HELP AGAIN!! Won't cut all the way through

[evoandyvii]

So cutting large metals and wasting a lot of materials, consumables, time, and money.

I have: a thermal dynamic cutmaster 152 set up to a water table.

problem: The machine will pierce and cut completely through the metal, but in random spots it will not compeletly cut all the way through the metal. I'm force to use a hammer and punch and smash the peaces out... This plasma cutting thing is driving me crazy

I've got the pierce delay, cut height, Pierce height, and cut speed all figured out. Just recently upgraded all the air lines and even slapped on a big boy filter. Solved some of my beveling issues but there is still some.

If anyone has any input I'd love to hear it because I'm not to far from shooting the machine lol please help.

[ronsii]

When you say random spots... make sure you have a good ground to the material being cut, not just material sitting on slats that are grounded...ground clamp actually attached to cut material.

[elkriverfab]

Check for dry air to plasma cutter.
Must be dry, dry, dry.

Check all grounds, I ground direct to work piece every time.

Make sure your consumables are correct for torch ( probably are but it doesn't hurt to double check, I have had the supply shop give me the wrong ones in the correct packaging on several occasions).

Also check to make sure you are not getting sold crap steel.

I too was cutting yesterday and had to pull a half cut piece of older scrap to finish the job and it was a poor quality piece of sheet steel (China)....

Cut bad, sloppy and not all the way through.
I put a better piece of steel on and it went back to cutting great again.

I cant stress enough on steel quality, I have wasted a lot of time and money on steel that was crap.
Nothing like spending $100.00 on a sheet and have to pull it off the table and throw it out because you cant cut it with clean results!

[jimcolt]

Moisture in the air comes through in slugs.....at random times. The torch is designed to cut with air....which is 20% oxygen and 80% nitrogen.......when moisture is added this mix changes, which affects the arc....which will show as loss of power in the cut. This is the time of year that we most often hear of these symptoms.

The only sure cure for moisture in the air is a properly designed rifrigerated dryer or dessicant dryer system. Either of these that does not also have an automatic drain after the air is cooled, or after the dessicant tank.....as well as an automatic compressor drain may be suspect. Filters generally cannot handle the moisture as they get saturated and pass water through.

Jim Colt Hypertherm

[jimjimmac]

Jim Colt,

This was my experience not cutting all the way through. Tell me if it is possible. I was cutting multiple images out of 10 ga. about 5 inches wide and 14 inches tall. Lots of detail. It had 38 pierces inside, then the outer cut, the last cut. Every so often, on the outer cut it would only gouge for an inch or so, then cut good. Sometimes this would happen 2 or 3 times on one image. I could see the sparks fly on top and the sound would change. I'd stop it, back it up, bump up the amps, lower the speed and cut the spot again. Once, only after moving the carriage, did I notice that there were many, many places where the molten steel from the pierces were all over the top of the steel, sometimes in the exact path of the outside cut. I think you know where I am going with this.

I wondered if the tip, cutting at 1/16 of an inch, traveling at 90 IPM right over one of these pierce splatters, which for a split second indicated to the height control that it was too close causing the tip to rise, not cutting all the way through for an inch or so, then realizing that it was now a little too high and then drop back down to 1/16 inch and continue with a good cut.

After seeing that, I used a piece of metal to scrape the pierce slag loose after cutting the inside detail, then blew it off with the air hose, and then cut the final outside path. Bingo.....it never again gouged and always cut through. With 10 gauge I could just as well have turned DHC off for that matter. This might be a question for George, but does DHC react that fast and could the splattered slag have cause what I described? I have a P/Cam with air out of an air dryer and an additional in-line cannister with the fiber toilet paper type filter in place just before the HT1000.

Thanks,

Jim

[evoandyvii]

Check for dry air to plasma cutter.
Must be dry, dry, dry.

Check all grounds, I ground direct to work piece every time.

Make sure your consumables are correct for torch ( probably are but it doesn't hurt to double check, I have had the supply shop give me the wrong ones in the correct packaging on several occasions).

I cant stress enough on steel quality, I have wasted a lot of time and money on steel that was crap.
Nothing like spending $100.00 on a sheet and have to pull it off the table and throw it out because you cant cut it with clean results!

I'll talk to my boss about figuring out a cheap air cooler or "dryer" for the table. I have herd of people using buckets of ice water coiling the air hose and dumping them. Has anyone tried this??

The ground seems in a good place but I'll check the grounding point again just to be sure.

And steel quality, I've read a lot of threads on steel quality I have done some welding before and I've seen what shitty metal can do to a weld. So i'll also dig into where the metal for my table is coming from.

ground clamp actually attached to cut material.

I"ll try this but i have a water table so i don't wanna submerge the grounding clamp but i guess it never hurts to try once.

when moisture is added this mix changes, which affects the arc....which will show as loss of power in the cut. This is the time of year that we most often hear of these symptoms.

True I've been doing a bit of searching and have found a lot of people saying moist air and such. My current set up is Compressor tank > splitter > filter > plasma cutter. And I live in Houston, TX sooo hot humid air is pretty much everywhere LOL.

THANK YOU THANK YOU THANK YOU EVERYONE!!! all you guys have helped a ton I was really moments away from tossing this thing but this gives me new hope. I really appreciate all your guys help and the information this forum provides thanks a ton.

[weldguy]

If you are noticing that the "random" spots are in arcs or direction changes then you may want to try slowing your cut speed down just a little more.

It does however sound like moisture is going to be your issue after reading your setup and shop location.

MOISTURE IS OUR ENEMY

[rock4xfab]

Could be moisture but if he is not grounded directly on the material, that can cause and issue. I to have a water table but I still ground to the part.

[Metal Lee]

I agree< I always ground the part as well, seem to work better when your table gets built up with dross. the other thing you can do is increase your peirce time a little, if your metal is dirity or has a thick millscale this will allow for penetration.