Re: [CAD_CAM_EDM_DRO] Engraving on Mill

Joe:

This is a task I have personally only tried one time, where I made some
simple lines and engraved "AC" on a tiny switch-panel, by-hand, not "CNC".
But I DID have some advice, both verbal, and "look and see, yourself!" from
an old (now gone) engraver-friend: An "engraver's point" is a 60° "half
point" (first, grind a 60° point, suggest you use a 1/8" or 1/4" dia.
solid-carbide "blank", so that the point is about 0.005" off-center with the
blank's O.D. Then, grind away HALF of that cone, so that the flat you have
just ground passes through that point, and the concentric center-line of the
blank. THAT, then, is a standard "engraver's point". OH, you have to pay
attention to which SIDE of the point you grind away, so that the cutting will
be standard-direction (CW looking DOWN, or CCW looking "up, into the rotating
bit"). If you have ultra-fine diamond grinding machinery and experience,
you might then grind an "edge flat" about 0.015" wide along the leading edge
of that "half-cone", and this may make that tip studier for metal-cutting.
Look at a standard cutter or even drill-bit. See the edge behind the "sharp
edge"? That's what I am trying to describe. That is concentric with the
tool.

Spin that at 10,000 RPM, using WD-40 for aluminum, or AIR if engraving
plastic or wood. OH, if plastic or wood, suggest you spin it at 30,000 RPM
if you can! Yep!

Jan Rowland