you start the generator, continue with the stage. Wait until you get to the end of this room. Do not go through the door yet. Because the lights are now on, you will see two platforms above you. Note: The second one may be difficult to see. Use somebody that can jump high to reach the Rare Metal on the second platform.

After turning on the generator with Thunder Dancer or the Plasma Gun, walk out of the room you are in. Instead of falling to the lower level, double back where you came from. Notice that there are ledges to jump on top of. Use Zero to keep jumping the ledges to get to the Rare Metal.

Once you have Gigabolt Man o' war's Weapon and the Metal Generator you can buy at the lab for 5,000 Metal, bring Axl and anyone else, with anyone as the navigator. Have Axl copy a guard in the level and reach the generator. Once you are there, you can keep walking into the generator without stopping. With the metal generator you will gain 24 Metal every three seconds.