Re: 4-AXIS FOAM CUTTER

Hi Fred,

Thanks for the examples! Yes, I can see the letters now. Didn't know
they could use foam for letters on signs! The wire EDM being used to
make extrusion dies sounds like a perfect solution for an otherwise
complex (impossible) machining task.

I'm anxious to get my new Vector Manual! Probably in a few days. I'll
check out the wire4ax.ccd file too.

I was wondering about the airplane wings, I never could see how they
could cut a complex form like a tapered wing with a hot wire!

Alan KM6VV


Fred Smith wrote:

>
> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Tim, list,
> >
> > All this foam! I'd heard about cutting airplane wings for model (?)
> > aircraft, but what else is done with it? Casting molds? I know,
> Santa
>
> A very common application is cutting dimensional letters for signs,
> cut with angled sides. Pick a tru-type font, draw the top shape,
> draw another outline at a different Z depth and slightly larger or
> smaller. The foam (or wire EDM for steel) will be cut to the same
> form. This is usually cut from foam sheets, and the X-Y-U-V axes are
> parallel to the X & Y on a vertical mill.
>
> Some common wire edm forms are die clearance, side clearance on
> grooving/forming tools for lathes, and extrusion dies for aluminum or
> plastic. The entrance hole for an extrusion die is nearly round, and
> the exit is shaped like an H or an L , or a U to make extruded
> aluminum channels.
>
> > I can't visualize the moving of 4 axis; pairs of "hot wire" ends, to
> > shape the foam. I'd like to see a movie (demo) of that! The wire
> cuts
> > a plane, can it be thought of (and manipulated like) a wood rasp?
> This
> > motion is NOT like any tool path I can think of. A ball mill
> moving in
> > 3D I can visualize, this wire tilting and moving I cannot.
> >
>
> See page 222 in the new Vector manual or file open wire4ax.ccd in the
> Vector installation directory.
>
> Hot wire is somewhat limited for making airfoils, in that it cannot
> make a fully controlled changing airfoil cross section. It can make
> a varying one, but the only control points are at the ends. Hot wire
> will not let you make a "bulge" in the center, nor will it allow the
> cross section to extend outside or inside any space defined by the
> end points. If you need an airfoil that has a twist like a propellor
> or turbine blade for instance, it quickly can fall outside of the
> capabilities of 4 axis wire cutting.
>
> Best Regards,
>
> Fred Smith
> IMService