I use a great deal of drill bits in both metal and wood, and have decided to
try my hand at sharpening them. Is there a particular angle for sharpening
drills both for wood and metal. The largest drill i ever use is 1/2 inch. A
local hardware shop, sells a tool that attaches to your smooth stone bench
grider.

Any help is appreciated.

Peter

On Thu, 06 Sep 2007 22:29:50 GMT, "Raven"
wrote:

Any help is appreciated.


What kind of drill?

http://en.wikipedia.org/wiki/Drill_bit

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** http://www.bburke.com/woodworking.html **
---------------------------------------------

All are metal drills, sorry for not mentioning that, most of my actual wood
drills are still very much sharp, as i tend to use metal drill bits in wood,
as they are cheaper to replace. How-ever, now that 3 of our 5 hardware shops
here in town have closed down, the driving to and fro is starting to cost.

Thanx

Peter

"B A R R Y" wrote in message
...
On Thu, 06 Sep 2007 22:29:50 GMT, "Raven"
wrote:

Any help is appreciated.


What kind of drill?

http://en.wikipedia.org/wiki/Drill_bit

---------------------------------------------
** http://www.bburke.com/woodworking.html **
---------------------------------------------

"Raven" wrote in message
...
I use a great deal of drill bits in both metal and wood, and have decided
to try my hand at sharpening them. Is there a particular angle for
sharpening drills both for wood and metal. The largest drill i ever use is
1/2 inch. A local hardware shop, sells a tool that attaches to your smooth
stone bench grider.

Any help is appreciated.

Peter


This is a really hard question to answer in text format. It has been asked
many times in the past and I would urge you to DAGS on the topic, (something
that nobody seems to do anymore). There have been some really good write
ups that several of us have posted that I think you'll find helpful. It's
not a simple two sentence answer.

--

-Mike-

Boy, has this one been answered. There was a long time
contributor to usenet who is no longer with us who explained it
all better than anyone has or will. I am proud to post this as
some of TeeNut's finest work:

Jim, You are dead right about not being able to grind a drill
without mechanical
help! Well here's how you create your own "6 Million Dollar
Bionic Darex" ;^)

Let's assume we are going to sharpen a 3/8" diameter, 2MT shank
drill..it is
about 8" long (these figures are arbitrary..I just want every one
to have the
same mental picture of what I am describing.) We approach the
wheel, which has
been dressed on its face, dead straight across with no
grooves..(Ve SHOOT anyone
ve catch putting grooves in ze drill wheel!!..No Pity..No
Prisoners..Ya!
Verdampt!)

(Sorry)...

The drill shank is held firmly in the RIGHT hand...ALL the
movement and control
is imparted by the RIGHT hand. For the purposes of drill grinding,
the left hand
could be...with benefit..a LUMP OF CLAY!!

It is from this "lump of clay" that we fashion the Bionic Darex".

Place your left hand thumb and finger tips LIGHTLY together..Relax
the other
three fingers aand let them naturally curl against the palm of
your hand. Let
the drill flute drop into the vee between thumb and fore finger
and let the tip
of the finger "Find" the curve of the flute where it fits
comfortably. The tip
of the thumb rests on the sharp junction ot the land and the
flute, about an
inch back from the drill tip.

Now...SQUEEZE HARD!!! YOUCH!...I said it would be easier if it
were clay! 8^)
Lift the drill from your fingers...see the GROOVE?...Drop the
drill back in..it
locates within a thou or two! Magic?..Bionic at least! Squeeze
again to set the
groove. You have created a customised drill guide that fits
better that that on
any machine ever built! You can relax your grip now..feel how
smoothly the
drill will ride back and forth, guided by the groove you have
created for it.

Place the knuckles of your left hand, LIGHTLY on the ginding wheel
tool rest,
and swing the drill shank, from left to right (using ONLY your
right hand) and
push the drill lengthways though that groove in your fingers back
or forth using
the groove to make the drill twist or "rifle" in your fingers. Do
NOT move your
left hand in any way..it is made of clay remember!

UNTIL....

A) The drill axis is "eyeballed" to be at half the required point
angle to the
wheel face...You can scribe or chalk reference lines on your
grinder benchtop to
help you line this up..at least untill it become almost second
nature.

B) The drill axis is dropped JUUUst below horizontal. This will
ensure that
your soon to be ground drill lip will start with a "smidgin" of
cutting
clearance.

(Ideally, and certainly for a beginner, the grinder rest should
be set dead
radially to the wheel center and about half the drill diameter
below the true
center of the wheel)

C) The two cutting edges of the drill..the straight, sharp bits,
formed by the
junction of the flute and the back face (the only bit you grind),
should be
horizontally disposed..with the edge uppermost on the side closest
to your left
hand..the othe sharp bit of course, pointing downwards (Jeeze
this would be a
lot easier with a sketch pad)

This I will call the SET or START position!

NOW, move your left hand for the first, last, and ONLY time during
th is whole
exercise. GENTLY ease the cutting edge towards the spinning
wheel, carefully
maintaining all the angles and orientations of the SET
position..until the
cutting edge is JUST shy of touching the wheel. If you listen
carefully you
will hear the tone of the entrained air, whistling through the
narrowing gap.
You will hear a subtle but distinct change of tone JUST, I mean
Just...a couple
tenths of a thou BEFORE the edge touches the wheel. STOP!!!
FREEZE!! DO NOT
MOVE!!

Now, press the knuckles of your lump of clay..sorry, your left
hand FIRMLY down
onto, into and around the grinding rest..establish a "Groove" on
the back of
your hand as well as between your fingers.

We are now ready to grind, Your left hand locked to the drill and
grinding rest
is otherwise quite relaxed..letting the drill slide, twist and
tilt wherever
your right hand and the groove in your fingers tell it to go.

The actual grinding is a bit of an anticlimax.

You have previously studied a new drill point, you have read about
clearance,
and cutting angles, and rakes and......

With the RIGHT hand in control, gently, kinda, lean forward...
bending or
squeezing your arms hands and body..rather than actually moving
them..untill you
take up that last couple of tenths and the wheel begins to cut.
Let it
cut..don't force it, and dont' rush it..it really won't hurt
anything if you
take a full minute Per pass per face. YOU and your "Bionic Darex"
are totally
in control of that drill and the wheel..Forget the times when,
close to panic,
you swung the drill wildly past the wheel, hoping to get "the
dirty deed" over
with as quickly as possible.

Take your time, enjoy the moment, THINK about the shape you are
trying to
generate. Just the one face is left to "Interpretation"...every
other
aspect,angle, facet, what have you...Has ALREADY BEEN TAKEN CARE
OF!! and is
locked in place under your control!

The right hand should perform a "Lower Quadrant sweep" for want
of a better
term..An observer behind you would see your hand move from about
17 minutes past
the hour on a clock face, to roughly 25 minutes past. But it
isn't a smooth arc
of a circle, more a sector of an elipse..You see, as your hand
starts to drop
slowly, you are also rotating the drill in "the groove"..the first
third of the
turn needs to maintain that very slight clearance angle on the
cutting edge, and
not increase it too rapidly.

You need the clearance to cut..But too much at that point will
WEAKEN the edge,
and cause the drill to snatch and chip...So the first part of the
rotation is
ALMOST but not quite, just as though you were grinding a straight
cone point on
the end of your drill. Only as you approach the second third,
does your right
hand start to noticably drop..kinda "Catching Up" on the rotary
motion...increasing the clearance as it does.

In the last third of the rotaion the right hand drops quite
rapidly..Thogh not
enough to catch the OTHER drill lip on the wheel..that lip is
coming around
quite rapidly by now.

Above all, take your time, if it helps, move the drill one degree
at a time, and
think ahead what shape or angle the next degree of cutting face
needs...Remember, you have control, and IT ain't going nowhere
'til you decide.

After a pass on one face, flip the drill in your "Bionic Darex"
DO NOT MOVE
THAT LEFT HAND!!, return to SET position and repeat, the pass on
the other face.

Having done a couple of passes on each face..it is now time to
check the results
on our homemade "Optical Comparator"

(Sorry Jim I couldn't resist!!) ;^)

Rest the center hole in back end of the drill shank, on the center
point of the
"Comparator" and use, first one and then the other drill lip to
scribe a light
line on your whitewashed (OK Blue or red dyed) surface.

You will readily see if the lines coincide..if the lips are
even..or not, as the
case may be.

Lets assume they are..Now look directly DOWN on the end of the
drill to check
the clearances. HUH? How can you check radial clearance by
looking it staight
in the face? Surely you need to look at it sideways?

Well no you don't...for once all thos interacting and confusing
angle and faces
and clearances are going to work together in YOUR favor and make
what could be a
tricky bit of metrology..quite simple. While we are looking at
the end of the
drill, we will also check that the POINT ANGLE is correct too!!!

(Ok guys, leave quietly..teenut has finally lost it!!)

No really, trust me. IF you look straight down on the point of a
well
sharpened, standard drill, you will see
the two cutting edges, joined by the CHISEL edge which crosses
over the web of
the drill The angle fromed by the chisel edge to each cutting
edge, should be
ABOUT 50 deg...anywhere between 40 and sixty is ok for a first
attempt. (I can
hear the purists and theorists screaming and lighting up their
flame throwers)
But believe me, get it in that ball park and your drill will CUT.
If the angle
is too steep..you don't have enough clearance...negative clearance
will give you
an angle event greater than 90 deg. Too MUCH clerance and the
angle will appear
too shallow!

While looking at the end, check the point angle, How? Look
down the axis of
the drill at the cutting edges. Are they straight? If so, your
point is pretty
close to the right angle (As designed for that drill, by its
manufacturer when
he set the helix angle and the cross section of the flute) If the
edges appear
CONCAVE the point is too flat and if they appear CONVEX, the point
is too
"Pointy"

If your drill passes all these tests, which take but a second or
two to perform,
THEN IT WILL CUT..pretty close to size, without chattering,
chipping,
overheating, wandering or seizing. I guarantee it!

Hey, thats a pretty good start for the first drill you ever
ground! All it
takes now is a bit of practice for it to become second nature and
almost as easy
with a little 'un or a big 'un!

Hey guys!

My apologies for "goin'on" but If it helps just one person to
pluck up the
couragre and go hand sharpen his (or Her) first drill, by hand...

Then I hope you will bear with me.

It is late, I am tired and I am not even going to proof or spell
check this,

'night all

teenut

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Raven" wrote in message
...
I use a great deal of drill bits in both metal and wood, and have
decided to try my hand at sharpening them. Is there a particular
angle for sharpening drills both for wood and metal. The largest
drill i ever use is 1/2 inch. A local hardware shop, sells a tool
that attaches to your smooth stone bench grider.

Any help is appreciated.

Peter

Sharpening drill bits on a wheel is a valuable skill. I learned it fifty
years ago when a summer job in a machine shop had me drilling all day long.
It is learned only by having someone show you. There are two important
angles and a twist of the wrist that requires patience. I can still sharpen
a drill although I have never done it "professionally" since the 50's.
Dave
"Raven" wrote in message
...
I use a great deal of drill bits in both metal and wood, and have decided
to try my hand at sharpening them. Is there a particular angle for
sharpening drills both for wood and metal. The largest drill i ever use is
1/2 inch. A local hardware shop, sells a tool that attaches to your smooth
stone bench grider.

Any help is appreciated.

Peter

On Thu, 06 Sep 2007 22:29:50 GMT, "Raven" wrote:

I use a great deal of drill bits in both metal and wood, and have decided to
try my hand at sharpening them. Is there a particular angle for sharpening
drills both for wood and metal. The largest drill i ever use is 1/2 inch. A
local hardware shop, sells a tool that attaches to your smooth stone bench
grider.

Any help is appreciated.

Peter

A neighbor sharpened all of my twist bits by hand on my grinding wheel...
claimed it was easy... *sigh*

He checked his angle by laying 2 hex nuts side by side with the flats touching,
and using the angle created on top or bottom to test his work.....

Very crude way to do it, but he sharpened almost 100 bits that morning and they
were damn sharp and cut well..

Thinking back, I'm pretty sure that he was using the side of the wheel, not the
face..


mac

Please remove splinters before emailing

In article ,
Raven wrote:
I use a great deal of drill bits in both metal and wood, and have decided to
try my hand at sharpening them. Is there a particular angle for sharpening
drills both for wood and metal. The largest drill i ever use is 1/2 inch. A
local hardware shop, sells a tool that attaches to your smooth stone bench
grider.

Any help is appreciated.

Peter



New metal cutting drill bits are generaly sold with a 118d to 120d included
angle. If you are resharpening these bits for use solely in wood, you can
use a steeper angle for faster cutting. I've seen the grinder attachments,
in fact I even have one squirreled away somewhere, but have never
used it (It was included in a box of junk I got at a flea market). With
some practice it is not too difficult to sharpen a larger
drill bit by hand to a useable condition. I don't bother with anything
smaller than 3/16" or so; When I was younger and my eyes were better I
resharpened smaller ones. Personally I can not sharpen a bit to an
edge as good as new but I have ssen people who can.


a factory-made cutting edge on a drill bit, but I have seen people
who can.


--
Make it as simple as possible, but no simpler.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

Raven wrote:
I use a great deal of drill bits in both metal and wood, and have decided to
try my hand at sharpening them. Is there a particular angle for sharpening
drills both for wood and metal. The largest drill i ever use is 1/2 inch. A
local hardware shop, sells a tool that attaches to your smooth stone bench
grider.

Any help is appreciated.

Peter


Peter, step outside, get some fresh air, drive to a good hardware store
and get a drill gage. The angle (one of the common ones) is stamped into
the gage and there are numbers along the angled face. Grind until
1) both cutting lips are at the same angle
2) the center of the chisel point is centered when measured against the gage
3) there is some relief angle down from the shank end of the cutting
lips. The relief angles should match.
4) you can not see a line at the cutting edge and looking at it along
the length of the shank reveals NO metal higher than the edge behind it.
If such an area exists, the drill will only rub, not cut.

You are done. Sharpen another.

It is a HUGE help if your grinding wheel is flat across the face and
round, but do not use the side of the wheel.

That's it. The angle on the purchased gage is set for mild steel and
will work 'well-enough' for many materials; other materials will benefit
from adjustments to this angle and the chip clearance relief. Larger
bits may benefit from web thinning (that's the chisel edge between the
cutting flutes) but first get this basic 'into your hands'. Below about
1/8", the difficulty involved in getting a good point argues in favor of
just buying them in jobber packs from J & L Machinery or Production Tool
or any of a number of other machine shop vendors.