Homebrew PCBs

Thanks for the info.

I took a guess at a starting point and used 5400 RPM & 8.6 IPM on a .042" dia carbide bit. Seemed to work just fine, had some burs on the back side but they sanded off without much effort.  I was using some masonite as a backer but possibly I need something a little more dense to help reduce the burs.

Eventually I am going to build an accessory high speed spindle attachment to get the RPM up to 25K to 30K.

I also need to build some sort of holding fixture possibly a vacuum fixture to hold the blank boards.

Craig

--- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@...> wrote:
>
> 
> I just finished up my CNC quill drive conversion my Bridgeport and would
> like to use it to drill boards.    I have not found a reference to what 
> speeds and feeds to use for drilling.
> 
> I am looking for the  surface feet per minute and feed per turn numbers
> for  small carbide drills in FR-4.    My 5400 RPM maximum  going to be
> well below the 30,000 to 60,000 RPM used by a real PCB drilling spindle
> but it should still work fine if  I use the correct feed rate.
> 
> Anyone got a reference for these parameters.
> 
> 
> 
> BP Quill Drive
> <http://picasaweb.google.com/lh/photo/B-uAtxYUicys82cFdd5HYg?feat=direct\
> link>
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>