On 2011-12-24, Ed Huntress wrote:
On Sat, 24 Dec 2011 07:45:38 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

"DoN. Nichols" fired this volley in
:

Check this out and scroll down to the first non-atavar photo.
(It is large enough to get your attention anyway. :-)

No binaries get through, Don. Can you just list a link?

I didn't see Lloyd's posting for some reason -- perhaps in the
killfile in part if not the whole name?

I didn't post a binary, so of course it did not get through. :-)

I thought that I had posted a link, but apparently forgot to cut
and paste it into the article.

Here is the URL which I had found befo

http://www.practicalmachinist.com/vb/general/dubbing-drill-bits-183967/

Lloyd

You probably have the idea by now that you want to avoid positive
rake. That may not be a problem anyway, drilling in thin plate, but
the idea behind purpose-made cutters for brass is to avoid any
significant positive rake that would make the cutter dig in. In the
case of a drill bit, a positive-rake cutter can start self-feeding,
tear up the hole, and possibly break the bit.

Indeed so.

Someone described stoning the lip so the cutting rake is zero --
parallel to the axis of the bit. That's what I do. It only requires a
very small flat. If I had to cut a lot of holes, I'd just buy a
purpose-made bit for the job. But you really don't need it for brass.

Indeed so.

If you want a better finish and you're going to make a lot of holes,
consider a drill/reamer combination tool, and nub off the drill-lip
rake with a small slipstone.

Hmm ... an interesting product. I don't have any of those,
though I do have the combination drill bit and tap which work nicely in
a tapping head in the drill press. (Not tried on brass, yet. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---