On 21 Nov 2006 06:04:25 -0800, "RayV" wrote:

A while back I had to drill out a bolt and went through several bits.
Dulling them, snapping them and as a bonus I also snapped a misnamed
easy-out. Buy new bits? Nah, they cost too much for a decent set
besides I have probably 100 drill bits. I gotta figure out a way to
sharpen them.

DAGS. Keeps coming back with buy a drill doctor. I find the thing
from Lee Valley and others that holds the bit at the correct angle to
bench grinder for $10.
http://www.leevalley.com/wood/page.a...072,43086&ap=1

The DD and the angle guide don't seem to be doing anything fancy so I
think why can't I just do it myself. Here's what I'm thinking please
tell me if you think it will work.

The Drill Doctor and the angle guide are almost certainly doing much
more than you think. Twist drills are deceptively complex.

Cut a wedge at the proper angle
Chuck the dull bit in my drill press
Clamp the wedge and a stone or fine file to the DP table
Lower the dull bit against the stone or file
Keep bit oiled and cool
Done

Nope. Take a look at the tip of a fresh drill bit- in particular, the
fact that the tip is not pointy like a pencil.

You can sharpen them freehand on a belt sander or fine grinding wheel,
but it takes a little practice, and it really helps to have someone
show you how in person. I'll try to descibe it, but I don't know how
much it will help.

Basically, there are two huge things to worry about- The first is the
tip profile. It should look like a forward slash ( / ), and not a
point. The middle of the slash should cross the center of the bit.

The second is the "wing" angle. It should be 135* on most bits.

To get the profile right, you need to start grinding near the cutting
edge (be careful not to round it off), and rotate the bit until it has
ground that entire side. You can do this several times, but you're
not rotating the bit all the way around. Once you're happy with the
first side, lift the bit off the wheel, and rotate it 180* degrees,
and repeat the process until the tip profile is centered.

It takes a fair amount of practice, but it's not too tough once you
get the hang of it.

The drill sharpeners have an indexer to get the bit in the right
position, then lock it so that it is properly aligned with the cams.
As you twist the holder, it rides on cams to raise the bit
appropriately as it nears the back of the grind. Well worth the $$$
to get one if you've got a lot of bits to sharpen, IMO.