Can my tig be used as a Plasma?

[Rick]

Hi,

I've had an idea for a while to try to make a plasma...

basically it's a transformer to give a voltage (about 30V?) and a current (about 40 - 50A?) through a TIG type of electrode and a compressor to squirt some air (about 80 PSI?) and blow the melted metal away...

Can't be that hard, surely?

OK there'd probably be some extra components to make it safer and to stop interference, etc, but it should be do-able with a bit of thought.

Could anyone comment on the volt/amps/psi?

Any other thoughts or ideas gratefully received...

Regards
Peter

This is basically what i planned to do.

By a plasma torch and user the power from my tig /airline to try and make it cut.

 

[mishka]

Plasma cutters typically operate at an OCV of around 300 volts, dropping to around 90V during the cut. A TIG, on the other hand, has typical OCV around 40V, dropping to around 12V during welding.

I'm not saying its impossible, but I think the lower operating voltages of a TIG welder won't be able to maintain an arc for the plasma.

 

[peterd51]

Hi,

ouch, that's high!

Is that 300 V AC or DC OCV?

But surely at that sort of volatge and current the workpiece would be lethal if you toched it with a bare hand?

Still, the guys that make them can do it safely...

it should be possible as a DIY project.

Thanks for the input.

Regards
Peter

 

[shenion]

It is DC.

I have gotten 300V DC shock before. It is not usually lethal. However the effect can be deadly. TV repairmen working on those old console TV's would break their neck when leaning inside the cabinet to look at something. The shock caused them to stand up violently.

In my case, the soldering gun in my hand hit the back wall of the room as my arm contracted suddenly.

There is a DIY project on the net somewhere. Mains AC rectified and fed to the torch through a inductor and a HF spark generator. No isolation from the mains and no current control. Not safe by any means.

 

[peterd51]

Hi,

it's a starting point, thanks.

How about using an old Arc set as a basis?

I sold one on ebay earlier this year as I found it too difficult to use but there are a few on the car-boots for £20 - £30...

I'd be interested in seeing what happened if I melted some steel and tried to blow it away with a compressor...

I've melted through thin MS plate with my MIG set often enough and it simply dripped on the floor!

Regards
Peter

 

[Drains]

I'd be interested in seeing what happened if I melted some steel and tried to blow it away with a compressor...

Do you mean this?

I suggest exploring the rest of the knowledge section of that site, for useful info...

 

[peterd51]

Hi,

not quite what I had in mind as that's cutting grooves in thick plate...

I'd noted over the years that if I set my MIG current too high on the thin plate that I usually work with it didn't just blow though, it would 'cut' (although the edges were more than a bit ragged!) as the weld pool dropped under gravity.

Thanks for the site link though, I'll do some more research there.

Meanwhile I found a guy on another site who's apparently an Electrical Engineer and he's designed and built his own Plasma Cutter. Details are on his web-site:

http://www.jblankenagel.net/plasma cutter construction.pdf

Also there's some discussion over several pages on :

http://www.weldingweb.com/showthread.php?t=752

The details from this guy (yellow99BB ?) start about a half way down page two.

Also there's some discussion between other particpants about using Microwave Cooker transformers, etc, for parts.

Lots more research to do but TBH I'm a bit wary of the voltages and currents involved!

Anything over 35V (AC or DC) should be considered as 'dangerous'...

Regards
Peter

 

[weldnz]

Ebay Multi Welders

I have sold some Mitech welders, these have given me much greif,
I also tried mitech 160Super lasted for very short time and failed, still have it in corner, tried Greenbird 200super was a super160 with fake stickers to read 200, I had to buy two samples to get a order and then both were arrive smashed from poor packaging and also both of them the Plasma faulty, Personally I would steer clear of any welder that hasnt been in production by a professional brand for a long time,
I do sell CT416II from RILON and Plasma 40 from rilon they both have proved very robust and best thing they dont keep changing it so parts are easy to get, www.weldnz.com

 

[mishka]

The details from this guy (yellow99BB ?) start about a half way down page two.

Yoinks - there's just so much wrong with this guy's design and attitude that I don't know where to begin, other than to beg anyone considering this to think about life after death.

Seriously, though, unless you happen to have the parts of a dismantled plasma cutter in your workshop then it is much safer and cheaper to buy one.

Either that, or watch out next month for DIY plans for a home made argon regulator, made out of a tin can, rubber inner tube, a corkscrew and beeswax.

 

[peterd51]

Hi,

yes, I know what you mean...

I bought one off ebay today, much safer.

I'd emailed previous buyers of the same model and they said that they found they worked OK, cut up to 12mm as advertised.

I'll probably go as high as 6mm and generally 3 - 4mm so hopefully it'll do the job.

Regards
Peter

 

[tercero]

Old thread, new questions

I came across a set of plans offered by Joe Eichholz on a yahoo forum. The plasanator is an open concept plasma cutter that I'd like to build, but I wonder about it's safety. There's no isolation transformer between the rectifier and the secondary. He assures me it's safe if you don't touch anything while using it...but it makes me nervous. Nice guy and a good set of free plans if anyone's interested

http://finance.groups.yahoo.com/group/plasanators/?yguid=290185747

I'm just not sure how safe this is, and my inexperience with welding has me questioning if I should build this. Any input would be great.

Thanks,

Tercero
Ontario, Canada

 

[amron]

Hi
thanks for the link but the plans are not free. they cost us$13.
I've seen somewhere on the web plans for plasma cutter that are unsafe like what you have described.

 

[tercero]

Not sure where you came up with the $13, but they're free my friend . Join the yahoo group, go to files, and all the plans are there for the taking. Eric doesn't charge for his plans. I pulled them down on Thursday, looked them over and contacted Eric asking a few questions about the plans.

 

[shenion]

Not sure where you came up with the $13, but they're free my friend . Join the yahoo group, go to files, and all the plans are there for the taking. Eric doesn't charge for his plans. I pulled them down on Thursday, looked them over and contacted Eric asking a few questions about the plans.

Then why does the group say this: TO JOIN THIS GROUP YOU MUST BUY A SET OF PLANS. CLICK LINK BELOW WHERE IT SAYS GROUP EMAIL ADDRESSES.

 

[tercero]

You're right. It does say that on the main page (missed that somehow), but again the files are free in the files section.

Listed in the files section

Files
Name Size Creator Created
video/ blaster fun.WMV
Plasanator in action 647 KB joeginny2004
Offline Jun 5, 2008
video/ Just a good looksy.WMV
A closer look at the Plasanator 2612 KB joeginny2004
Offline Jun 7, 2008
application/ms-word Notes for Plasanator.doc
Notes on Construction of Plasanator 37 KB joeginny2004
Offline Jun 7, 2008
application/zip oil air burner plans.zip
Home Built Oil/Air Pump 917 KB joeginny2004
Offline Jun 5, 2008
application/ms-word oilair pump instructions.doc
26 KB joeginny2004
Offline Jun 5, 2008
application/ms-word Plasanator Parts List.doc
Updated parts list with foot pedal number 26 KB joeginny2004
Offline Jun 27, 2008
application/zip Plasanator Plans.zip
Plasanator Plans in one 4960 KB joeginny2004
Offline Jun 27, 2008
application/ms-word Plasma cutter Operation.doc
How the plasanator works 20 KB joeginny2004
Offline Jun 27, 2008
application/zip Rotary Phase Converter Files.zip
Homemade 5HP Rotary Phase Converter 1295 KB joeginny2004
Offline Jun 5, 2008

 

[classic2cv]

i've just had a go at joining this group and my membership is now pending

i'll let you how i get on