Cutting 3/8" plate.....issues...

[Eggman]

Currently I have been trying to cut various sized holes in some 3/8" HR steel plate. The holes are coming out slanted.

Running Plasmacam, Hypertherm 65, 65 amp consumables, good ground, dry air, machine set at 45 ipm and 65 amps.

[weldor2005]

You will be waiting for Jim's reply to answer this for you,

Other than that I can say that angularity is related to having proper distance from shield to material. to close and you might get a negative drift, to much and a positive drift. did I get that right Jim? <--Just curious if I learned anytihng from reading your posts..

You will however not get a straight cut, but shouldn't have that much drift.

[plain ol Bill]

Cut your speed by at least 1/3 and try again. They should be much better. What is your pierce and cut height?

[planetxfred]

First check your consumables, make sure ALL the tiny air holes are clean in all the parts. A blocked hole in the shield will push the plasma beam to one side. Are you cutting at the OPTIMUM speed listed in the chart?
Make sure the nozzle is new, the hole needs to be perfectly round & the right size.
Fred

[mdwalker]

1. Be sure you have new or undamaged consumables. You can't make a good cut with bad consumables.

2. Go by the cut charts for optimal speed and torch to material height.

3. When cutting holes set your speed to 60% of optimal speed.

4. Be sure your height control maintains the torch at correct height.

5. Be sure the nozzle is clean. If you get spatter built up on it it will affect your cut height.

6. Be sure your pierce delay is set to the proper delay to allow a complete pierce before cutting.

I'm sure Jim can add to this but this should help you start troubleshooting.

Danny

[jimcolt]

mdwalker has it covered. Holes should be cut at 60%.....the pierce height must be correct, the torch must index to cut height as soon as the pierce is complete. Program a lead in that is long enough so the torch has time to index down from pierce height to cut height before getting into the hole radius. I prefer no lead out.

The pictures show a lot of taper....indicating that the torch is too high and the cut speed may be too high as well.

Here are holes cut with my Powermax85 on 1/4" and 3/8" using these techniques.

Jim Colt

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IMG_2637.jpg (43.07 KiB) Viewed 3812 times

[Stout]

Here are holes cut with my Powermax85 on 1/4" and 3/8" using these techniques.

Jim Colt

That must be the new Duramax torch in the picture?

[jimcolt]

The picture with the torch is of a Powermax45 torch, not the Duramax. That piece is 1/4" cut with the 45 amp shielded consumables. The Duramax 45 amp process (cut quality, speed, etc.) is the same as the Powermax45 torch.

Jim Colt

Here are holes cut with my Powermax85 on 1/4" and 3/8" using these techniques.

Jim Colt

That must be the new Duramax torch in the picture?

[beefy]

Hi Jim,

I'd love to know your opinion on this suggestion, which comes from a company here in Australia called ART (Advanced Robotic Technology - sounds high tech for plasma tables ).

Cutting too high causes bevel with the cut width more at the top and less at the bottom. Cutting too low causes the opposite. For hole cutting ART recommended using this to advantage in cutting holes, and having the cutting height lower than normal to counteract the bevel.

I'm guessing there is a downside to that otherwise all cuts could be done at a lower height until there was zero bevel.

Cheers,

Keith.

[jimcolt]

Most plasma torches cut best at a height of about .060"off the plate. You really cannot get much closer than that without the risk of collision....and there is no need to. Look at my hole pictures on my previous post.....they have a very minimal taper. It is correct that higher height causes more taper, higher speed (when cutting holes) creates more taper as well.....so getting the height correct (torch manufacturers specs) and running at 60% of the normal contour cutting speed is the best solution.

Hypertherm has some high end high definition plasma systems that (coupled with the corect cnc control, height control, cnc machine and CAM software) can cut holes with no taper.


Jim Colt

Hi Jim,

I'd love to know your opinion on this suggestion, which comes from a company here in Australia called ART (Advanced Robotic Technology - sounds high tech for plasma tables ).

Cutting too high causes bevel with the cut width more at the top and less at the bottom. Cutting too low causes the opposite. For hole cutting ART recommended using this to advantage in cutting holes, and having the cutting height lower than normal to counteract the bevel.

I'm guessing there is a downside to that otherwise all cuts could be done at a lower height until there was zero bevel.

Cheers,

Keith.

[beefy]

Thanks Jim.

[Eggman]

Sorry I wasn't able to get back here sooner. My day job keeps getting in the way. Thanks for the suggestion, I will be trying them out either tonight or tomorrow. Will let you know what I find.

[Eggman]

WOW!! what a difference it made. Dropped the IPM to 27 from 45, pierce was at 0.8 and distance off material was around 0.060. I am still getting a bit of slant on the cuts, but its way better than before. I currently have #6 wire from the main box in the house to the garage box which is about 50 feet. Then I come out of the garage box to the Hypertherm 65 with about 12 feet of #8 wire. Would the #8 wire be causing some issues with the cut quality by dropping the volts more than it should be?

Thanks again for eveyone's help.

Eggman

[jimcolt]

The Powermax65 will auto compensate for low input voltage.....it will operate on any voltage from 200 to 600 volts.....with no change to cut quality.

These air plasma systems will always produce a bit of taper.....more so on aluminum than steel.

Jim Colt Hypertherm

WOW!! what a difference it made. Dropped the IPM to 27 from 45, pierce was at 0.8 and distance off material was around 0.060. I am still getting a bit of slant on the cuts, but its way better than before. I currently have #6 wire from the main box in the house to the garage box which is about 50 feet. Then I come out of the garage box to the Hypertherm 65 with about 12 feet of #8 wire. Would the #8 wire be causing some issues with the cut quality by dropping the volts more than it should be?

Thanks again for eveyone's help.

Eggman