You need a drill press / stand to guide the drill.
You can either buy or build.
If you build, you can easily make a pivoting drill stand, mount the
drill motor to an arm about a foot long, and hinge the arm on the
other end so that it can swing up and down. The couple of millimeters
in travel will be straight enough not to break drills, even though the
drill moves in an arc not a straight line.
You can also use sufficiently thin and flexible arms and do away with
the hinges. In this case you should have two arms to guide the drill
in a parallel motion (like a double wishbone suspension setup).
Mind that the drill needs side-to-side guidance too, so you need a
wide arm, a triangular shape will work well too and you can simply cut
it from plywood and use a piano hinge at the back edge.
You also want a depth stop, and some spring action return is nice.
Make provisions for dust extraction with a vacuum cleaner if you drill
glass fiber boards.
If you buy, you pretty much just need to make sure there is no
excessive play in the apparatus.
BTW I recommend to use a Proxxon drill instead of a dremel. It comes
with more precise hard steel collets and offers less runout. The cheap
12V versions are plenty strong even for large holes in PCBs and also
much quieter than a dremel.
ST
On Sat, Apr 18, 2009 at 10:06 AM, Alessio Sangalli <alesan@...> wrote:
> I do not plan to do much through-hole (for this reason I am reluctant in
> investing in something pricey/bulky) but I occasionally need to make holes.
>
> I have bought some carbide bits at harborfreigh and I have a dremel; on
> the other hand, I've been told those bits can break easily (well I
> think one can break them just by watching them too much, they are so small)
>
> What is the recommended solution?
>
> Thank you!
> Alessio