Uh oh, what did I do? (Plasma cutter)

I've had a plasma cutter for a couple of years, but I've always used it for thin-ish stock & briefly. That is, duty cycle has never been an issue. Until today. Today I made an 18" cut in 1/2" plate. With a

3/8" capacity cutter. It is spec'ed to "sever" 1/2". And it did, but slowly & with great ugliness!

Anyhow, I knew that I was pushing it, but I figured that the "overheat" limit would kick in if it was too much. It didn't, so great. Afterward (!) I dug out the manual & checked: 35% duty cycle at max amps. Uh oh.

So, the question is: was it OK to rely on the built in overheat limit, or did I need to stick to the 35% duty cycle? And since I didn't (and it's still running), what might be the consequences? Shortened life? I did let it run quite a while after I finished the cut.

Thanks, Bob

Oh - it's a Hyperthem "powermax 380"

Reply to
Bob Engelhardt
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How long did it take to make the cut, more than 3.5 minutes? If it's a Hypertherm it's probably just fine.

Reply to
Pete C.

Probably 10 minutes total - I fooled around trying different techniques, which took longer than just doing it.

I just thought of this - the cellar's temperature is about 60F, so that probably helped some. I.e., cool enough to keep the cutter's temp down.

Bob

Reply to
Bob Engelhardt

I have a 600 and it seems to work fine. I cut 1/2" AR400 BHN400 not Fine cut parts will cut 1/2" better - higher density of beam and less to blast through.

I suspect the electronics was on watch guard all of the way. Don't sweat it.

I heard my SD 180 TIG/Stick turn on the fan yesterday - didn't recall hearing that before. I suspect it got hot. I was doing stick welding and it was 90. I was glad to hear it - know it still works :-)

Mart> I've had a plasma cutter for a couple of years, but I've always used it

Reply to
Martin H. Eastburn

I have a 600 as well. I considered buying the fine-cut kit but was put off by it only being rated for really thin stuff. Would you please elaborate a bit on the pros and cons of the fine-cut consumables?

Wayne

Reply to
wmbjkREMOVE

The only difference between fine-cut and regular is the kerf size. The fine-cut has a smaller kerf so it can cut out more details. I think they mainly are made for plasma tables.

GWE

Reply to
Grant Erwin

The beam of say 40 amps comes out of a hole through metal and to a return.

Now consider washers. A 40 gallon/min flow through a 4" hole in a washer moves but it has so much area the density or electron/area is lower than that of a 1" hole carrying the same flow. The pressure increases...

The fine cut kit is a quality kit. I also use the pipe cutting nozzles with it - but on sheets. The pipe ones are much like normal nozzles. The normal fine cut ones are chrome plated (or Nickel maybe).

I use the fine cut and normal cut consumables as I need differences - but almost always fine cut.

I know - it isn't rated for thick stuff by Hypertherm corp - nor do they say much about copper or Aluminum either. When not said - I experiment.

Having a good dry air also helps a great deal.

Mart> >

Reply to
Martin H. Eastburn

Your analogy is clear and makes perfect sense. I am only repeating what I was told recently by a Hypertherm application engineer doing a welding supply open house here in my town. He sounded like he knew whereof he spoke .. anyway, I know you have gone deeper into plasma cutting than I have, and I certainly defer to your experience.

Uh, I don't think I've heard of pipe cutting nozzles, not for e.g. a Hypertherm Powermax 1000.

Grant

Mart> The beam of say 40 amps comes out of a hole through metal and to > a return.

Reply to
Grant Erwin

Thanks to you and Grant for the info. I'm going to start shopping for the kit. As I recall, it was actually pretty reasonable.

Wayne

Reply to
wmbjkREMOVE

The nozzle is for the small torch on my 600. My T60 uses standard parts.

I believe, web info changed - now says extended not pipe. I think there was a pipe cutting attachment that the head locked into - and it ran around the pipe. Long nozzle needed long electrode from the fine cut kit parts.

120574 Electrode Extended***Sold in sets of 5 If I have it correct - have to check in the shop.

But alas nothing for the R60/R80.

Mart> Your analogy is clear and makes perfect sense. I am only repeating what I

Reply to
Martin H. Eastburn

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