Re: 3D plasma/water-jet cutting

--- 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

Hi Tom,

Making a rotary 4th axis is pretty simple, espically if your needs are
for plasma cutting.

If you CAD a pipe and show ID and OD, and then the cut, you will
quickly see that on the crest, you are cutting only the wall
thickness. on the angles, the thickness will increase. if you start
with a 4" pipe 1/4" wall, and try to cut for a 3" pipe, the sides on
the steep angles will be about 7/16 thick.

Also, if you draw in the torch head, you cannot get the heat to within
an inch of the cut !

By rotating the work, you really can just substitute the Y axis for
the rotary and not even change the software. Heck, you could just
move the motor, or swap plugs. POWER OFF !!!! of course !

This is pretty easy for pipes, even of different diameters.

Dave