How do I kill The Spire's Heart in the Golem Factory? I've cleared all 4 golem spires, but I can't actually damage the final boss of the factory, he's immune to everything.
Edit:
I've currently got the factory control panel set to:
Furnace Draw: Pull
Generation Intensity: Medium
Approach Paths: FL-2
Shielding Lower: Off
Grid Alpha: Off
Shielding Upper: Off
Grid Beta: Off
Generator Fuses: Offline
Grid Star: Off
Thalen Intensf.: High