LOL!
I can just picture me standing in front of a grinder today (with my
bad eyesight) trying to hand grind a point on a .035" carbide drill
bit :-) I can barely grind the .250" drill bits anymore :-(
The more I think about it though, I am going to pick up either a
soft-green wheel or a diamond wheel. I plan on giving the isolation
milling a try when I get the little machine done (sometime during
the next century). I suppose someone makes bits for isolation
milling but I have not seen any in the grab-bags of bits I have been
buying.
So, in the spirit of doing everything else, why not make an attempt
at grinding tiny bits to drive myself crazy ;-)
Chris
--- In
Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:
>
> On Tue, 25 Jul 2006 21:53:31 +0200, lcdpublishing
> <lcdpublishing@...> wrote:
>
> > Yeah, I should keep the broken ones, if for nothing else, to sell
> > for scrap value. I don't have any means of repointing or even
> > grinding carbide here. I do have enough grinders I suppose that
I
> > could put a soft wheel or a diamond wheel on somthing though. I
> > guess I better start saving them!
>
>
> When i was at school we made scribe tips out of them broken ones.
Still
> have mine somewhere, it will work as a glass cutter ;-)
>
> There were PCB drills with a soft shank where they could cut a
thread for
> screw-in tip replacement. But at some point they made them solid
carbide.
>
> I keep them all, but have yet to find a good use (lacking a
diamond wheel
> too).
>
> However, if you break one by chance with a short section of drill
spiral
> remaining they can be used to drill or enlage holes in populated
boards
> "freehand" where a normal length drill would break. I wish they'd
make
> them with only 2mm or 3mm of thin end. They'd never break! Conrad
> Electronics from germany used to sell spear shaped bits like that,
not
> sure if they still do.
> It might be possible to grind them shorter, but maybe it is too
tricky to
> do by hand (although i'm usually fairly good at drill grinding)
>
> Anyway, with the pivoting drill press i managed to make some quite
dull
> before breaking them.
>
> St
>