Randomly Not Cutting Completely Through Sheet

[Charlie10]

So I have my cut settings dialed in pretty well and I'm getting good cuts. I can cut say 100 parts and have no problem, but then randomly I will get an edge of one part where the torch doesn't cut all the way through. It shoots a bunch of sparks out the top and leaves what almost looks like a weld seam on the bottom side of the sheet. Then I have to beat or pry the part out (if I can get it out at all) and it will have a very booger-ed up edge and is in general a pain in the ass. Anyone know what would cause that? Using Hypertherm 45 XP.

[motoguy]

What consumables? Finecut?

[WyoGreen]

Without knowing more about your equipment, the 2 general things that come to mind are cut height and air pressure. Either something made your torch rise up a bit, or your air pressure dropped.

Steve

[sphurley]

I have this issue at the slat X points some times.

[jimcolt]

Though you don't mention material thickness and cut settings...I will guess that you are cutting either 14, 12 or 11 ga steel with Finecut consumables. If I am right...here is how to solve the random, non penetration.

1. Inspect the nozzle and shield using the consumable inspection section of your manual as a reference. If orifices are perfectly round, reinstall them in the torch.
2. Verify that air pressure is in auto mode on your power supply, and that you are in cut mode (not gouging / marking mode)
3. Set everything at book specs (pierce height, cut height, cut speed, amperage) except for cut height and arc voltage. Set cut height to .080" (book setting is .060") and increase arc voltage by 5 volts This will raise the real time cut height to .080".

If cutting 14, 12 or 10 gauge with Finecuts you will periodically run into this issue, which I suspect is related to chemical content of the material.....when manganese, silicon and or carbon levels in the material are higher than normal the Fine cut consumables occasionally seem low on power, by raising the cut height the additional arc voltage improves the penetration and will solve your issue.

Don't increase amperage or reduce speed. These both will add heat input that will increase kerf width, will increase dross and warpage.....things that we are trying to avoid with the Finecut consumables. Jim Colt Hypertherm

So I have my cut settings dialed in pretty well and I'm getting good cuts. I can cut say 100 parts and have no problem, but then randomly I will get an edge of one part where the torch doesn't cut all the way through. It shoots a bunch of sparks out the top and leaves what almost looks like a weld seam on the bottom side of the sheet. Then I have to beat or pry the part out (if I can get it out at all) and it will have a very booger-ed up edge and is in general a pain in the ass. Anyone know what would cause that? Using Hypertherm 45 XP.

[Charlie10]

Thank you. I should have specified, Yes I’m using finecut and cutting mostly 16ga and 11ga. Some aluminum as well but have never encountered that problem with it. I have everything at book specs except the speed I did reduce slightly (like 5 IPM I think) to address it and the arc voltages on my table are all way off for some reason. I had to set them all significantly lower or the torch was cutting far too high. I will try bumping it up to the height you suggested Jim and set my speed back to normal. Thanks again.

[Backertg]

jimcolt,

Sorry for the reply to the aged thread referring back to this post you answered in 2018 - I am having very similar random problems under well controlled situations.

Arclight Dynamics 9600 table, Hypertherm 45XP using fine cut consumables, always cutting 14ga mild steel either 1008 cold rolled or 1011 hot rolled pickled and oiled.

sometimes part cut super clean - barely any backside dross and clean topside. With no change in consumables the next cut on the same sheet will have what appears to be low speed backside dross and a few areas that are either rewelded on the backside or not cut all the say through. We are using sheetcam for nesting and the post processor. See the attached photo for tool parameters used. Changing speeds by +/- 3% does not seem to make a difference. Changing consumables does not seem to make a difference.

The table is grounded directly to a earth ground in the foundation. We are running 175psi at the air source capable of 25 CFM at that pressure deliverd to the regulator at the table at 125 psi into the XP - 90psi out. The air is processed thought several coalescing filters, a Hakinson SPX-1 dryer, and a motorguard filter dryer at the table followed by a desiccant drier so moisture should not be a problem. We run with DTHC on.

I know you recommended running at 0.080" torch height rather than the book height of 0.060" which we are spot on. That is the first I've ever heard that recommended. Just want to confirm that is really what we want to try and why technically that is a solution. The non-cut seems to be one issue and the heavy back dross an issue that would say to increase the speed- sort of opposite causes that would dive opposing solutions.

Thoughts appreciated - this inconsistency is driving us nuts....

Thank you!