Homebrew PCBs

Joe,
So far, most has been just tying to make things 
work properly. Calibration needs to be done 
initially to find out how wide a path your 
actually cutting. If you are cutting wider than 
you think you are, your making thinner traces! 
Bit wear usually shows up as excessive burrs or 
if you have damaged the tip (easy to do if your 
using small angle bits (30° or less) the quality 
of the cut will show that you need to do something.

Art
Country Bubba



At 12:29 PM 12/13/2012, you wrote:
>On Thu, Dec 13, 2012 at 11:41 AM, Art Eckstein <
>art.eckstein@...> wrote:
>
> > **
> >
> >
> > Joe,
> > I forget where I saw it, but one rule of thumb is 1IPM per 1000rpm of
> > the spindle. It seems to be a good starting place and of course might
> > need tweaking depending on your exact setup.
> >
> > In the bit calibration program, yes I do have some problems with
> > trace width less than .005" and I have not yet tried it in FR4. By
> > the way, if your interested in the bit calibration as developed by
> > Poul-Henning Kamp, you can find the information here
> > <http://phk.freebsd.dk/CncPcb/calibrate.html>
> >
> > Art
> > Country Bubba
> >
>
>Hello Art,
>
>Quick question, How often do you run the above calibration to check if the
>bits have dulled or if the cnc machines' runout is above tolerance? Or, is
>there some method that you use to figure out the dulled bits?
>
>Thanks
>Joe