Subject: Re: drill bits

From: [email-masked] (David Wilson)
Date: Tue, 6 Aug 1996 23:51:25 -0600

On Tuesday, August 6, Roger Olsen said.
>I have found better life and cleaner cuts with the bullet pilot point bits
>than with the  genaric standard high speed twist drills, but longest life
>with the carbide tip. i have never had a solid carbide bit, or a cobalt
>bit. can someone comment on these types and or add other styles, makes, or
>suppliers to this discussion.

Thanks for the tip on the bits, (no pun intended). Have you looked at the
MSC big book? Must be 200 pages of bits! Feeds my bit fetish.

I'd like to know how best to sharpen bits. I have honed them with a diamond
lap stone for fine sharpening. Also, I've held them at the recommended
angles to my bench grinder, which works, but can eat 'em up pretty fast.
These bit sharpeners that you see at Northern, has anyone used them? Are
they worth $50 or whatever they cost? I don't go through a lot of bits but
it would be great to sharpen them up faster.

--
David
http://www.flash.net/~dwwilson/
[email-masked]

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From: Michael Spencer <[email-masked]>
Date: Wed, 7 Aug 96 01:49:39 EDT

> These bit sharpeners that you see at Northern, has anyone used them?
> Are they worth $50 or whatever they cost? I don't go through a lot of
> bits but it would be great to sharpen them up faster.

I've got a cheap little item that came, I think, from Sears Roebuck 25
years ago, about $20 then. Seems to do just fine from about 3/16" up
to 1/2" or a little bigger. It might be a nuisance if I had to sharpen
a couple of dozen bits a day, all of different sizes, because the
various adjustments are a little clunky, but really great when the
absolutely necessary bit turns out to be the one I trashed last
week. Looking closely at a freshly sharpened drill, I can see that it
has the relief on the trailing parts of the tip -- the feature that's
hard to get right by eyeball hand sharpening.

Someone gave me a wheel that he said was intended for drill bit
sharpening, turning the tip of the dirll (in my little holder) against
the *side* of the wheel. This also seems to be jes' fine.  I keep this
wheel and the sharpener set up on a dime store arbor driven by a
junker appliance motor and a belt. Avoids wheel changes on the bench
grinder and having to unbolt the sharpener when it's in the way.

My only basis for comparison comes for working as a millwright,
helping a guy drill 2" holes through the bottom of a lead-clad
stainless tank with a drill mounted on a wobbly forklift fork. (blech)
The mill had a heavy-duty pro pedestal grinder with a builtin bit
sharpener. I spent the afternoon running across the shop floor and
downstairs to sharpen and resharpen the 2" bits as they got chewed
up. Their sharpener was bigger and more elegant than my little
pot-metal one and the stone was somewhat finer but it worked just
about the same.

- Mike
-- 
Michael Spencer               (902) 543-8375
[email-masked]
URL: http://www.mit.edu:8001/people/mspencer/home.html
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From: "Steven O. Smith" <[email-masked]>
Date: Wed, 7 Aug 96 8:56:12 MDT

> it would be great to sharpen them up faster.

I'm one of the poor suckers who bought a sharpener from Northern.
Don't bother, it does a poor job of putting the wrong angles on. 

Darex is supposedly coming out with a 'home model' of their incredibly
expensive sharpeners, I think it was for about $150. They have a web
page at www.darex.com which does not show this machine, but has lots
of other info. The 'home model' has its own page at:
"www.drilldr.com./". This looks like a pretty nice unit-diamond wheel,
3/32 to 3/4" bits, 118 or 135 degree, split points, etc.

--
Steven O. Smith
[email-masked]