Re: [CAD_CAM_EDM_DRO] Re: 4-AXIS FOAM CUTTER

> 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.

The simplest case for a model airplane wing involves an airfoil
template attached to either end of a long rectangle of foam. A
nichrome wire is stretched across a bow-like frame and heated with
electric current. The operator(s) carefully guide the wire across the
templates. It's important that the wire always be connecting related
points on the templates, otherwise it will cut too deep in the center.

Presumable the CNC version of the system replaces the templates with a
2-axis motion system at each end of the wire that traces the outline
of a software-defined airfoil section. A four axis controller is need
if the wing is to be tapered, ie, have a different section at each
end. (Typically the tapered wing would be made in mirror-image left
and right halves that get glued together and covered with reinforcing
skins of balsa, thin plywood, or plastic).

Chris

--
Christopher C. Stratton, stratton@...
Instrument Maker, Horn Player & Engineer
22 Adrian Street, Somerville, MA 02143
http://www.mdc.net/~stratton
NEW PHONE NUMBER: (617) 628-1062 home, 253-2606 MIT