Re: Engraving on Mill

--- In CAD_CAM_EDM_DRO@y..., "exeric1" <exeric1@y...> wrote:

> Does anyone have experience using a Dremel rotary tool on a CNC
> machine. I have a task requiring an ingraving on chrome plated
> aluminum. I have my doubts that it would be up to the task but it
> would sure be nice if it was - the price is right. Anyone know?
>
> Eric
>

It has been my experience that if you want the job to be professional
a Dremel is underpowered and has to much bearing play to do precision
engraving. At one point I got "cute" and added one of those cheap
50,000 RPM mini die grinders to my CNC engraver. I got nice clean
cuts that looked like they were made by a drunken computer
programmer...way too much tolerance in the tiny spindle! I have been
tempted to buy one of the Zip routers like they use for cutting
drywall and tile (for engraving wood) but so far have chickened out.

I tried all kinds of engraving bit solutions (short of buying a REAL
engraving bit). I bought 1/8" Carbide V bits used in the PC Board
industry and they worked okay but when I broke one and decided to
grind my own on my diamond grinding wheel, I made a breakthrough. It
took grinding it under a magnifying glass and several trys but now I
get nice clean letters in the 303 stainless pencils I make. I used
the standard v shaped tip ground flat halfway through the bit and
with a small degree of relief behind the cutting edge.

I also quickly found that I had to re-engineer my cutting head and
make it floating with adjustable down pressure. If your material is
not absolutely flat (or level in the case of rotary engraving) you
get a serious varience in the letters due to depth fluctuations.