Originally Posted by
Peepers
This is my first post and a somewhat desperate one.
I built my plasma table about a year ago and have been very luck to have had no real problems until last week. I cut art stuff from 16 ga steel.
My setup consist of Mach 3, SheetCam, THC300, and a Hypertherm Powermax 1000. I cut 16 ga steel using Finecut consumables at 250 IPM, .13 pierce height, .065 cut height, around 32 amps and 85 psi air pressure. My tip voltage is around 48 volts but is only good for my reference as the THC meter is not calibrated correctly.
These settings are the result of a lot of testing and have produced very clean
and slag/dross free cuts.
I know the manual says .08 cut height and 150 IPM at 40 amps but I found I got much cleaner cuts at my own settings.
The problem I have now occurred after I cut 10 or 12 nested pieces which cut perfectly. I loaded another file of nested parts all from the same post processor setup. I indexed to my start point on same sheet of steel and started the process. The torch has no problem piercing and the cut starts. Randomly the arc will bounce up form the steel and not cut this may happen for an inch or two or it may five or six and then continue to cut fine for a while and then do the same thing not cutting through.
It does not matter whether the THC is on or off or if it is a straight cut or a curve. I have tried slowing down cut speed, increasing current, changed consumables, just about everything I can think of and nothing has worked.
I have not been able to figure out if it is the plasma cutter or what.
Any ideas or suggestions will be appreciated.