Homebrew PCBs

> Wait a minute. Most of you guys are saying that I should drill by
> hand instead of by using the press. I thought that what the press was
> for to get more accurate drills if that is the correct word. Can you
> guys elaborate on why hand drilling is better?
>
>

No, it is not better at all..

Carbide drills will produce better quality holes, less burr, straight, 
etc..

But you need to align the drill tip and board exactly.

with drilling by hand the hole in the copper catches the drill and centers
it much easier.
The disadvantage is you can not use carbide because it would break.

If you have a press already i would use it. you have to align the drill 
properly,
that is the only way then.

the other two possibilities are a cnc or such a professional optical 
device.
You can see them at <http://www.megauk.com/pcb_drilling_machines.php> but 
the page is down.

It is a "upside down" drill press. the drill comes from the bottom, on the 
spot on the top
a viewing device is aimed. it has a screen and a target drawn on this 
screen. you simply
line the pad up with the target and press a switch. then a foot comes down 
to hold the pcb
and the drill comes up.

We were thinking it must be possible to use a camera under a standard 
drill press for this too.
maybe you need to use a mirror or something because the camera lens would 
get full of dust.
maybe a vac sucking the dust up is the best way.

Then use a old small TV to view the picture. you can even draw rings on 
the tv to aid in centering.

It is most likely you need no foot holding the pcb here, the pressure of 
the drill helps holding it still
while in the upside down setup it lifts it up. you also can simply operate 
the drill press manually.


I guess it is a good approach if you already have a press and carbide 
drills. such a camera is really cheap
and a small TV is no problem i would say..


Stefan