I mill my circuit boards. After making my outline artwork I go back
and put a dot in the center of each pad. During milling the dot
becomes a starter hole. I use the 60 degree milling bit from Think &
Tinker. It looks like a tiny drill bit mounted on a shaft. After
milling, it is on to my Dremel drillpress. I own one of those old ones
where the bed comes up instead of the Dremel moving.
--- In
Homebrew_PCBs@yahoogroups.com, "gettingalongwouldbenice"
<gettingalongwouldbenice@y...> wrote:
>
> How do you get the holes in the right place?
> I tried using a manual dremel press.
> For something like a 40-pin dip header...the pads are tiny
> so you have to be right in the center. Also the header won't
> fit if any of the tiny holes are the slightest bit off.
>
> I stuck a dremel on a 3-axis stepper assembly. Drills holes
> in accurate relative position, but never got around to writing
> the code to correct for board rotation in the fixture.
>
> Thank goodness surface mound don't need no stinkin' holes ;-)
> mike
>
> --- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@k...> wrote:
> >
> > Earl,
> > I own several Dremel MultiPros. I bought a Foredom Number 30
> > handpiece thinking it was better. If you don't overtighten the collet
> > of the Dremel it has less runout than the Foredom Number 30. The
> > Dremel is under .003 and the Foredom is around .006 I suspect the
> > Jacobs chuck is not as well built as it looks. I bought a sound meter
> > also. The foredom is only a little quieter than the Dremel. The
> > Foredom makes low pitch noise and the Dremel is a high pitch. I ran
> > lots of test during my quest for a quiet spindle. I attached a pulley
> > to the back of a Foredom handpiece and drove it with a pancake motor.
> > Almost no noise at 18,000 RPMs but too much runout!
> >
> > http://crankorgan.com/pancakespindle3.JPG
> >
> >
> >
> > John
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "Earl T. Hackett, Jr."
> > <hacketet@c...> wrote:
> > > Drilling PCBs is a problem. Right now I'm tending toward using my
> > Foredom handpiece in a drill press attachment with an XY table. The
> > boards I'm building are no more than 3" x 5" so a big XY table isn't
> > required. Foredom tools are very high quality. They use collets
> > rather than a Jacobs chuck. Runout is minimal and they are designed
> > for side as well as in line loads. The motor I have has a max speed of
> > 15,000 rpm. That's a bit slow for PCB drilling, but it is primarily a
> > wood carver. Foredom has pneumatic quills that will run at 300,000
> > rpm. That's a pretty good clip and should work well in PCB material.
> > 20 years ago the PCB industry was running quills at 120,000 rpm and
> > looking for more speed. Well, here it is at a price you can afford.
> > >
> > > [Non-text porti
> > ons of this message have been removed]