1/4" AR500 Pierce Slag Causing Torch Breaks

[ME Newb]

I've cut 5 sheets of 5x10 AR500 with only a few torch breaks from pierce slag(that's over 5,500 pierces) now since yesterday it's been struggling with the pierce slag and causing way too many issues. It started with 3/8" AR500 and continued over to the 1/4". What could be causing this? The only thing that I can come up with that is different is this rainy weather but I wouldn't think that could cause this issue?? I have a refrigerated air dryer. I put in a new nozzle and shield but I didn't change the electrode since it looked ok. .15" pierce height,.5 second delay at 65 amp on a PM85 unit. JD Squared table. Pic attached

[ME Newb]

[ME Newb]

I put a whole new set of consumables in including the swirl ring and retaining cap and it is piercing much better. Still don't know what was causing it

[larrycameron44]

When you say “Torch Breaks”from slag what exactly do you mean?

Larry Cameron
RusticMetalArt

[jimcolt]

if you are talking about "Pierce Slag Piles" that form on the top of some materials (thicker AR and Stainless usually)....then the torch collides with this pile at the end of the cut, then here are some solutions:

- Longer lead in (depending on your part geometry) so that the end of cut does not get near the slag pile.
- spray mig welding anti spatter on the top surface...this often causes the pierce slag pile to break away or blow away from the force of the shield air flow.

Jim Colt Hypertherm

[Simko]

- spray mig welding anti spatter on the top surface...this often causes the pierce slag pile to break away or blow away from the force of the shield air flow.

This!

I started using mig spatter spray on everything. On 3/8" cuts, I used to have to chase the torch around with a putty knife to chip the pierce slag pile off before it came around to the end of the cut. Now with the mig spray, there is zero slag around the pierce.

It works so good, I considered spraying the bottom of the sheet to see if it helps with dross.

[ME Newb]

Great ideas guys. Unfortunately with my part it's cutting a 1/4" hole in 1/4" steel and then the torch passes by within 1/4" or less of that hole. I'll pick up some mig splatter stuff and see how it does. Thanks

For what it's worth it ran a whole sheet flawlessly yesterday when it was nice and sunny and low humidity and it's doing great today with the same weather conditions.

[jimcolt]

Another technique is to do all of the piercing first then stop and knock off any slag piles and continue cutting with edge starting on the pierce holes. I have done this a number of times on thicker materials. Jim Colt Hypertherm

[motoguy]

Another technique is to do all of the piercing first then stop and knock off any slag piles and continue cutting with edge starting on the pierce holes. I have done this a number of times on thicker materials. Jim Colt Hypertherm

This has worked amazingly well for me.

[jason.jason.p]

Another technique is to do all of the piercing first then stop and knock off any slag piles and continue cutting with edge starting on the pierce holes. I have done this a number of times on thicker materials. Jim Colt Hypertherm

This has worked amazingly well for me.

On really thick stuff like 1.25" A26 I will manually turn the torch off in Mach3 right after it fires so I have a small divot at the pierce point then I will drill a 3/16" through hole with the cordless drill and edge start settings from there. If I let the torch linger too long before turning it off I may have to anneal it with the cutting torch before drilling since the plasma torch hardens the top layer.

Trying to pierce something that thick with the plasma will ruin consumables with one pierce.

[tnbndr]

Another technique is to do all of the piercing first then stop and knock off any slag piles and continue cutting with edge starting on the pierce holes. I have done this a number of times on thicker materials. Jim Colt Hypertherm

Is there a setting in SheetCam that codes all the pierces first? Otherwise how is this accomplished?

[motoguy]

Another technique is to do all of the piercing first then stop and knock off any slag piles and continue cutting with edge starting on the pierce holes. I have done this a number of times on thicker materials. Jim Colt Hypertherm

Is there a setting in SheetCam that codes all the pierces first? Otherwise how is this accomplished?

For CandCNC/Mach3/Windows setups, yes there is. It's a custom post Les (Sheetcam creator) wrote. It's in the Sheetcam forum, here:

https://forum.sheetcam.com/viewtopic.php?f=4&t=7059

One for CandCNC/CommandCNC/Linux is being worked on. You can see the discussion of it further down on the linked page.