--- In
Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Sun, 02 Oct 2005 16:14:15 +0200, Andrew Mawson <andrew@m...>
> wrote:
>
> > I tend to use resharpend drills (as they are cheaper and so am
I !)
> > but
> > use a collar to set the length to a standard so changing mid way
> > through a board is less hassel.
> > The 1/8" drill shank has a 3mm collar forced over it so is a very
> > tight
> > fit.
> > Actually adjusting the collar to sit so that the drill tip (or
more
> > critically a fishtail cutter tip)is exactly where it should be is
a
> > bit
> > hit or miss and I wondered if anyone else uses this method and if
so
> > has a magic way to adjust them.
> > I sat down to design a screw device to force the drill through the
> > collar until it touches a contact and lights an led, but then
> > realised
> > that the collars vary in thickness and the critical reference is
from
> > the TOP of the collar to drill tip.
> > AWEM
>
>
> I have a screw device too, i didn't sit down to design much
though....
>
> It's just a large nut with a short piece of copper tubing soldered
to it,
> and a washer soldered on the end of that.
> There are also two large screws, one with a small indentation and
one with
> a small stud. the first one is used to move the ring around and the
second
> one can push the drill out all the way if i need the ring for
another one.
>
> All the rings i have are same thickness, and i manually set them
(maybe
> 0.2mm tolerance). If the rings are not the same one could build a
similar
> screw adjuster that uses the top side as reference.
>
> ST
Stephan,
Can you pop a picture in the photos section?
Cheers,
AWEM