Plasma Help

[Cbake]

First off let me say hello to everyone as I am new to the site and this is my first post. Now then, I picked up a Miller Spectrum 500 last Friday for $400 including a small box of consumables. It worked fine when I tried it at the previous owners shop when I tried it on some 1/8" plate. I am totally new to plasma and have no experience with it. I went to use it to slice a new piece of exhaust tube the other day. It started fine and ran fine until the main arc kept going out leaving just the pilot arc. I tried adjusting the air pressure and distance and it didn't seem to help.
Sorry for the long first post, but any help anyone can give is hugely appreciated.

[NVW]

Sounds like a bad ground to the work.

[Cbake]

Is there a minimum thickness a machine like this can not go below?

[NVW]

Originally Posted by Cbake

Is there a minimum thickness a machine like this can not go below?

No there isn't, the thinner the faster you can travel. The amps should be set for the thickness of material being cut, the manual should give you a chart.

Leo

[Cbake]

Ok, I was on the low setting and it would cut fine for 1/2 inch then loose arc. I was using the standoff for the high range can the tip touch on the low range? It was like it would go out after i couldn't move fast enough to keep up with it.Sorry for the questions, I am completely new to plasma)

[NVW]

Sorry, I'm not familiar with your machine.

With my Hypertherm if I go too slow I will lose the entire arc.

The way you first described it, it still sounds like the ground is losing contact. I have started to make a cut only to realize the ground clamp isn't on, I will have my pilot arc but all that happens is the work is etched for lack of a better description.

Try it on a higher setting and increase travel speed.

[Cbake]

Ok I got to play with it some today for about 45 minutes, and because my only power source was the generator for 240v I ran it on the low setting. I moved the ground much closer and cleaned the metal better. I took the 1/8 stand off guard off and put the nozzle on the 1/8 plate and it cut right through like butter. I think I figured it out. Thank you a lot for the help it really did get me going in the right direction.

Thanks, Caleb

[NVW]

Glad to help, with time spent with it you'll learn more & more.

[ed mac]

Originally Posted by NVW

Sounds like a bad ground to the work.

you need a good ground if your working with painted
steel grind the a spot for the clamp