Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

Alvin in AZ

You want 3 flats on the shanks of drills so they don't slip/spin in a chuck
when in use?

I've done it freehand with a stone in a Dremel/rotary tool for some purposes
where accuracy wasn't critical. A file works well for knocking off a burr
from the shank that's been formed by slipping.

To use an indexing method to achieve the 120 degree spacing, something hex
shaped which can be secured to the drill can be used, turning the hex two
facets for each flat.
A drill chuck with chuck key holes can be used for somewhat accurate 120
degree indexing, using a pin or stop moved to each of the 3 chuck key holes
in the chuck body.
The issue then becomes utilizing a stop for the depth of the flats so they
turnout uniform.

A good practice is to tighten a chuck with a chuck key at all 3 positions to
get the best holding power of the chuck.

--
WB
..........


wrote in message ...
Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

Alvin in AZ

On Sat, 27 Apr 2013 04:33:12 +0000 (UTC), wrote:

Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

Alvin in AZ

Why?

And what kind of drill bits?

On 04/27/2013 12:53 AM, Wild_Bill wrote:

A good practice is to tighten a chuck with a chuck key at all 3
positions to get the best holding power of the chuck.

I can't remember where I discovered this (probably in this group), but
it is invaluable when running larger bits. You'd think it would be
something the manuals would want to include.

Jon

I don't recall if the shop class teachers of the '60s taught this, but I do
remember a tool salesman telling me this about 1980.
I thought he may have been making excuses for his tools, but it does reduce
drill slippage to almost nonexistent (even moreso now with lower quality
chucks being abundant).

--
WB
..........


"Jon Danniken" wrote in message
...
On 04/27/2013 12:53 AM, Wild_Bill wrote:

A good practice is to tighten a chuck with a chuck key at all 3
positions to get the best holding power of the chuck.

I can't remember where I discovered this (probably in this group), but it
is invaluable when running larger bits. You'd think it would be something
the manuals would want to include.

Jon

On Apr 26, 11:33*pm, wrote:
Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

Alvin in AZ

As a cheap index, you could drill through a hex nut and then slide the
nut onto the shank of the drill and epoxy it there. Once dried, use
it as an index and grind the flats using something like a table saw
with an abrasive wheel mounted in it. Pop off the nut when you're
done. You can weigh the drawbacks and dangers for yourself.

On Sat, 27 Apr 2013 04:33:12 +0000 (UTC), wrote:

Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD


get a collet block and 1/2 5C collet
http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3

then clamp in vice, file, rotate, repeat

karl

Alvin in AZ

On 2013-04-27, wrote:
Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

Pick up a collet block set (there are two forms -- square and
hex), and some 5C collets to fit the drill bits (just a 1/2" one
apparently). Clamp the bit in the collet with the shank sticking out,
put the collet block in a vise, and set up a pair of rollers made from
ball bearings on either side. The bearings will limit how far down a
file will cut. When one flat is cut as deep as the bearings will allow,
loosen the vise, rotate the block two flats and clamp it again in the
vise. This is a way to do it with no power tools, at least. This
should get all three flats the same depth, so the drill won't run off
center.

If your "grinding" includes a surface grinder (not likely with
the "basically no machinery" restriction, just the collet block, the
collet, and the mag chuck in the grinder should be all that is needed.

Good Luck,
DoN.

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DoN. Nichols wrote:
Pick up a collet block... (just a 1/2" one apparently).

Clamp the bit in the collet with the shank sticking out, put the
collet block in a vise, and set up a pair of rollers made from
ball bearings on either side. The bearings will limit how far
down a file will cut. When one flat is cut as deep as the
bearings will allow, loosen the vise, rotate the block two flats
and clamp it again in the vise. This is a way to do it with no
power tools, at least. This should get all three flats the same
depth, so the drill won't run off center.
DoN.

Cool.

Thanks DoN, Denis G. and Karl Townsend!
And everyone else that responded, trying to help.

Collet block or even a nut with a home drilled and tapped set screw
is the sort of technology I was looking for. Just needed some sort
of way to index it. Length and depth will be worked out later and
will definately look into the bearings as "file stops".

I believe the largest drill bit I have is 1" steped up in 1/16" and
some "fill-ins" that are 1/32" steps.

The Enco URL was especially useful with it's picture and all!

For the "other guys"...

As a kid I fiNgured out that tightening the drill check using all
the holes and going round and round from one hole to the next until
no more progress could be felt helped a lot. A kid kinda-has to with
weak "kid" hands.

But even now, sometimes the chuck needs a little more than that.
Some of the larger drill bits I've got have the three facets and
work great!

The German all steel keyless chuck I'm using grips the drill bits
pretty dangged good but the faceted bits, it grips better.

Thanks a lot guys!

Anybody got anything to add, fire away.

Alvin in AZ
ps- Been a long time since I was on a newsgroup, it's cool to see
familiar names like yours DoN. Karl Townsend too?

"Karl Townsend" wrote in message
...
On Sat, 27 Apr 2013 04:33:12 +0000 (UTC), wrote:

Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD


get a collet block and 1/2 5C collet
http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3

then clamp in vice, file, rotate, repeat

karl

Alvin in AZ

For indexing, get a spare chuck that takes a key you already have. A
chuck with a 3/8-24 mounting thread is useful to hold and grind small
parts if you mount it on a long bolt.

Chuck the drill bit in it backwards, insert both keys and clamp the
chuck in your bench vise with both keys resting on the vise jaws.
Grind the flat parallel to the tops of the jaws, the bench leg under
the vise, or some other convenient visual reference line. Repeat with
the keys in the other holes.

I tried this as far as running a file across the bit, parallel to the
jaw tops, but I'm not going to risk damage to a bit or file actually
cutting the three flats.

If you have a belt sander one key should be enough to keep the chuck
from rotating as you hold it on the table to sand in the flats. This
light and compact style of sander substitutes for both a bench grinder
and a larger belt sander for most of my home shop jobs:
http://www.woodworkingtalk.com/attac...5-img_0194.jpg

The platen behind the lower part of the belt lets you grind flat and
square, the unsupported area above is good for rounding off sharp ends
and edges. The version with a disk on the side may be better for
woodworkers but I prefer a larger horizontal belt sander (or a plane)
for smoothing sawn edges.

jsw

On Apr 27, 10:14*pm, "DoN. Nichols" wrote:
On 2013-04-27, wrote:

Got any tricks for a guy to evenly "Tri-cut" the butts of 1/2"
drill bits that basically has no machinery?

Draw filing, grinding whatever, don't care I mostly need a way
to index 'em.

What ideas you got popping out? xD

* * * * Pick up a collet block set (there are two forms -- square and
hex), and some 5C collets to fit the drill bits (just a 1/2" one
apparently). *Clamp the bit in the collet with the shank sticking out,
put the collet block in a vise, and set up a pair of rollers made from
ball bearings on either side. *The bearings will limit how far down a
file will cut. *When one flat is cut as deep as the bearings will allow,
loosen the vise, rotate the block two flats and clamp it again in the
vise. *This is a way to do it with no power tools, at least. *This
should get all three flats the same depth, so the drill won't run off
center.

* * * * If your "grinding" includes a surface grinder (not likely with
the "basically no machinery" restriction, just the collet block, the
collet, and the mag chuck in the grinder should be all that is needed.

* * * * Good Luck,
* * * * * * * * DoN.

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* * * * * (too) near Washington D.C. |http://www.d-and-d.com/dnichols/DoN.html
* * * * * *--- Black Holes are where God is dividing by zero ---

I like the idea of using the bearings to limit the depth of cut with a
file! Also liked Jim Wilkins' idea of using a spare keyed drill chuck
as an index.

IME, the shanks of HSS drills are typically soft enough to file without
damaging the file.
If the shanks weren't softer, they would be much more difficult to chuck
without slipping, and likely be a lot more instances of broken drills.

The results would be like chucking an endmill, which will work in some
instances, but is generally a bad practice since most drill chuck jaws
aren't treated with diamond dust for adequate gripping power of hard HSS.

--
WB
..........


"Jim Wilkins" wrote in message
...

For indexing, get a spare chuck that takes a key you already have. A chuck
with a 3/8-24 mounting thread is useful to hold and grind small parts if
you mount it on a long bolt.

Chuck the drill bit in it backwards, insert both keys and clamp the chuck
in your bench vise with both keys resting on the vise jaws. Grind the flat
parallel to the tops of the jaws, the bench leg under the vise, or some
other convenient visual reference line. Repeat with the keys in the other
holes.

I tried this as far as running a file across the bit, parallel to the jaw
tops, but I'm not going to risk damage to a bit or file actually cutting
the three flats.

If you have a belt sander one key should be enough to keep the chuck from
rotating as you hold it on the table to sand in the flats. This light and
compact style of sander substitutes for both a bench grinder and a larger
belt sander for most of my home shop jobs:
http://www.woodworkingtalk.com/attac...5-img_0194.jpg

The platen behind the lower part of the belt lets you grind flat and
square, the unsupported area above is good for rounding off sharp ends and
edges. The version with a disk on the side may be better for woodworkers
but I prefer a larger horizontal belt sander (or a plane) for smoothing
sawn edges.

jsw

Denis G. wrote:
I like the idea of using the bearings to limit the depth of cut
with a file! Also liked Jim Wilkins' idea of using a spare keyed
drill chuck as an index.

x2!

-All- the ideas have been helpful.

And Wild_Bill's got it right about drill-butts being
soft up to a certain spot too. (that spot varies

I got this but it's not square like yours is, JW...
http://www.panix.com/~alvinj/file12/beltsander.jpg

I "could" make something square tho, I think. xD

But I've been wanting a chopsaw for a long time...

Alvin in AZ

On Sat, 27 Apr 2013 09:55:16 -0400, "Wild_Bill"
wrote:

I don't recall if the shop class teachers of the '60s taught this, but I do
remember a tool salesman telling me this about 1980.
I thought he may have been making excuses for his tools, but it does reduce
drill slippage to almost nonexistent (even moreso now with lower quality
chucks being abundant).

Was taught this in the late 70's Vo Tech. However, the emphases was on three
jaw *lath* chucks, not drill chucks. Personal safety being more important than
preserving drill bit shanks.
--
William

On 2013-04-28, wrote:
DoN. Nichols wrote:
Pick up a collet block... (just a 1/2" one apparently).

Clamp the bit in the collet with the shank sticking out, put the
collet block in a vise, and set up a pair of rollers made from

[ ... bulk of my text snipped ... ]

Cool.

Thanks DoN, Denis G. and Karl Townsend!
And everyone else that responded, trying to help.

Collet block or even a nut with a home drilled and tapped set screw
is the sort of technology I was looking for. Just needed some sort
of way to index it. Length and depth will be worked out later and
will definately look into the bearings as "file stops".

I believe the largest drill bit I have is 1" steped up in 1/16" and
some "fill-ins" that are 1/32" steps.

O.K. So you need the full set of collets -- if using a collet
block.

[ ... ]

As a kid I fiNgured out that tightening the drill check using all
the holes and going round and round from one hole to the next until
no more progress could be felt helped a lot. A kid kinda-has to with
weak "kid" hands.

Been there. :-) Maybe as I get older, I'll be there again. :-(

But even now, sometimes the chuck needs a little more than that.
Some of the larger drill bits I've got have the three facets and
work great!

The German all steel keyless chuck I'm using grips the drill bits
pretty dangged good but the faceted bits, it grips better.

A Rohm (or is it "Rolhm"?) clone of an Albrecht chuck. Yes,
those are good -- and self tightening -- unless you are trying to use a
left-hand drill bit. :-)

[ ... ]

Alvin in AZ
ps- Been a long time since I was on a newsgroup, it's cool to see
familiar names like yours DoN. Karl Townsend too?

Welcome back! (And keep your killfile well tuned to get the
noise-to-signal ratio somewhat better. :-)

Good Luck,
DoN.

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On 2013-04-28, Wild_Bill wrote:
IME, the shanks of HSS drills are typically soft enough to file without
damaging the file.
If the shanks weren't softer, they would be much more difficult to chuck
without slipping, and likely be a lot more instances of broken drills.

Up to a point. Then you get to the import ones which are soft
all the way to the tip, and turn into reverse spirals the first time you
seriously attempt to use them. :-)

The results would be like chucking an endmill, which will work in some
instances, but is generally a bad practice since most drill chuck jaws
aren't treated with diamond dust for adequate gripping power of hard HSS.

With the exception of certain models of Albrecht drill chucks,
which do have the diamond grit for that very purpose. (There may be
others, but the Albrecht are the only ones I know of.)

Enjoy,
DoN.

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On 2013-04-29, William Bagwell wrote:
On Sat, 27 Apr 2013 09:55:16 -0400, "Wild_Bill"
wrote:

I don't recall if the shop class teachers of the '60s taught this, but I do
remember a tool salesman telling me this about 1980.
I thought he may have been making excuses for his tools, but it does reduce
drill slippage to almost nonexistent (even moreso now with lower quality
chucks being abundant).

Was taught this in the late 70's Vo Tech. However, the emphases was on three
jaw *lath* chucks, not drill chucks. Personal safety being more important than
preserving drill bit shanks.

With a tradeoff here. If you tighten on all three holes (for
chucks which *have* three holes -- some only have the single master key
hole), while you get a tighter grip, you are likely to get more runout
than if you tighten in the master key socket (usually marked with
something like a '0' stamped near it.)

Enjoy,
DoN.

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wrote in message
...
Denis G. wrote:

I got this but it's not square like yours is, JW...
http://www.panix.com/~alvinj/file12/beltsander.jpg

I "could" make something square tho, I think. xD

But I've been wanting a chopsaw for a long time...

Alvin in AZ

I wouldn't grind on the side of a chopsaw wheel. I had a misused
cutoff disk fly apart on my surface grinder, which is too heavy to
jump from the imbalance, but the fragments became shrapnel.

Perhaps you could mount the sander on a plank that supports a wooden
work table.
jsw

Jim Wilkins wrote:
I wouldn't grind on the side of a chopsaw wheel.

Yeah, it prob'ly wouldn't be stiff enough to work right anyway.
Mostly not thinking, just picturing how square they "look".

I had a misused cutoff disk fly apart on my surface grinder, which
is too heavy to jump from the imbalance, but the fragments became
shrapnel.
jsw

Yeah, it's not as fun as a carnival ride but just as exiting. LOL

What all did the pieces stick into and how deep did they go?

Little handgrinder cuttoff discs 4", 4+1/2", 5" fly apart all the time
but they're light weight and don't penetrate, just kinda hurt and spook
the heck outta ya! LOL

http://www.panix.com/~alvinj/file12/cutoffdisc.jpg

Alvin in AZ

DoN. Nichols wrote:
...need the full set of collets...

All of 'em have a 1/2" butt tho. xD

I don't have a 5/8" or bigger chuck. :/

Never found one at Kent's Tools in Tucson that had threads.

Kent needs to figure out a way to franchise his business.
His used tool store is the coolest store ever!

The German all steel keyless chuck I'm using grips the drill bits
pretty dangged good but the faceted bits, it grips better.

A Rohm clone of an Albrecht chuck. Yes, those are good -- and
self tightening -- unless you are trying to use a left-hand drill
bit. :-)

Yeah, that's the brand, wanted to post it but wasn't sure enough of
the name.

Alvin in AZ
ps- Been a long time since I was on a newsgroup, it's cool to see
familiar names like yours DoN. Karl Townsend too?

Welcome back! (And keep your killfile well tuned to get the
noise-to-signal ratio somewhat better. :-)
DoN.

Cool, thanks for the welcome back, DoN.

But.

"kill files are for sissies! " -Alvin in the 90's

YMMV? LOL

Butthead in AZ

wrote in message
...
Jim Wilkins wrote:

I had a misused cutoff disk fly apart on my surface grinder, which
is too heavy to jump from the imbalance, but the fragments became
shrapnel.
jsw

Yeah, it's not as fun as a carnival ride but just as exiting. LOL

What all did the pieces stick into and how deep did they go?

My surface grinder is reasonably well shielded to absorb such mayhem.
Once I was working near a surface grinder that the operator pushed too
hard, fragmenting the wheel. One large chunk thumped loudly into and
dented the steel door about 50' away. The rim velocity is ~60MPH. I
count myself lucky to not have more vivid tales of sharp flying
machine fragments, though I have been spattered with another
machinist's blood and finger parts.

It's informative to helplessly watch a piece of equipment shake loose
and fall off your motorcycle at that speed. I had a can of soda burst
like a grenade when it hit the asphalt below my boot.
jsw

Jim Wilkins wrote:
Once I was working near a surface grinder that the operator pushed
too hard, fragmenting the wheel. One large chunk thumped loudly
into and dented the steel door about 50' away. The rim velocity is
~60MPH.

Cool.

I showed up right after they hauled the guy away. He was on a track
welding gang that uses thermite to weld the rails together. A cable
driven hand grinder's gas engine's governer went haywire and he was
reaching over to kill it when the grinding wheel exploded. It broke
both forearm bones and just about cut his hand off.

It was a brown resinoid wheel, ~16 grit ~8"x 1".

I've seen them track welders using 8"x 1/8" grinding discs and
putting so much side pressure on 'em that the edge of the disc was
~3/4" out of line! 8-/ ...and they're just grinding away! LOL

There's a time limit. The dispatcher gives you the time between
trains and you have to decide if you can get the job done in that
much time.

-------------------

What's weird is the guy that got hurt was a brother to a buddy of
mine in my-department and was going there just to meet 'im.

Alvin in AZ
retired signlape

On Mon, 29 Apr 2013 12:49:46 -0400, "Jim Wilkins"
wrote:

I
count myself lucky to not have more vivid tales of sharp flying
machine fragments, though I have been spattered with another
machinist's blood and finger parts.

https://picasaweb.google.com/1040422...50026022501298

Gunner Asch wrote:
https://picasaweb.google.com/1040422...50026022501298

Oooo... I remember that.
I was hanging out here when that happened.

We had to wait a day or two for the picture.

Alvin in AZ

On 2013-04-29, wrote:
DoN. Nichols wrote:
...need the full set of collets...

All of 'em have a 1/2" butt tho. xD

I don't have a 5/8" or bigger chuck. :/

Yes -- but since you will want to be flatting the whole length
of the reduced shank, you will need to grip at the larger diameter, so
the full set of collets -- at least 1" down to 1/2" -- I guess that you
don't need the smaller ones.

Never found one at Kent's Tools in Tucson that had threads.

There is MSC (or other vendors) -- but not as affordable as your
"Kent's", likely.

[ ... ]

A Rohm clone of an Albrecht chuck. Yes, those are good -- and
self tightening -- unless you are trying to use a left-hand drill
bit. :-)

Yeah, that's the brand, wanted to post it but wasn't sure enough of
the name.

While I posted with two spellings -- one of which *may* be
right. :-)

Enjoy,
DoN.

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I've never tried it and wouldn't consider it a good practice, but.. using a
small strip of silicon carbide wet-or-dry paper around a drill shank may
improve the chuck's grip in a moment of desperation.

Cleaning any abrasive dust from the chuck afterward may prevent any
detrimental effects.
For an old, worn chuck, a smear of valve grinding paste on the drill shank
may save the day, in a MacGyver emergency situation.

The SC paper gripping method works well in vises for gripping hard surface
workpieces.

Shirley Someone has tried this one time.

--
WB
..........


"DoN. Nichols" wrote in message
...
On 2013-04-28, Wild_Bill wrote:
IME, the shanks of HSS drills are typically soft enough to file without
damaging the file.
If the shanks weren't softer, they would be much more difficult to chuck
without slipping, and likely be a lot more instances of broken drills.

Up to a point. Then you get to the import ones which are soft
all the way to the tip, and turn into reverse spirals the first time you
seriously attempt to use them. :-)

The results would be like chucking an endmill, which will work in some
instances, but is generally a bad practice since most drill chuck jaws
aren't treated with diamond dust for adequate gripping power of hard HSS.

With the exception of certain models of Albrecht drill chucks,
which do have the diamond grit for that very purpose. (There may be
others, but the Albrecht are the only ones I know of.)

Enjoy,
DoN.

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Wild_Bill wrote:
I've never tried it and wouldn't consider it a good practice,
but.. using a small strip of silicon carbide wet-or-dry paper
around a drill shank may improve the chuck's grip in a moment
of desperation.
...
The SiC paper gripping method works well in vises for gripping
hard surface workpieces.

Shirley Someone has tried this one time.
WB

This Shirley hasn't tried it yet but will be pretty dangged soon. xD

Surely in AZ