why do I keep getting this ?????

[Dustan]

hi all I will get right to the point I have a TD A60 with machine torch on a fastcut cnc table everything is good except I was having poor quality pierces put a new nozzle and it works again for a few pierces then puts the tip out of round and doesnt pierce worth a dam I thought it was moisture so I went all out and bought a DeVILBISS 3-stage dessicant dryer and theres nothing getting by those filters my air is now not and issue at all ok cool but im still wrecking consumables in record time you can actually hear the arc not working proper and well it dont pierce and makes a mess off the cut I follow cut charts try different thickness of metals speed everything and its just not reliable at all I am at wits end any ideas guys and gals im stumped heres some pics of what I mean pierce wise when it actually does go threw it cutz nice and yes I have the pierce delay set up it still does it on any time given for delay ,ive checked my ground I literaly went over everything help please!!!!!!!!!

[Dustan]

and another pic

[Dustan]

and the air system

[srp]

Dustan - Have you narrowed down the possibility that it might be or not be a problem with the metal? - John

[Dustan]

the metal is good it happens on every and every piece new old rusty bent how do you tell if the metal is no good ???

[Bigrhamr]

What about the pierce height? I assume you are going by the TD charts, but have you measured it to make sure it's right and consistent? If your initial height sensing is mechanical and not ohmic it may be deflecting the metal down before it trips the switch, then when the torch goes up to programmed pierce height the metal springs up and follows it giving you a pierce height that is too low ruining your nozzle. That's one idea..

[srp]

I am only speaking from my own experience. I was encountering a similar situation with 16 ga. HR. The external appearance of the metal looked fine. When I went to cutting galvanized the problem disappeared. I began to suspect something about the HR metal. In the mean time I started cutting my parts from the galvanized which added an additional step in my painting process which I knew I had to do. I was finally able to get galvanealed to eliminate the extra process. I didn't have to go back to the HR. Later on this forum this issue came up again and Jim Colt from Hypertherm related how there could be problems with air plasma systems cutting steel with a high silica content. This problem comes from steel originating from older mills with this old technology. Most steel suppliers are not aware of this problem. I don't know what you have for options on material available. You might try a different type - Laser plate( very flat), Pickled & Oiled, -cold rolled. I think the slag is blowing back on your tip and shorting it out and ruining it. I will add that when I wa having my problems it didn't make any difference how slow I went. Still had the problem. - John

[crowdog]

I've ran into similer cuts with a bad ground. Intermitent grounding problem?

[Dustan]

how did you solve the prob???

[Possumplasma]

Dunstan,
Are you running a digital cut height control ??
From the looks of your cuts, you're either piercing too close and ruining the nozzle or, gaining too much cut height during the cut.
You need to check the pierce height before it starts and if correct, stop the cut part way though and, check the cut height.
Could also be cut speed set too high or, loss of air pressure during the cut.
You really need to check all these things in a methodical way, to indentify the culprit....shouldn't be too hard to find.

Mick.

[elkriverfab]

Dustan,

I have had the same problem at times.
Did all the things you did in order to find the problem.

In the end I tried a different piece of material and found the quality of steel to be crap!
The new piece cut just fine and all I ended up doing was checking, double checking and pulling my hair out trying to figure out the problem with the machine and it turned out to be the steel.

I have purchased brand new sheets to have it cut so bad I had to throw it outside and sit there looking at $70.00 waisted.
The supplier did not care and still do not.

I had to find a different place to buy from.

Some sheets are just so bad to cut specifically from China.
The material from Mexico was better but not constant.

If you see it marked (China) pass it up if possible.
Same thing with tubing and welding on tubing from China.

It would not weld clean at all (spit, popped and sputtered) looked like a five year old trying to weld.

I did the same thing with my welders. Checked settings, checked grounds, checked everything to find out it was the tubing.

It sucks and it is a waist of time and money but it happens.

One thing that helps with welding is not to buy any of that Harbor Freight MIG wire or stick electrodes, it is crap.
I like Hobart rods and Lincoln MIG wire, their rods are OK but have had better luck with Hobart rods.

I look at it this way, if I want it to be a quality weld I don't fill it with crap filler.

As far as the sheet metal it can be hard unless your supplier offers good materials otherwise you don't know what you are getting.

I ended up finding a company that will sell me the US steel and I told them if they slip me Chinese material I will not come back, I waisted too much hard earned money on it in the past.

Several highly detailed projects for customers failed half way through from bad materials (cut quality).

I don't want to start another Chinese bashing but tell your supplier to get you good stuff or just move on.

My 2 cents

[WSS]

Hey Dustan, your pics and description do look like a pierce height issue. OR...are all the holes in your shield clear? I use a torch tip cleaner whenever I see a hard pierce now. I found that to be a pierce problem starter. One indicater of that is it only pierces hard in a certain direction.

Another odd problem I encountered was a nick on a swirl ring that would not let the electrode draw back enough to start the arc properly. I had to use a 10x magnifier to see the culprit. Probably my fault from screwing the group on the torch with gloved hands and did not "feel" it seat properly one time. After the swirl ring was damaged, the problem stayed until it was changed. I actually did not find it until after I put a new one in. By process of elimination, I ended up at the swirl ring. When it was fixed, I went back and looked at it to see why. I had originally thought it was out of round from heat or something. Calipers said it was round enough, so I looked inside with the magnifier and a electrode sliding back and forth. Bingo.

WSS

[jimjimmac]

Dustan,

I'm with Elk River on this one. It's the steel. I had the same problem last week cutting 14 ga. CR with PCam and HT 1000 at 40 amps and 160 ipm. I was cutting a fairly large image, everything cut nice, and then on a long curved area about 8 inches long it didn't cut through, but gouged instead and the sparks flew all over the place. Then, it continued on and finished the remaining 10 inches or so. I backed it up using the speed shuttle dial on the controller, set the amps to about 45 amps, and started the cut again, hoping to blast through. It did a little better and made a wider gouge. But, the image wouldn't drop out because it was still attached. I took the sheet off, used a grinder from the back side and wore down the steel on the back side enough so I could wiggle it back and forth until it broke off.

Having said all that, looking at your pictures, in the first picture, for the square on the left, I see it started nicely, and cut good but then gouged that last section. The square on the right cut all the way through so evidently the settings you were using are correct. In the 2nd picture, when you cut those lines, again the cut was good to start with but then gouged a portion of the cut path. looking at the other lines next to it, the cuts were good.

It's as though the torch raised up, but I think there are 'hard spots' in the steel because if the tip was shot, or the settings wrong, you wouldn't get any good cuts. There's not much you can do. You can't bring the steel back, just try to re-cut the bad areas, grind some from the back side, and hopefully wiggle it back and forth to break it off.

Jim

[Dustan]

Dustan,

I'm with Elk River on this one. It's the steel. I had the same problem last week cutting 14 ga. CR with PCam and HT 1000 at 40 amps and 160 ipm. I was cutting a fairly large image, everything cut nice, and then on a long curved area about 8 inches long it didn't cut through, but gouged instead and the sparks flew all over the place. Then, it continued on and finished the remaining 10 inches or so. I backed it up using the speed shuttle dial on the controller, set the amps to about 45 amps, and started the cut again, hoping to blast through. It did a little better and made a wider gouge. But, the image wouldn't drop out because it was still attached. I took the sheet off, used a grinder from the back side and wore down the steel on the back side enough so I could wiggle it back and forth until it broke off.

Having said all that, looking at your pictures, in the first picture, for the square on the left, I see it started nicely, and cut good but then gouged that last section. The square on the right cut all the way through so evidently the settings you were using are correct. In the 2nd picture, when you cut those lines, again the cut was good to start with but then gouged a portion of the cut path. looking at the other lines next to it, the cuts were good.

It's as though the torch raised up, but I think there are 'hard spots' in the steel because if the tip was shot, or the settings wrong, you wouldn't get any good cuts. There's not much you can do. You can't bring the steel back, just try to re-cut the bad areas, grind some from the back side, and hopefully wiggle it back and forth to break it off.

Jim

yes thats exactly what it is doing the torch just comes down normally and starts a major lift like im talkin blast off way above the material as it is going

[Dustan]

and yes i have digital torch hieght control in case anyone was wondering

[I see spots]

My THC did the same "Blast Off" when I set it up.

I had to switch the pin inputs?? i think.

The THC was trying to lower the torch, but the machine was raising it.



bob

[Dustan]

ya but its a case of it works for a bit then just at random it wants to go up up and away

[Possumplasma]

I'm amazed at how many of you guys over in the States complain about steel quality.
There must be a few second rate mills over there, going by some of the feedback I've heard over the years.
I'm sure there's some real suspect stuff here in Aussie also but, I'm yet to find any.

Mick.

[jimjimmac]

Hey Mick,

It's not the second rate mills that is the problem, its the crappy stuff we recycle that gets thrown into the mix that causes bad steel, like old beat up, can't fix anymore, rust bucket cars and trucks. But you guys down under don't have to worry about that because from what I've seen, you're still driving them.

Jim

[WSS]

Thermal Dynamics may be different than Hypertherm, but with hypertherm, you have to travel clockwise for outside cuts.

WSS

[Bigrhamr]

This may not have anything to do with the problem at hand but I just noticed something odd in the picture. On the completed square cut there is a pile of top slag like you get from a pierce. The odd thing is where it's at, well away from the pierce and on the cut path after the lead in. The one next to it looks like it might be the same but I can't see the whole thing. If I get any slag like that it as always right around the pierce hole. That makes me further suspect either #1 a torch height issue, or #2 a ground issue.
I would do a series of test cuts and randomly during the cut stop and check the torch height with a feeler gauge, piece of shim stock,drill bit or other item of known thickness. If it's off you'll need to change the target voltage, or whatever they call it with your controller. Once you get it cutting at the right height on straight cuts observe it closely to see if it's doing any erratic movements during cutting. If so the next step is to explore the settings that govern THC sensitivity. It can be frustrating but it's not rocket science, if torch and consumables are in good shape and properly sized, path to ground is good and motion control parameters including THC are pretty close you'll get good cuts. Bad steel is a possibility but I wouldn't pin the blame on it until all the usual suspects have been eliminated.

[SignTorch Vector Art]

Thermal Dynamics may be different than Hypertherm, but with hypertherm, you have to travel clockwise for outside cuts.

I think that's standard, that the plasma air swirl spins clockwise, and it leaves a cleaner cut on the inner edge of a clockwise path, similar to how chip removal and edge finish differs on either side of a router bit.

[WSS]

Thermal Dynamics may be different than Hypertherm, but with hypertherm, you have to travel clockwise for outside cuts.

I think that's standard, that the plasma air swirl spins clockwise, and it leaves a cleaner cut on the inner edge of a clockwise path, similar to how chip removal and edge finish differs on either side of a router bit.

Unless he has a southern hemisphere machine. Don't those spin backwards?

WSS

I am joking

Dustan, I believe you have had your machine for sometime. Is this one of those new problems popping up, or has this been an increasing problem?

[Possumplasma]

Hey Mick,

It's not the second rate mills that is the problem, its the crappy stuff we recycle that gets thrown into the mix that causes bad steel, like old beat up, can't fix anymore, rust bucket cars and trucks. But you guys down under don't have to worry about that because from what I've seen, you're still driving them.

Jim

Jeez, here I was, thinking I was doing the right thing driving my '39 Chev all these years.
Of course, the reason it's lasted so long is, we don't salt our roads.....hey, maybe that's whats stuffing up your steel, too much salt...

[WSS]

Mick, the US steel is generally good quality. The US relies way too much on Asian imports. Steel is a big one. Our government makes it tough to compete with countries like China. By the time you have paid and greased all the agencies and inspectors our price is too high. US consumers want cheap products. It hurts the small manufacturer in many ways. It is hard for us to source quality material and even harder to sell the product made with it. I am bellyaching of course and it is not 100% this way to be objective, but I think many feel this way.

WSS