that could be part of the problem. Most of what I cut is 3/16 and 1/4" plate once in a while some 1/8" or 16 ga. In post #41 here I use alof of these as good starting points
http://cnczone.com/forums/showthread.php?t=26227&page=4 I have to keep my THC at around 138-140 sometimes though or it will crash. It used to crash alot more than it does now. And would any moisure in the air effect the thc as well? I have like 3 water traps on the line in different places before it goes into the plasma. I thought about taking a big tote bucket of cold water and tossing the coiled up hose in it to see if it helps reduce moisture as well as a temp fix. I wish I had the $ for this thing lol
http://torchmate.com/air_filtration_system/index.html