I have a couple of Dremel drill presses, the old one where the table
raised to the bit and the new one that lowers the Dremel tool into
the work piece.
I asked at mt dentist and they saved, autoclaved and gave me a whole
small bag of dentist drills and burrs. That was several years ago,
not sure with all the concerns for dieases these days they would do
the same thing. The bits seem to work the price was good.
I have made circuit boards from tapping out the hole pattern with a
sctatch awl and connecting the "dots" with a Sharpie, using masking
tape, Hunter Speedball pens and a special lacquer resist a chemist
friend made, Press and Peel Blue, Need to try the photo paper method
I have a GBC laminator I modified to slow it down.
Photo etching using a overhead projector for the exposure lamp,
worked well too. I removed the actual projection lens and used the
projector "table" top. Did pretty good, exposed a circuit board in
about 30 seconds. I lay a piece of white plexiglass on it and utilize
it for a light table too.
Anyway the Dremel drill press always worked well for me. I am now
assembling a CNC router for my PC boards and should have it
operational over my annual Christmas vacation. Should be fun to watch
it chew through the copper clads board and drill the holes for me.
Gary Fiber K8IZ
--- In
Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...>
wrote:
>
> Hello,
>
> My name is Jerry Kaidor. I've been messing with electronics
for
> many many years. Also put in a 20-year stint as a firmware
developer.
>
> The other day, I was doing a project with a PIC16F867A
> microcontroller. Built up the circuit on one of those proto boards
> that have a grid of three-hole lands. The resulting forest of
little
> green wires did not inspire confidence. Neither did the smoke that
> came out when I powered it up :).
>
> So I decided that a PCB would be more appropriate. Found this
> group, read with interest about Toner Transfer. I had tried this
> about 10 years ago, it didn't work at that time. Like many things,
> the devil is in the details.
>
> This time, armed with better info, I downloaded the expressPCB
> software ( can't beat the price! ). I designed a one-sided board
for
> my project and printed it onto a sheet of Epson photo paper that I
> had laying around. Found a gungy old piece of copper clad in the
> garage, spent about a half hour cleaning it off with 000 steel
wool,
> paper towels, lacquer thinner, more paper towels, cosmetics buffs,
> etc etc. Transferred the printout with my wife's clothes iron.
> Wow! It came out perfect!
>
> The only problem ( and I realized this unfortunately when it was
> already mostly etched ) was that it was mirror imaged. I had used
a
> function in my printer setup that causes the printer to print
mirror-
> imaged - but apparently it wasn't needed. Grrr! OK, I'd just
> solder all the parts on the top :). Or just do it again...
>
> To play with the process, I started drilling holes. Hit a
snag.
> My smallest "ordinary" drill bit was a #60. It was just too big.
I
> also had some little tiny PCB drills that I got at the ham swap
some
> years ago. Too small! (.8mm, I think )Also, chucked in my giant
> tabletop drill press, the tiny bit only lasted three holes before
> breaking.
>
> So - how does one drill these holes? I'll pick up an assortment
> of PCB drill bits today, but I don't think my giant drill press is
> going to work. Alternatives I see:
>
> ∗ Jameco lists a little drill and press for about $60.
> ∗ There is a Dremel drill press accessory for about $50.
> ∗ I have a Sherline milling machine. Sherline lists a "sensitive
> drilling attachment" that chucks into the mill. Basically,
> the mill only drives and holds the attachment - you move it
up
> and down via a knurled ring. This really looks like a hot setup,
but
> it's not cheap - $110.
>
> - Jerry Kaidor
>