Strange edge quality issues

[Relentlesstaco]

Okay guys, first off, I'm not too new to cutting. I've easily run over 50 sheets through my 4x8 table with Powermax 65 plasma.
That said, I just recently started seeing some strange edge quality issues that I need to work out.
Air supply is good- double filtered, and dried with an inline desiccant drier, plus I live in Reno NV so theres not much humidity to speak of. I've run the same compressor and filtration system the whole time I've had my table, so I dont see any part of it being my issue.

Onto my issue-
I've been getting extreme bevel on 2 sides of my parts ( x-axis I believe), even with brand new consumables in the torch. Also seeing some intermittent strange edge cuts, it will cut nice and straight for 3/4 of the thickness of the plate (usually 3/16" steel, some 1/4") and then have a sharp bevel lip at the bottom of the cut. I've also seen the opposite, where it cuts nice and square most of the way through, then the bottom edge of my part is eroded and rounded inward. Any ideas?
I ordered some new consumables and tossed in a new swirl ring with the order, thought maybe that was my issue- a messed up/dirty swirl ring?
Any input or recommendations?

[jimcolt]

The swirl ring and the retaining cap....as well as e oring on the torch body can all affect cut quality.....as they all affect the way the air flows to the nozzle orifice as well as hrough the shield. Best bet is to change one component at a time and observe the effect. It is always a good idea to keep spares of the retaining cap , swirl ring as well as the oring.

Also....make sure your air pressure is set in auto....and I recommend installing a pressure gauge right at the rear inlet air line on your powermax so you can occasionally check inlet pressure while the torch is cutting. Sooner or later the air dryer/filter system will create enough pressure drop (while flowing) to affect cut quality.

Good luck...best regards, Jim Colt

Okay guys, first off, I'm not too new to cutting. I've easily run over 50 sheets through my 4x8 table with Powermax 65 plasma.
That said, I just recently started seeing some strange edge quality issues that I need to work out.
Air supply is good- double filtered, and dried with an inline desiccant drier, plus I live in Reno NV so theres not much humidity to speak of. I've run the same compressor and filtration system the whole time I've had my table, so I dont see any part of it being my issue.

Onto my issue-
I've been getting extreme bevel on 2 sides of my parts ( x-axis I believe), even with brand new consumables in the torch. Also seeing some intermittent strange edge cuts, it will cut nice and straight for 3/4 of the thickness of the plate (usually 3/16" steel, some 1/4") and then have a sharp bevel lip at the bottom of the cut. I've also seen the opposite, where it cuts nice and square most of the way through, then the bottom edge of my part is eroded and rounded inward. Any ideas?
I ordered some new consumables and tossed in a new swirl ring with the order, thought maybe that was my issue- a messed up/dirty swirl ring?
Any input or recommendations?

[Relentlesstaco]

Thanks for the help Jim. I always find your posts here and on Pirate to be informative and helpful
I did change out the retaining cap earlier today as I was having THC issues(they have come along with the torch issues, so i'm guessing they're linked) and came to find some dross blowback inside and a pretty chewed up nozzle after a just a little bit of cutting.
It cut better after the new cap, but still not 100%. I have a few o-rings on hand, so I'll add that in to the torch next and if that doesnt make much difference I'll finally replace the swirl ring to see if there is any difference with that if all else fails.
Also, how do you feel about a little dab of silicone on the oring to help seal?

[Relentlesstaco]

Well, replaced EVERYTHING in the torch and its cutting good as new again. Guess I'll keep a set on hands at all times to maintain cut quality. It was cutting a bunch of 3/4" bar stock this afternoon like a champ!

[Relentlesstaco]

Well, the good cut was short lived. Back to cutting poorly again, so I dont understand what it could be. All new torch parts and still cutting poor. My THC is acting up a bit which I know is definitely not helping, but even with THC off and cutting small parts I'm getting the concave edges again.
Any thoughts Jim?

[Relentlesstaco]

Bump>

Cutting a little better today but still not like it used to.
With the extra moisture in the air lately, could my filter system be the culprit? Would moisture do this to my cuts?
Also, I dont recall mentioning this before. It has been absolutely EATING nozzles. Like 20 minutes of cutting and the nozzle is shot, with a large tear drop erosion on one side of the hole. Getting expensive throwing so many nozzles at it!

[Gamelord]

I would seriously look at the moisture issue. If you are eating nozzles, that could be it. Once the nozzle goes, the cut can be anything.

[jimcolt]

If you post some good pics of the business end of a used electrode as well as the inside and outside of a used nozzle....it will help me try to determine your issue.

Moisture, oil, particulates or starvation of the air system can all have dramatic effects on nozzle and electrode life. Often I find users with too many filters/moisture traps in their systems that start to reduce inlet pressure to the plasma under flowing conditions. When a paper filter gets saturated...it simply cannot pass the full rated flow, so under flowing conditions the inlet pressure can drop. I alway have an inlet pressure gauge mountd directly on the plasma air inlet (see pic). If your gauge is 20 feet away....or back at the compressor it will not see a pressure drop....if at the plasma I guarantee you will see the inlet pressure drop every time the air flows to the torch.

Moisture and oil and particulate in the torch change the chemistry of the plasma gas.....which changes its electrical resistance. This can (and does) cause the arc to go where it is not designed to go...and easily (at 25,000 degrees F) can melt copper that has a liquid temperature of around 1000 degrees F. Moisture tends to get trapped in fittings and bends in a plumbing system...builds up and releases in "slugs"...which can explain why sometimes the system works ok....then all of a sudden consumables can fail.

Jim Colt

[Relentlesstaco]

Jim
I'll pick up a gauge for the back of my plasma like you recommend and keep an eye on PSI there.
Here is a picture of some consumables from last week that were pulled after a little bit of cutting.