Re: 3D plasma/water-jet cutting

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "caudlet" <thom@...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Tom Foley" <tpf_ski93@>

wrote:

> >
> > Hi,
> >
> > I'm interested in plasma and/or water jet cutting on curved

surfaces.

> > The shape (mostly circles) would be controlled by the XY plane

and the

> > torch/nozzle normal to the XY plane (sort of a saddle-cut).
> >
> > Has anyone tried this?
> >
> > Can I control the torch to work distance accurately enough?
> >
> > Does the plasma torch need to be so close to the work that the

surface

> > curvature will interfere with it?
> >
> > Any ideas would be appreciated.
>
>
> Tom, the success if this will be dependant on the steepness of the
> curve. We have THC units where they are cutting 6" dia holes in 16
> and 18" pipe. The THC will do its best to hold a constant height
> above the material as it travels and if you have enoungh Z travel it
> will cut partially down the sides. As the angle changes from the
> vertical as you go down the sides, the torch has to start cutting

off

> the vertical at the tip (which it doesn't do well). If the angle

gets

> too severe the torch is cutting through much more metal and the tip
> volts will change.
>
> For smaller dia pipe you need to rotate the pipe and keep the head
> locked in a the rotational plane.
>
> I would think water jet would have similar problems but I don't know
> how it reacts to cutting at an angle.
>
> Last solution is to build a 4 axis on the torch head itself so you
> could actually rotate the cutting tool and use the Tangential

function

> in MACH3 (Don't ask me how though because I have never done it!)
> >
> > Tom
> >
>

Tom,
Are able to do a staight cut with a 6" hole in 16" pipe? That's
probably as severe a cut as I would need make. can you do that in
Sch 40 pipe?

This would solve most of my problems and give me time to learn how to
do a 4-axis solution for the tough jobs.

Thanks for the input

Tom