AW: pcb's

[Magnus Danielson]

> 
> My few cents ( ... Pfennige, actually):
> 
> I think the worst thing of DIY pcbs is drilling all these holes! So I don't 
> think
> heat transfer foils help you save much time.
> I use the good old photo method. A photo-sensitive euro format pcb costs
> around 2 Dollars, a xerocopy on a good foil another Dollar, chemicals
> for one PCB are well below one Dollar.
> Things I had to invest in (once in a lifetime): An exposure frame with UV
> flourescent lamps: 200 Dollars (stay away from these cheap UV lamps,
> they always die of overheating!) and an etching machine that blows air
> thru your etching liquid: 100 Dollars.

Agree... getting proper exposure and etching equipment pays of in the longrun.
But as always... the initial threshold (money).

> With these devices, I completely etched a set of 10 eurocards for my
> vocoder in a single evening. But as I said, *drilling* thousands of holes
> takes much much longer.
> BTW, I prefer the cheapest pcb material available - its far easier to drill
> this than the expensive epoxy material.

Yeah... drilling can kill you... from my experience is a good drill in a stable
drillstand necessary, you must be able to slowly and well contoled lower and
rise the drill.
Also, the use of hardmetal drills (not music :) is advantagous but you have to
be carefull in handling them. From experience I know that they break easilly if
you move the PCB while drilling. Therefore you must force yourself to keep the
PCB still and not work up a stress... go slowly and slowly work up a pace... 
when you loose it drop back to slowly again...
To keep the PCB still you migth be tempted to keep it in some support, this is
a good thing only if you can easily and smoothly move the pcb. Excessive force
of any kind is out of the question for moveing the pcb. Also, a good pcb 
support
should not apply much force to the pcb in parallell with it's flat surface
(that is, not pressing it's edges together) since this may make the pcb bend.
Applying an steady stream of air to the drill area is also wise....

If you ever get around to drill a teflon card, you will know what I mean :)

Magnus