Re: [CAD_CAM_EDM_DRO] Engraving Tool vs. Small End Mill

At 15:27 26/02/2003 +0000, you wrote:

>I want to use my CNC Sherline mill to engrave a grid pattern on some
>aluminum. I want the size and depth to appear about the same as if
>you ran your scriber over the surface. I have seen both small end
>mills and engraving cutters available. Which would be the best choice
>for this application? What are the pros and cons of each? Is there
>some other tool I should use? I am just begining to learn to use my
>CNC conversion and have not tried any engraving yet.

Attempting to do a cut that shallow is going to be interesting unless the
surface has been made truly flat, as sheet material can flex a few thou,
which would show up as a significant difference in depth of cut with what
you are doing unless you use the kind of floating toolholder that is used
on engraving machines. So if it is sheet material you are going to engrave,
the first problem will be keeping it flat enough to work on. Try double
sided carpet tape, but be aware that if the cutting heats up the material
too much, the adhesive will melt - also, with rolled sheet metals, the
stresses caused by the rolling process can cause the material to curl as
you strip away the surface layer.

Having said that, I have had reasonably good results using a V-tip
engraving cutter on sheet material, albeit at more deptht than you are
talking about (this was for a clock dial where the engraved numerals were
to be later filled with black wax, so the cut could be reasonably deep -
see various pics at
http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/Tony%27s%20files/)


Regards,
Tony