Plama cutter on copper sheet

Hello all,
I'm considering the purchase of a plasma cutter to cut complex shapes
from copper sheet. Thickness range of interest is 0.020" to 0.125"
(~0.5mm to ~3mm). Most cutting will probably be 1/16" (~1.5mm) and
below.
I've perused the archive and found folks generally in agreement that
this is a reasonable thing to do, but I do have a few specific
questions based on what I read.
1. When cutting copper, how close should I expect the experience to be
to claims that plasma cutters "cut steel like a hot knife through
butter?" Visions of tacking a (non-conductive) template to the sheet
and slicing away are pretty appealing, but does it really work that
way??
2. For cutting copper, how much should I derate the mfr's claims of
capacity? Can I get away with one of the little 110V, internal
compressor models, or do I need more juice?
3. Can I get a clean edge without lots of melty bits...err..I mean
dross on the cut?
It would be great to hear from folks who actually plasma cut copper,
but, of course, any and all advice is greatly appreciated.
Thanks and Regards,
Tom Colson
Reply to
Tom Colson
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Plasma cutters work on copper, but in a different way than on steel. With steel most of the materiel in the cut is vaporized and oxidized into a very fine dust. What slag there is is a brittle edge on the steel that can be broken off easily.
Copper reacts different;y in that it never actually vaporizes, it just liquifies and sprays all over the area below the sheet. Think of it as aerosol liquid copper.
Also you will have to cut very slowly on heavier copper like 1/8", to make sure you cut all the way through.
Copper takes twice the power of steel to weld or cut. So a machine that can cut 3/8" steel can just handle 3/16" copper, but for any kind of production work I would actuall derate it by 2/3. So for a lot of cutting on 1/8" sheet I would get at least a 3/8" machine, but the bigger the better.
It will leave a burr on the edge that is quite dramatic, but can be easily removed with a sanding wheel on a grinder.
I do it all the times since I am one of the few guys in Seattle who is willing to make curved copper wall caps. I just made a HUGE copper bar top for a bar in downtown Seattle. Plasma cutters do work, and in many ways are the best solution for copper.
Reply to
Ernie Leimkuhler
Forget all that knife through butter buuuuullshit. Plasma cutting isn't all that great. First of all, get a machine rated for at least 2X what you actually what to use it on. It's dirty, noisy, slow, and it smells bad........ also, you probably don't have the humungus amounts of electricity in your shop to cut what you want to......... even if you're willing to initially spring for 2 to 3 grand, for a good one. It's not an artist's pencil....... sorry about that.
Reply to
larsen-tools
Thanks for the info!
I must admit I'm a bit mystfied as to how to reconcile your comments with Ernie L.'s comments. Or maybe
is as good as it gets for a copper cutting process?
Regards,
Tom
Reply to
Tom Colson
Ernie,
Thanks for the detailed comments. If you wouldn't mind, would you match your experience against the comments of 'larsen-tech' re:
Your bar top project sounds pretty cool. Have you put pix up anywhere yet? What thickness copper was it made from?
You mentioned that
What other tech's did you consider to select plasma as "best"?
Thanks again,
Tom
Reply to
Tom Colson
My experience cutting complex patterns in 1/16" copper is that if the speed is correct, there is not much to remove from the back. Using a properly set up CNC plasma cutter, the only time I get a buildup is when the machine slows for turns. And most of that buildup can be knocked off with a finger nail. But it may be near impossible to get this kind of result with a hand held torch.
You definitely need a lot more power than for steel. The machine I use has a Hypertherm Powermax 900. It was severely challenged just severing 1/4" copper plate.
Reply to
Footy
Well it is dirty since it sprays molten copper out the backside,and it produces enough dust to require decent ventilation. I don't think either of these is out of line. As to Noisy, I think he is refering to the older HUGE CNC plasma tables that sounded like a 747 landing in your closet. The newer hand held ones are quite civilized. Smell is subjective. I prefer to wear a respirator when plasma cutting to reduce the amount of fine metal dust I breathe.
Once agin I think he is refering to he large CNC plasma tables. I have a Thermal Dynamics Pak38XL and it only pulls 15 amps on 110 volt or 10 amps on 220 volt
$2000 will buy you a Hypertherm Powermax 1100 for cutting 1" steel
My Pak38XL costs around $1000
Not yet. I will update my gallery soon and add them.
16 ga. , which is very thick, but the 24 ga we used 6 years ago was shredded really fast so we went really heavy this time.
Router with carbide bit and wooden trace patterns, jigsaw, bandsaw, power shear, power nibbler, circular saw with non-ferrous blade, thin abrasive wheel on rt angle grinder. I have tried them all.
1/4" masonite makes the best trace patterns for plasma cutting and when combined with a steady hand, you can get good results.
Reply to
Ernie Leimkuhler
Dirty, noisy, slow, and it smells bad ........ those are ALL subjective terms. Humongous amounts of electricity......... that's relative.
One's perception depends on if you have an industrial shop (Ernie's case) or, if you are doing this around the house (my case).
A year ago I bought a Thermal Dynamics cutmaster 75 w/ a hand torch from AirGas........ more machine than I ever thought I'd need..... for $2300. It's fast on the light stuff - slow on 1/2" steel, which is what I wanted it for.
Then, I ran a branch to a new sub-panel to get 220v, 60 amps. ($1500)
I already had a 220v, 15 amp, compressor big enough to keep up with the cutter, so I spent another $110 for a special T-D drying filter.
I never have been able to coordinate the power and speed, so that the bottom slag just kind of flakes off...... I do a lot of grinding. (I already had a couple of grinders)
I do most of my cutting over a 55 gal drum because the driveway was turning brown.
To fine tune my original opinion let me say ...... Plasma cutting is HOT, dirty, noisy, slow, smells bad and it's expensive. Is it fun?????........ sometimes YES.
Your results may differ :-)
Reply to
larsen-tools

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