I'm seriously considering buying a 35 amp plasma cutter with a 40% duty cycle. It's an inverter-based model, but I won't mention the brand since I don't want to start a brand-war :-P
Anyway, what should be my realistic expectations for it's cutting capability? The specs say 35 amps will clean-cut up to 3/8" thick mild steel. Should I expect that to be accurate? Will it cut 3/8" thick without needing any cleanup of the cut edges? If not, what's the likely max that I can cut cleanly enough to not require any grinding? I've read on plasmacam's web-site (www.plasmacam.com, a small CNC plasma cutter table) to expect to need 25 amps for every 1/4" to cut cleanly. Does that sound accurate?
Also, assuming 35 amps will cleanly cut 3/8" thick steel, is this starting from an edge, or starting somewhere in the middle of the plate? In other words, can I only cleanly cut 3/8" thick starting from an edge? If so, what's the max I should expect that I can cleanly cut if starting from the middle of the sheet or plate?
And, at a 40% duty cycle, should I expect that to seldom kick off on me? Seriously, I intend to cut shapes out of reasonably thick sheetmetal (up to 1/16" most of the time), but if it cuts fast enough, I could certainly see using the plasma cutter rather than bandsaw to cut out small things like mounting plates, or for quickly cutting 3/16" by 1/2" flat stock into exact lengths (I'm using this size mainly for forming scrolls).
What is the max size that I can sever? I've seen other 35 amp units that say you can sever up to 1/2" thick. Should I assume that's true of this unit even though the specs don't mention it?
This unit doesn't have a "stand-off" nozzle (meaning you have to use your human dexterity to keep the plasma torch the right distance from the workpiece), but I can't see why I couldn't bend some round stock into a simple "stand-off"...or would that cause the arc to jump to the stand-off rather than the workpiece?
Any advice much appreciated!
Dave