Cause of poor cutting?

[Metriccar]

My plasma cutter will go through dry spells where it simply can't cut all the way through the metal.

Right now what it's doing, 14 gauge, using manual settings, fine tip consumables. It will go for lenghts of time without actually cutting all the way through. I will check the height using feeler gauges, it's cutting at 0.06" The desiccant in my filter is colored indicating it's not wet yet. I have 130 PSI at the back of the cutter.

[chasxjs]

What plasma cutter are you using and what speed are you cutting at?

[cbassjr]

OK let me see is I can help.

Diag.1. I have had similar problems and I tried everything and when I posted here I got a reply that it was possibly bad metal. Called my suppliers and they assured me it was USA metal. Soon afterwards I was looking through some other sheets and found Mexico stamped on one of the sheets I had bought at the same time and every time I cut one of those sheets I have a similar problem.

Diag2. I was having a similar problem recently and if you are using mach 3 next to where you key in your cut temp the is a square button that unless you click that also you are not cutting at the correct temp you keyed in.

Dia3. It could be as simple as a grounding issue.

My 2 cents. Hope it helps. Understand my wife says I don't know s*&t. So proceed at your own risk.

[WyoGreen]

Sometimes it's the simplest things. I needed to build some new press plates today for my hydraulic press. I had a length of 1" x 8" steel, so I figured I'd use it. I have a HT45 so 1" is at the top of it's capacity using edge start. First try it wouldn't cut thru the 1" no matter how slow I went. So I double checked everything, whoops, the amp dial on the HT was turned down to 30 amps. Tried again, still no go. So I checked my consumables, small pit on the nozzle. Changed out the consumables, and wa-la, that 1" cut like butter (cold butter). Made my 10 cuts with no further trouble at all.

So, moral of the story, check every thing twice, and be sure your consumables are in good shape. If nothing else, just change them out to see. Make sure your plasma cutter is set up right. Make sure your ground clamp is on good. Make sure your air pressure is where it should be while air is flowing out the torch.

Steve

[Shane Warnick]

I have a new pm85 that does the same thing. Only with finecut consumables. Standard nozzles I cut at book specs. Finecut, I HAVE to cut at 0.080 height, and about 93-95% of book speed. Damned if I know why. I checked height, everything. For instance book spec on 45 amps for 14g with finecut is cut @220 ipm and 0.060. About 30% of the time it skips and just gouges, then drops back through and cuts fine. Pierces are good, but the skipping / gouges occur at random. Dropped the speed to 213 ipm, had more angularity than I wanted but essentially dross free. Bumped cut height to 0.080 and voila. THC holds it 0.075-0.080 and it cuts like a dream. Same exercise with 10g and finecut. Drop speed raise height otherwise it randomly doesn't cut all the way through. Adjust settings and bam no dross and clean nice cuts. I also found that at 0.060 cut height I had some top dross as well, but not a ton. Just my experience.

Shane

[jimcolt]

I find that with Finecut nozzles (Powermax85) I run at book specs...except for height. I find more consistent cut quality at about .075" height (vs the cut chart .060). I have spoken with our process engineering group about this...they will be looking into it.

As far as cutting 1" with a Powermax45......you are pushing the limits of thickness....consumables must be in excellent condition to do so. a small nick in the nozzle orifice reduces energy density in the arc, and when cutting very thick materials all bets are off!

Best regards, Jim Colt

[Metriccar]

It turns out it was the desiccant.

[ATPPF]

Were the beads wet or dirty? or was it cutting back on volume of air? I seem to be having a similar problem and am chasing my tail.
thanks

[Metriccar]

The beads were pink instead of blue. When I baked the desiccant, they turned back blue, and the cutting problem went away.

I have found it's just critical to have clean, dry air for this thing to work. Plus I keep it at 130 PSI. It doesn't like low air pressure either.