Plasma cutting - How thin can they cut?

[Charles scozzari]

https://bugo.com/track-cutting/ thin stuff is like 110 inch cut in one minute

Nice

 

[Headhunter Pipe Co]

I'm trying to find concise, clear information on how thin a plasma cutter can cut. Specifically, mild steel, 20-24 ga. Anybody do this reliably?

More specifically, has anyone done this on a CNC plasma cutter? Is it possible?

I'm looking for clean, straight cuts, a quick removal of any minimal slag and then the parts go straight into a forming operation. Does this sound reasonable?

cut the 10 ga cutting time by half or double the travel
20 ga steel should be 350 ipm minimum

​

	inches	mm	amps​	ipm​	mm/min​
Material	Thickness	Current	Maximum cut speed*
Mild Steel	10 GA 1/4 3/8 1/2 3/4 1	3 6 10 12 19 25​	45 45 45 45 45 45​	175 75 40 25 10 5​	4445 1905 1016 635 254 127​
Stainless Steel	10 GA 1/4 3/8 1/2 3/4	3 6 10 12 19​	45 45 45 45 45​	150 55 32 18 9​	3810 1397 813 457 229​
Aluminum	10 GA 1/4 3/8 1/2 3/4	3 6 10 12 19​	45 45 45 45 45​	280 100 42 25 10​	7112 2540 1067 635 254​

* Maximum cut speeds are the results of Hypertherm’s laboratory testing.
F

 

[Flynth]

I have a Black and Decker 8 ga. nibbler and use that in lieu of my plasma cutter on 20 ga. with no distortion. Work well for me, from circles to straight cuts.

I too use a nibbler for cutting thin gauge steel since I bought it. Before I used plasma and the edge was OK from 6ft away. However, the thread poster wants it Cnc cut, so a nibbler is a no go.

As per the table posted above, you need fast travel rates to get good edge quality in thin gauge materials.

As others said. If its not shear'able a laser is going to be quite cost effective and it will look good too.

 

[AGCB97]

How about a rotary shear like this?

https://www.amazon.com/Woodward-Fab-Throatless-Rotary-Shear-WFMS/dp/B0012GMKUY

I have a very old one that I motorized. Cuts great!

 

[denny98501]

All helpful replies...thanks guys. If anyone thinks of any other advice or thoughts it is much appreciated.

I'm really on the fence between shear or CNC plasma.

They really are different machines for different uses. I have a 30 inch Pexto shear and it works fine for making straight cuts in 24 ga or less metal that is less than 30 inches wide. Shears are the industry standard for blanking SM for later bending. No burr real clean cuts. No messing around. Put the metal into the shear and stomp. It is done.
I also have a Langmuir CNC plasma with 45 amp Razorweld plasma cutter. It works wonderfully well. I mostly cut 1/4 inch hardened steel. but also cut 1/16th inch stainless, titanium and sheet metal. There is fair amount of messing around. You first need a dxf drawing. then you need to post process the dxf into a cutting file with a program such as SheetCam (SheetCam is an excellent program). You have to select all your cutting parameters such as speeds and amperage. The post processor file goes to the computer running the plasma cutter. Put your metal on the table, turn on the air compressor, the plasma cutter, maybe the air dryer and press the start button. Its impressive. Sparks and water splashing from the water table below, the sound of the compressed air. Your part will be cut out of 1/4 inch steel at about 30 inches per minute. If you entered all of the parameters correctly, the edges will be smooth and your friends will be impressed. Rounded cuts, internal cuts, artwork, fittings and holes are effortless. Usually.
If you are buying a plasma cutter, get a water table. Plasma cutting makes a lot of smoke and dust. The water table absorbs almost all of it. The water splashing on the bottom of the metal keeps it cool so it doesn't warp. Thin metal will warp without water. Also order the torch height controller. the torch will then follow the warp of whatever you cut that may be warped. Hard to cut warped metal without a THC,
Figure 15 to 30 minutes start to finish for anything you cut. Add in another few minutes for cleaning up water that may have splashed out.
Plasma cut steel becomes hard like carbide on the cut edges. You cannot drill a hole larger. It welds fine.

Plan on spending about $5000 for the plasma table and controller, 10 cfm air compressor, air dryer, a 5 gallon bucket of rust preventative and a set of annular cutters for the holes that you need to be perfect because the plasma won't quite do it without some trial and error.
You will make many new friends that need art and home projects cut in 1/16 inch to 1/2 inch steel.

 

[AGCB97]

A throatless rotary shear.

 

[Tmate]

Agree with denny98501, there are easier ways to cut straight lines and with a finger brake you can form duct fittings and other simple shapes. Complex shapes and metal art are another matter.

Unlike denny, I have a small (2' x 2') table which I use outdoors to eliminate the plasma smoke and dust issue. I keep it under my deck protected by a fire pit cover. Only the motors are on the table, and I take 5 minutes to connect the wires and install the torch. The computer, compressor, and plasma cutter are just inside my basement door.

I don't cut anything thinner than 11 gauge (1/8"), and warpage has never been a problem for me. If the steel has some warpage to begin with, as it usually does, I clamp it down in a couple of places to straighten it out while cutting. I have a torch height control, but I do better without it on my small table, and took it off.

 

[vtcnc]

Agree with denny98501, there are easier ways to cut straight lines and with a finger brake you can form duct fittings and other simple shapes. Complex shapes and metal art are another matter.

Unlike denny, I have a small (2' x 2') table which I use outdoors to eliminate the plasma smoke and dust issue. I keep it under my deck protected by a fire pit cover. Only the motors are on the table, and I take 5 minutes to connect the wires and install the torch. The computer, compressor, and plasma cutter are just inside my basement door.

I don't cut anything thinner than 11 gauge (1/8"), and warpage has never been a problem for me. If the steel has some warpage to begin with, as it usually does, I clamp it down in a couple of places to straighten it out while cutting. I have a torch height control, but I do better without it on my small table, and took it off.

I'm building the JDGarage plasma cutter table. Do you have any starting recommendations for 22ga.? I read 350ipm above, sound right to you?

 

[vtcnc]

Agree with denny98501, there are easier ways to cut straight lines and with a finger brake you can form duct fittings and other simple shapes. Complex shapes and metal art are another matter.

Unlike denny, I have a small (2' x 2') table which I use outdoors to eliminate the plasma smoke and dust issue. I keep it under my deck protected by a fire pit cover. Only the motors are on the table, and I take 5 minutes to connect the wires and install the torch. The computer, compressor, and plasma cutter are just inside my basement door.

I don't cut anything thinner than 11 gauge (1/8"), and warpage has never been a problem for me. If the steel has some warpage to begin with, as it usually does, I clamp it down in a couple of places to straighten it out while cutting. I have a torch height control, but I do better without it on my small table, and took it off.

Nice work!

 

[DavidR8]

I'm building the JDGarage plasma cutter table. Do you have any starting recommendations for 22ga.? I read 350ipm above, sound right to you?

I’m interested to see how your build progresses. I’ve been eyeing the JD setup as well.