On Tue, 13 Dec 2005 01:20:21 +0100, soffee83 <
soffee83@...> wrote:
> Good point also on the pivot to bit distance and it's "skew" factor.
>
>
> Not to change the subject, but I was also wondering how bad it is to
>
> sink the bits further up in a chuck to shorten the amount of
>
> unsupported bit material? I fear that jaws gripping the spiralled part
>
> of it is not good. Like everyone's saying though, we really only need
>
> a little more than the board thickness.
>
>
> -George
>
Since the shaft is usually standard size and thus much wider that'd be
very hard to do.
However, the idea is good. I use a broken bit that did break 2mm down the
spiral part to enlarge/add holes free-hand. It didn't break again so far.
I think they'd last much longer if all bits were that short. I guess the
reason for long bits is many PCB houses drill stacks of boards at once. If
they break, they usually break right where the thin part starts, only good
to re-grind as scribe tips.
Maybe one could strengthen the unused spiral part with epoxy or something?
ST