In a message dated 5/18/2003 9:32:17 AM Central Standard Time,
stefan_trethan@... writes:
> any new and nice ideas are very welcome.
>
>
> have all of you professional pcb drill presses or how do you drill your
> boards? (maybe homebuilt ones and a picture of them???)
>
> regrinding drill bits (for pcb) should be possible with a small diamond
> wheel? is this true / is this possible &good for one who can regrind a
> normal drill bit so that it works again?
Stephan:
To your first question: WOW, you would be talking close to $100,000 (U.S.!)
for a "professional PCB drill press", I think! At least the one CNC 4-quill
job I saw in operation at a local PCB shop. Now, if you mean just a manual
drill-press one could use to MANUALLY drill a prototype board, I have never
seen one with an adequate-quality quill. The quill-bearings would have to be
at least ABEC-7 for that! I bought ONE such bearing to rebuild a tiny 400
Hz/3-Ø motor I used to MAKE a PCB-drill, and WOW, talk about PRICEY! The
precision and concentricity of a quill must be MIND-BOGGLINGLY close to give
ANY life at all to PCB-drills! And the "attack" and feed-rate must be
properly set, as well.
Yes, PCB drills ARE re-sharpened with small diamond wheels, but again, you
are talking about some very fine drill-bit tipping equipment, NOT just the
diamond-wheel! The results you can get from manually touching a tip to a
diamond-wheel on a small "grinder motor" will vary so wildly you will wonder
if any "sharpening" is taking place, at all!
Now, the frustration of the first ¶ above inspired ME to brew my OWN "PCB
Drill", and control that with a now-LONG-discontinued CBM "PET" computer (see
photo). But I did that in '84! Were I to do another (or rebuild that one,
when it finally fails, which may be soon! Argh!), I would design the
"electronics" to work with a "PC", as those can be had now for less than the
postage necessary to GET them delivered to the door!
So look at the photo: <A HREF="
http://photos.groups.yahoo.com/group/cad_cam_edm_dro/vwp?.dir=/Home-brew+CNC+lathe&.src=gr&.dnm=PET-Controlled+X-Y+PCB-Drill.jpg&.view=t&.done=http%3a//photos.groups.yahoo.com/group/cad_cam_edm_dro/lst%3f%26.dir=/Home-brew%2bCNC%2blathe%26.src=gr%26.view=t">PET-Controlled X-Y PCB-Drill</A>
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