Homebrew PCBs

--- 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