I assume you have holes etched in the pads, yes? Otherwise, how do you
locate the center of the pads?
I've got a Proxxon rotary tool and drill stand. It works great with
#80 resharpened carbide drills from Drill Bit City
www.store.yahoo.com/drillcity
I've also got a Supercircuits(.com) PC302XS camera and 12mm focal
length Micro Lens, which has about the right field of view and can
focus up close. I plan to use it with a 45 degree mirror and some sort
of glass covering (to protect from dust) and an old black and white
CCTV monitor to look at the bottom of the PCB while drilling. Work in
progress...
Cheers,
- Jan
On Fri, Jan 27, 2012 at 4:04 PM, bebx2000 <bebx2000@...> wrote:
> I also use this setup.I mounted a thin project box to the table with a laser pointer, a mirror at 45 deg and a pinhole inside to illuminate the bottom of the PCB. The pin hole is made by mounting a brass shim and drilling the hole with the smallest bit that you have. A degree of fiddling is necessary to get the laser beam directly centered on the pinhole. But once it is adjusted, the beam is strong enough to illuminate the hole to be drilled from below. There is also a bit of diffusion through the FR4, but the center of the spot of light is exactly aligned with the bit. the top of the project box serves as the table which is OK for small PCBs.
>
> The drawback is that once it is calibrated you can't remove the rotary tool or rotate the arm. This arrangement largely eliminates the depth perception problem; where the spot of light is, is where the drill bit will penetrate the PCB.
>
> Baxter
>
> --- In Homebrew_PCBs@yahoogroups.com, "tda7000" <Tda7000@...> wrote:
>>
>>
>>
>> I use a Proxxon FBS rotary tool in a Proxxon 140/S stand Lhttp://www.proxxon.com/eng/html/28606.php)
>>
>
>
>
>
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