Homebrew PCBs

On Fri, 29 Jul 2005 12:46:04 +0200, Philip Pemberton  
<philpem@...> wrote:

>
> I would if I knew how to do it... I've got a pair of dead Laserjet IIIs  
> lying
> around (full of mechanical bits) and the guts of an old scanner, not to
> mention the old drill stand (=crap) and the various offcuts of FR4, wood  
> and
> aluminium sheet.
> The problem is working out how to put it together to make a drill press
> that'll take the Dremel...
> Later.


might make photos of mine... in fact there are some..

<http://trethan.at.tf/pub/img1/>

all that start with "drill".


I have made some changes in the meantime, the bearings went down in the  
back, and that last wood piece that holds the drill can now be tilted down  
(using shims) to achieve a more tangential movement.

Also, i made a stop close to the drill (actually it is a screw clamped  
with the grinder clamp).
This is better than the stop at the side because it does not twist the  
drill when it hits the stop, and it holds the pcb down in that critical  
moment where the drill tries to lift it. Since i made those changes i  
haven't broken any drills.
I clamp a machine vice to the end of the pivoting arm that sticks out the  
back, which has just the right weight to balance the arm. You could also  
use a spring.



You don't need the "box" below the drill platform, i made it because this  
unit is prepared to hold a simple projection mechanism to magnify the  
drill area, but i doubt i'll ever get around to adding it. but the box is  
neat to store drill boxes and stuff.
When drilling a lot of holes i add a lamp and a vacuum.


Now for making the whole thing easier to build, you can use piano hinges  
instead of the thrust bearings.
Instead if the complicated pivoting frame you can use a triangular plate,  
one corner holds the drill in a hole, and the opposite edge is hinged.  
another board as base and you are done. (might need a spacer at the back  
to get the correct height for the hinge).

ST