DIY plasma cutter

[Datto-Zed]

Would it be possible to make a bodgy plasma cutter your self using a modified arch welder and a compressor?

I'd imagine you'd want to get your hands on a proper plasma cutter nozzle, then built a hand piece yourself that mounts it all and spaces it from the job.

Sound plausible?

[sv_i]

ahhhhhhhh no

Plasma uses about 20,000 volts of electricity and Liquid Oxy.

it gives a beautiful cut under the right conditions, but on thick metal it will curf (have a slight tilt/edge) on the cut.

At Smorgon Steelmark, I/we cut parts for Caterpillar. the thickest we cut was 32mm Boilerplate and mate, it came out beautiful. The operator was so good we didnt have to grind it or anything. had a mirror finish.

if you want perfect cuts, go get whatever you want cut, Laser cut. Takes a friggen long time, but its perfect, no buckling with the heat (as oxy can do) and you dont have you use water (as with Plasma)

[Datto-Zed]

Hehe.....scrap that idea. :)

Thanks for the info mate.

[TRD-KINGSWOOD]

on the smaller versions of plasma cutters they use compressed air from a workshop compressor.

That sounds like a pretty damn hardcore plasma cutter that your work has sv_i.

[Datto-Zed]

In the demonstration they gave us here at uni, they never mentioned the use of oxy, just compressed air.

They said the one they have here is good for ~8mm max.

I'd only be using this to cut fairly thin metal....maybe 4 or 5 mm max. I'd only need enough power to melt through that sort of thickness. Would a 120A arc welder power supply be capable of that?

[Warpspeed]

I had a bit of a net surf out of curiosity, and all the plasma cutters mentioned used an electric arc + compressed air only. These things cut non ferrous metals as well which is quite interesting. It would make a neat job of 3mm aluminium plate for all sorts of handy little home projects, if you could get it working.

If all it needs is a special nozzle/head, some compressed air and a dc arc, should not be terribly difficult to lash something together for a home project, and a bit of interesting experimenting.

I will be interested to see what others think about this.

[Zed]

Just use the power hacksaw, clunk clunk clunk :)

[80DGY]

If you need to use a plasma, contact me I can sort you out :)

I used one to mod my computer case :D

beer + plasma cutter + computer case = wild ;)

[Datto-Zed]

80DGY: Sweet... I wont be needing it for about 2 months from now. I'll be in touch around then. :)

Warpspeed: I agree it seems that it shouldn't be too difficult. As for the tip, I suppose the only major requirement would be that it's made of something that isn't going to melt as a result of having an arc coming off it.

[Warpspeed]

From what I have been reading, the internal aerodynamic shape of the tip is the real secret as to how these things actually work. Also the tip is regarded as a "disposable" part of the system, along with the electode.

So I reckon you just roll up, and order a spare tip and electode, or even the whole hand held torch gizmo as a spare part, and just build up the compressed air feed and dc arc power supply.

Now if you already had a TIG, I think this might not be all that difficult to do, but who knows ?

It just needs some mad scientist type here on PF to try it out.

[80DGY]

Seriously DZ, I have access to two, both will do a 10mm plate with ease...

[Datto-Zed]

I'll definantly be in touch bout that 80DGY.

Still an interesting idea though.... I might head over to the engineering workshop some time this week and have a closer look that theirs.

[sv_i]

Originally posted by Warpspeed
From what I have been reading, the internal aerodynamic shape of the tip is the real secret as to how these things actually work. Also the tip is regarded as a "disposable" part of the system, along with the electode.

So I reckon you just roll up, and order a spare tip and electode, or even the whole hand held torch gizmo as a spare part, and just build up the compressed air feed and dc arc power supply.

Now if you already had a TIG, I think this might not be all that difficult to do, but who knows ?

It just needs some mad scientist type here on PF to try it out.


er, IIRC proper plasma torch costs a minimum 900 bucks for a cheap one with the good ones running into the thousands.

consumables, that being the electrode, swirl ring and another part range from 12 to 24 dollars each. (for the good hypertherm items. One part uses volcanic rock mined from an extinc volcano in south america IIRC)

at Smorgon Steelmark Metals (now Smorgon Steel Distribution I think) we had a Messer Oxy machine, a Farley Wizard, A Farley Fabricator and a Farley Stiletto

all the machines bar the Fabricator had multiple heads, so if the plate was thin enough and you wanted multiple parts, you could cut two plates side by side.


you can check it out of you go to the Smorgon Steelmark website and check out the plate section. The plasma cutter is the machine giving off the purple coloured smoke.



Warpspeed....its a little bit more detailed than that mate. Dont want to rain on your idea but if you have a look at the machines available on the market, you'll see why they cost a fortune.

[Warpspeed]

Yes, thanks for the information. I just did a quick google search of plasma cutters yesterday, and how they work. The basic idea does not seem too complicated.

I am sure that top end high technology hosts a heap, it usually does. But for home use something a bit more barbaric that can be made to work would be quite acceptable for me.

Just returned from doing a lathe job out in the back shed. My 1,500 dollar home lathe, is pretty stuffed, but with extreme care in setting up, it can still do some pretty precise work, provided there is no hurry.

Looking at new lathes these days, a proper production CNC lathe is easily going to cost far more than the value of my home.

But I am glad to have my old lathe, and would also be glad to own a homemade plasma cutter as well. There is a very big difference between doing quality jobbing on a professional scale, and a DIY weekend project at home.

[sv_i]

true


check out this

http://www.hypertherm.com


remembered the other type of consumable as well

1. electrode
2. Swirl ring
3. nozzle

you need these three parts, plus water, plus gas (I always thought it was liquid Oxy) plus electricity + safety goggles (at least mark 5 tint) to cut.

the water drops the smoke level and cuts the noise. water is actually sprayed around the torch as well, thru a water muffler.

[Warpspeed]

Thanks for that site. I have bookmarked it to study in depth later on, when I have more time available.

When my airflow bench project is completed, I will look into this plasma cutting in a bit more depth, it is very interesting indeed.