Re: plasma vs laser vs browns gas for cnc router cutting

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Robin Szemeti <list@r...>
wrote:

> On Monday 12 January 2004 04:48, turbulatordude wrote:
>
> > > process when cutting thick metal. Its just metal burning in
> >
> > Oxygen ... as it
> >
> > > always is ...
> >
> > The flame is purported to be in the 6,000 degree range so it would
> > seem to be considderably higher than acetelene(sp?)
>
> acetylene isn't particularly hot. What 'sells' acetylene is its

high energy

> .. it carries a LOT of heat (in terms of joules) rather than being

at a very

> high temperature .. the 'browns gas' is just an oxy-hydrogen flame,

its

> 'hotter' but as I understand it, has a lower energy density.

I have read this. The Hydorngen/Oxy torch has a higher flame temp.
That is a plus point for some projects.

>
> > and since it also
> > is reported to work on aluminum, the cutting is not just the metal
> > buring like in steel torch cutting.
>
> not convinced ....
>
> > The old Harbor Freight product, which I think may be discontinued,
> > listed the tip as only 1mm wide. That would put the 6,000 degess

in

> > a 1 mm point. The the huge volume of gas, but actually a small
> > volume.
>
> I'll make a wild guess here ... if they are putting 25A at 240V

into their

> 'electrolizer' they will be getting at most 6Kw of energy out (I@ll

guess the

> efficiency is around 75%, lets say 4Kw out) ... I'm putting about

25Kw into

> my plasma, 20Kw of which ends up at the business end. I'll take a

guess and

> say that the plasma will cut quicker ...
>
> There were no cutting speed charts I could see on the site, if it

WAS quicker

> they would be shouting about it ...

Actually, it was more like 9A as 110VAC, but remember the flame tip
was only 1mm. We are not talking an industrial machine here. This
was offered more as a hobby torch, or jewelry repair type device.

I have not seen very much in the way of welding specs, but as you
might imagine, the seams would have to be pretty small.

Ditto for cutting. If you are cutting with an oxy-acetelene torch,
you are really burning the steel. Aluminum and Stainless are not
easy to torch off, but if you are talking sheets of metal, or thin
sheet metal and a 1mm tip, the parts could be much higher accuracy
than your Plasma.

The lack of much awareness would indicate it is NOT a replacment for
current technologies. But, we home-brew guys often can find uses for
very odd technologies.

I see the possibility of a CNC plasma cutter type table. I'm
thinking much higer accuracies than plasma on thin parts.

Torch head height control would be an interesting problem as there is
not an electrical circuit for feedback of the process. My first
idea is a fixed torch and moving part. That would allow optical or
temperature monitoring of the cutting progress.

Dave