you are surely right about hole quality...
but it fits my needs until now :-)
and the hss i just had around in a fairly high amount...
:-). you can circumvent the ∗melting∗ a bit trying to get the optimal drill
speed...works ok for me.
Cheers
Martin
----- Original Message -----
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, April 25, 2005 8:18 PM
Subject: Re: [Homebrew_PCBs] Re: Making PCBs - The other tasks
>
> On Mon, 25 Apr 2005 18:58:55 +0200, Martin Haverland
> <professional@...> wrote:
>
> >
> >
> >> I even drilled (and will drill in future) my single prototype pcb's
> >> completely freehand with a dremel-like drilltool (hss drills).
>
> While i agree with most of your post, HSS drills do not produce holes of
> the same quality as carbide drills.
> They get dull after a few and more like melt their way in than cut it.
> (proof: your solderpin story)
>
> This is however not a problem with many homebrew boards, and i think for a
> beginner freehand drilling is perfectly acceptable, i have used it for
> quite a while myself and as you say it is in fact faster than with a press
> and carbide drills.
>
> Note that sharpening the drill from time to time is a good idea, and it is
> totally non-critical if you get it nice, in fact once i broke a drill
> (yes, with HSS i only ever broke a single drill in a pcb, ever, and i did
> that for years), well, once i broke one i just continued and the broken
> edge drilled surprisingly well. it was more or less a straight break so i
> think maybe holding it straight against a grinding wheel would work just
> as well as normal sharpening.
>
> Doublesided is possible, you can even correct very slightly for offset.
> But note that the exit side has a even worse burr if there is copper than
> the side where the drill enters.
>
>
> ST
>
>
>
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