Homebrew PCBs

Hello Group 

I have received many great suggestions.  Thanks very much!

It seems like all of them would work.  Although bottom drilling seems
like the most accurate 'manual' method, it would be impractical with my Dremel drill press stand.  Likewise, placing a front surface mirror around the drill bit would be mechanically cumberrsome.  After thinking about it for a while, I have decided to place an angled FS mirror and CCD camera beneath the drill platform.  This setup would have the additional advantage of keeping all elements aligned and would be very easy to calibrate.  Although there may be a problem with lighting the underside of the drill platform, my CCD has led illumination.  Hopefully, the mirror should serve the dual function of conveying the image and illuminating it.  

Yesterday, I mail ordered an FS mirror, got some wood and built the contraption.  Hopefully, the contraption should work after the mirror arrives!

Thanks again for all your sage advice!

Cheers

Chris (W1EH)
--- In Homebrew_PCBs@yahoogroups.com, "schenckcharles" <schenckcharles@...> wrote:
>
> Hello Group
> 
> I have a quick question about precision drilling of home made PCBs.
> 
> Because of poor eyesight, I use a CCD microscope next to my Dremel
> Model 300 drill press stand.  Although this set up is a big improvement
> over doing thing solely 'by eye', there is a parallax error introduced
> between the location of the retracted drill tip and where it eventually comes in contact with the PCB.  Once I saw a milling machine where one
> was able to sight straight down into a bulls eye.  Is there a way to 
> rig mirrors to do this?  
> 
> P.S. Sincle sided boards are no problem, as I can hold them up to
> strong light and position a hand held rotary tool with good enough 
> accuracy.  
> 
> Any suggestions would be appreciated.
> 
> Cheers
> 
> Chris
>