Plasma torch issue.

[plinker]

I have this machine, Matco MA48, has a Nu-tec NPT48 torch, uses S45 consumables.
https://www.matcotools.com/catalog/product/MA48/40A-PLASMA-CUT-1-2-110-240V/


I've got a couple hours on it, worked well until today. I was cutting thin aluminum diamond plate (1-1/16), first cut, about 9" went fine, second cut the arc went through the side of the shield cup/nozzle retainer. So I took it apart and fount it had a hole melted through it and the swirl ring partly melted/burnt.

The air pressure was ok, all consumables tight and not worn ( I was going to replace the nozzle afterwards). Not sure if the torch body is damaged from the arc or not, see pics. I think I can replace the cup & swirl ring and be ok, just trying to figure out what happened.

 

[dtnel]

I have this machine, Matco MA48, has a Nu-tec NPT48 torch, uses S45 consumables.
https://www.matcotools.com/catalog/product/MA48/40A-PLASMA-CUT-1-2-110-240V/


I've got a couple hours on it, worked well until today. I was cutting thin aluminum diamond plate (1-1/16),

You mention 1-1/16 or was it 1/16 thick plating? If you did the larger than 1 in as described in your post that may me part of the problem as it may be to thick. It shows 1/2 in thickness on the product page for the thickness it can cut.

I'd maybe check with your local dealer and play dumb and if you're a good enough customer he should take care of it for you. IF my snap on dealer wouldn't cover something on a new machine I'd be looking for a new tool guy regardless of how much I owe him and he'd know once the bill was paid we'd be parting ways for good. Good luck and lean on the tool guy good. If it's in warranty they should be able to cover it.

Sent from my SM-G955U using Tapatalk

 

[plinker]

"duh" moment on my part, it was 1/16". It's under warranty yet (bought last oct. IIRC), so I was going to check with him next time I see him.

 

[Jbullfrog]

Did you touch the piece you were cutting with the torch while it was energized?

 

[plinker]

I dont think so but it's possible. I was starting a second (drag)cut when it happened, wasn't doing anything any different then I have before using this machine or the Thermal dynamics machine where I used to work.

 

[MoonRise]

I
The air pressure was ok, all consumables tight and not worn ...

Umm, those consumables ARE worn out.

At the least the tip was worn out. (it was good of you to post the picture showing both the used and worn out tip and the brand new tip for comparison).

Some possible causes of your torch damage:

- 'snuffing' the arc by jamming the torch tip against the workpiece. The plasma arc will still try to go somewhere, which could be sideways through the conductive torch parts.

- related to 'snuffing' the arc, you then have no cooling air flow through the torch and a 10,000+ F plasma inside the torch

- if you don't have CLEAN and DRY air going to the plasma cutter, consumables wear out much faster and you may suffer parts damage.

An article from a Hypertherm application manager about the importance of using clean dry air when using a plasma cuter:

https://www.achrnews.com/blogs/16-g...ean-dry-compressed-air-for-air-plasma-cutting

My non expert opinion of the damage? Look at your Picture #4 and see the black marks on the swirl ring(?), which could be an indicator of moisture getting in there and interrupting the normal air and plasma flow and also giving the plasma a different conductive path (through the torch guts) and blowing out the side of the torch.

If you really want to get some experts' opinion, try calling one of the plasma experts. Maybe Hypertherm?

 

[plinker]

Figure I'd update this,

I replaced the consumables, swirl ring & cup and it works fine. I'm going to agree the consumables were worn, I just didnt realize it based on I'm the only one using it.

The air should be dry, but I'm going to add a desiccant filter of sorts as well I think. It currently has two, the OE one, plus a Snap-on branded Sharpe unit.

 

[The Cobbler]

I just recently learned of drag tips ( Thanks to GJ) and those don't look like drag tips to me

 

[The Cobbler]

here are the drag tips I purchased https://www.ebay.com/itm/221793311448 see the tip is different

the tips you have are meant for an air space

 

[ovrrdrive]

I agree, those aren't like any drag tips I've ever seen. I wonder if it being against the plate made it fire back into the torch and blow up like that.

 

[JPinSTL]

That is either a real Trafimet S45 torch, or a Chinese copy. They are a decent blow back style torch, not a HyperTherm, but a decent torch. I had a Harbor Freight 95136 Plasma Cutter for 10+yrs and cut miles of steel with it and the Trafimet S45 torch.

The tips you have shown are "pipe" tips. Great for detail work, angles, and even a little gouging. These are also available in different amperage ratings, basically the kerf size changes, but the .9mm size seems the most common. You do need to hold them off the work if you want them to last. Ebay is full of roller guides that will fit that torch and is worth it for cutting straight lines, etc.

The "drag" tips are handy to have too, just harder to see what you are cutting.

Real Italian Trafimet consumables (copper tips) seem to last longer, but are harder to find, and cost double. The Chinese copies are cheap enough but you run through them fast. The silver electrodes seem to last the same regardless of origin.

Dry air is important for any plasma cutter. A slug of moisture, guarantees blowing up a set of tips.