Plasma Tube Cutter

[stang623]

I'm looking to build a dedicated tube cutting machine however the dilema is plasma versus laser cutting. I really like the idea of plasma and it is much more affordable, therefore I want to figure out how to make it work. Right now we plasma cut some small holes by hand and it results in a lot of stuff inside the tube. I know this is totally different than a programmed feedrate cut on a machine. I'm hoping the machine will help overcome this problem some. My worry is that because of the large kerf in plasma cutting there is a lot of molten metal and it has to go somewhere. Problem is right now when done by hand it goes onto the other side of the tube and is impossible to remove short of sanding it out. This is not acceptable to us though.

I will be cutting 304 stainless mostly and it will range from 18 gauge to 11 gauge or so, roughly schedule 40. Most cuts will be in 16 gauge. Is there anyone out there that does this everyday. Oh yea, diameter is 1.625" up to 3.0". Can I do this with a powermax 45? Anybody capable of cutting samples for me to see the inside of the tube?

Thanks,
AJ

[jimcolt]

If you are looking at laser as a comparison to plasma cutting....you should be looking at a high definition class plasma system as opposed to the air plasma that you are referring to! The Powermax45 is an air plasma that is designed to be a low cost, portable air cutting system. It prodces a wider kerf, slower cut speeds, and uses air as the plasma gas. Comparing laser to air plasma is like comparing a Porsche to a Prius.....they are designed for different needs!

If you looked at high definition plasma (which is still less expensive than a laser, but much more costly than an air plasma) such as Hypertherm's HPR130xd plasma system, you will see that is can use different gas mixtures in order to improve cut quality and metalurgy on different materials. For cutting stainless in the thickness ranges your suggest, the plasma would produce its best cut using F5 (5% hydrogen, 95% nitrogen) as the plasma gas and N2 (nitrogen) as the shield gas. The cutting would be done at low current (45 amps or less) and the kerf width would be as narrow as an air plasma but with much better edge metalurgy and squareness.

A laser would likely use a high pressure nitrogen process.....gas flows would be much higher than the plasma, but would produce a narrower kerf width.

Any of the processes will produce some spatter on the opposing wall of the pipe. Often the spatter in controlled with compressed air flow, a sacrificial back plate, or water flow through the pipe while cutting.

Just remember...there are air plasma cutting systems and there are high definition plasma systems....when comparing to laser it should be high definition!

Here is a link to info on the Hypertherm web site regarding the HPR130xd plasma system.

HPR130XD - HyPerformance Plasma System | Hypertherm

Best regards, Jim Colt

[stang623]

Jim,
Thanks for quick reply. I guess the best way to state my question was I would really like to do a laser but my budget is more of an air plasma budget and because the material is so thin I am hoping that with a dialed in air plasma system I can get a clean edge and minimized spatter on the opposite wall. I've seen your parts and they look really really clean. Do you have anyway to test cut something like this, I could provide the tubing?

Thanks,
AJ

[WSS]

AJ, Try some anti-spatter inside. The dross should be cooled enough by the time it reaches the other side of the tube to make the anti-spatter effective. If that works with hand cutting, it will certainly work with a cnc air plasma cut. To test cheaply, try an aerosol can first before trying the water based stuff in quantity.

WSS

[jimcolt]

AJ,

I understand. You can actually do a fairly decent job with an air plasma using low power and a small nozzle orifice with plasma, assuming te standoff is accurate and the speeds are fast enough. I could do some simple samples for you on my cnc machine....such as slots that run longitudinally on a piece of pipe. I don't have any way to easily do any rotational type cuts on pipe.....and we cannot currently do this in the Hyperthem labs either. There area few companies such as Watts Specialties and Vernon Tool that build special pipe cutting machines. If you want me to do some samples contact me directly. jim.colt@hypertherm.com


Jim

Originally Posted by stang623 Jim, Thanks for quick reply. I guess the best way to state my question was I would really like to do a laser but my budget is more of an air plasma budget and because the material is so thin I am hoping that with a dialed in air plasma system I can get a clean edge and minimized spatter on the opposite wall. I've seen your parts and they look really really clean. Do you have anyway to test cut something like this, I could provide the tubing? Thanks, AJ

[AmericanMetal]

Torchmate makes a rolling system that works with their tables. Not sure if it is adaptable to other though. We have one and it is rather handy. It uses the x-axis to move the torch back and forth along the tube and the y axis is used to tell the machine when to roll the pipe.

[Bigrhamr]

As a low buck solution to the spatter problem I wonder if you could use something like a cardboard shipping tube or even a folded strip of cardboard. Dunk it in water, slip it in the tube and make your cuts. If the spatter made it through the first layer of wet cardboard I doubt it would go across the open air space then through the next layer. Wouldn't cost much to try it.

[stang623]

Guys, all good suggestions and things we can try. Thanks and keep em coming.

Jim, I had sent you an email yesterday and havent heard back, just curious if you got it. It was long winded so if you need more time to respond I can understand. Just checkin.

Thanks,
aj

[tekla019]

Originally Posted by AmericanMetal Torchmate makes a rolling system that works with their tables. Not sure if it is adaptable to other though. We have one and it is rather handy. It uses the x-axis to move the torch back and forth along the tube and the y axis is used to tell the machine when to roll the pipe.

I came across this machine recently: robotic structural steel plasma cutter Seems like it should be able to cut tube - heavy tube/pipe is what my client is interested in. It does HSS. Anyone know if it does round tube ?

[jimcolt]

Best bet is to contact the manufacturer, Burlington Automation. We (Hypertherm) have been working with them for years on a variety of 3 dimensional cutting applications....this one, The PythonX designed for structural steel coping has been a big hit. I believe it can be taught to cope round as well as rectangular tube as well.

Jim Colt

Originally Posted by tekla019 I came across this machine recently: robotic structural steel plasma cutter Seems like it should be able to cut tube - heavy tube/pipe is what my client is interested in. It does HSS. Anyone know if it does round tube ?

[tekla019]

Thanks Jim,
I did that a little while ago and they said it's on their "to do" list. There are folks who do round mechanical tube - Jesse Engineering and others - and these folks who do structural, like the PythonX and now a Voortman machine. DO you you of anyone who has a machine that does structurals and round tube and reads steel detailing files to program the machine ?

[jamiecam]

Jim, dont forget to mention that Multicam has tube cutting options!!