Homebrew PCBs

----- Original Message ----- 
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, January 10, 2005 7:38 AM
Subject: Re: [Homebrew_PCBs] Re: PCB drill viewing mechanism... reviewed


>
>
>
> > I think the best approach is like the commercial units. Have the drill
> > under the table. Mine is above the table, but will convert it sometime
> > down the track. The advantage of having the drill come up from the
> > bottom is you have a flat table top to work on, with no drill motor in
> > the way. Of course this means you now must have a means to view the hole
> > location from above.
>
> I think that has the big disadvantage of the drill lifting the PCB,
> requiring a hold down foot or firm pressure by hand. I do not see big
> disadvantages of the upside-down version.

The old Excellon drilling machines drilled from underneath, with a clamp to
hold the PCB that locked it when the drill was actuated by a foot pedal.

Leon