I am new to cnc plasma cutting. My table is a home built. The problem I am having is, when I cut a square one side always is rougher than the other 3 sides. I can see and hear the torch cutting differently going this particular direction. The 3 sides that are cutting good and smooth sound like a hiss of the plasma. The bad side sounds somewhat like a rhythmic vibration hiss, like if you cross a rattle snake sound with a plasma

. You can also see the torch somewhat flicker on that side.
This problem is very consistent. Anytime the machine cuts in that direction this happens. I am wondering if it has something to do with my slats being bowed in that direction?
Any thoughts would be appreciated.
Thanks, Travis