Plasma cutting - How thin can they cut?

Another vote for shears if its all straight cuts. Faster,cleaner, straighter and more accurate. Less wastage too as you wont have the loss of the metal that the plasma will “blow away”….
 
Assuming this is a shape not shearable, I think water jet is probably your best bet. No slag, no heat distortion. Next choice would be laser.
 
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.

So the big question: are they CNC “straight”?

I can’t find a small Diacro (24”) or anything that fits on a bench so I’m considering a handheld power shear or nibbled. Are they easy to use with a guide? Do the drops need to be straightened? Im looking to shear a 75x500mm piece. With some accuracy and squareness in mind.


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I have used both hand held power shears and power nibblers. Material cut with the shears had a slight curl....cut with the nibblers stayed straight. material was aluminum and around 20 gauge.
 
So the big question: are they CNC “straight”?

I can’t find a small Diacro (24”) or anything that fits on a bench so I’m considering a handheld power shear or nibbled. Are they easy to use with a guide? Do the drops need to be straightened? Im looking to shear a 75x500mm piece. With some accuracy and squareness in mind.


Sent from my iPhone using Tapatalk
The cuts are as straight as your guide with no cupping. The one negative fault is the nibbling leaves a jagged edge from each nibble made during the cut that if not hidden has to be dressed. In that situation I run my belt sander down the edge dress it. That I believe is caused by the aggressive nature of the 8 ga. nibbler. If when using the nibbler you travel at a slow rate of speed the nibbles are not as pronounced. I do also have a pneumatic Campbell-Hausfeld #PL1519 Pro nibbler with less capacity that leaves a very nice edge on 20-22 ga. sheet metal that needs no dressing at all, narrow cuts do have a tendency to curl though. That would be a far better choice for what you need to cut. I would try Harbor Freight for a cheap one that may fit the bill for a one time only use. Hope that helps some.
 
Plasma arc has a "sweet spot" in thickness when it comes to cutting materials and thicknesses. The faster a material conducts heat, the worse job plasma will do up to the point of being useless. This is largely because the hotter the material, the faster the torch travel must be for satisfactory cutting. When the temperature of the material is in constant flux, it is next to impossible to set a cutting speed that isn't either too fast or too slow. This is not to mention the warpage issue.

Heat travels much faster in sheetmetal than in, say, 11 gauge and above. So much the worse in aluminum sheet. On the other hand, when the material gets over maybe 3/8" thick, the bevel in the cut face becomes a consideration.

My suggestion would be to farm out shape cutting in sheetmetal to a laser cutting service such as sendcutsend. Shear the straight cuts.
 
Plasma arc has a "sweet spot" in thickness when it comes to cutting materials and thicknesses. The faster a material conducts heat, the worse job plasma will do up to the point of being useless. This is largely because the hotter the material, the faster the torch travel must be for satisfactory cutting. When the temperature of the material is in constant flux, it is next to impossible to set a cutting speed that isn't either too fast or too slow. This is not to mention the warpage issue.

Heat travels much faster in sheetmetal than in, say, 11 gauge and above. So much the worse in aluminum sheet. On the other hand, when the material gets over maybe 3/8" thick, the bevel in the cut face becomes a consideration.

My suggestion would be to farm out shape cutting in sheetmetal to a laser cutting service such as sendcutsend. Shear the straight cuts.
Hi, your'e right, I have used some cutters though that cut anything you needed like butter from a 1/4" to 34" thick in one shot with minimum slag. But I do have to admit they were 440v. units. I'm not 100% and may very well be wrong but I think they were Hyper Therm?.
 
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