We put in 23 pulls on Siegecrafter over the course of about three hours last night, but were unable to down him. We got him low (sub-10%) a handful of times, but we were scrambling by the end of each pull. I'm very much getting a feeling of panic from several of our raid members, which I believe is causing some basic mistakes and leading to our wipes, but I'm hoping that someone can have a look at our logs and see if there's anything totally obvious we're missing.
It seems that on most pulls we have either a healer or tank death fairly early on in the fight - usually around the time the first magnet is allowed through on the belt. It's usually our warrior tank that dies at this point, but that may just be due to the tank rotation in the fight. Our pally pulled first on every pull, so maybe he's not being put in the same situation as our warrior which is why we aren't seeing the same kind of deaths from him. I really don't know anything about warrior tanking, so I'm having trouble analyzing his death logs.
We use (what I think is) a pretty standard strategy - the ranged/healers are mostly stacked, dropping sawblades and fire to the side of the group. When it gets a little too crowded, we shift the ranged group and the boss to the side so that we have more room to drop stuff. After/during the first magnet, we reposition in the same general location as we were when we started the fight, repeating these motions as necessary. Belts did not seem to be a problem for the most part. We have a fury warrior soloing a belt and a rogue or a hunter (we switched it up as the night went on) on the other belt and we only got a shield a couple times.
If anyone would care to have a look at our logs and offer any advice, that would be greatly appreciated!