Read this on MMoChampion so I dont know if it is true or not
QuoteProTip: Tank boss on far left side of the room (left if you are facing the boss) between the 2 piles. The adds will only then spawn from the piles in the far right side of the room, giving you all day to kill them before they reach the boss.
Might be worth a shot to try out.
we got him in 10 man last night, right at the nick of the enrage, but I think instead of using what sounds like some kind of terrain exploit that makes it so the stuff wont spawn, you have ranged with aoe take care of the scrapbots and then burn down the other adds, while the melee sticks on the boss so you dont end up meeting the enrage timer.
we kind of did that in 10 last night, but we were melee heavy so most of us were doing both.
The increased the time of his enrage timer today so I guess this wont be necessary