I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125"
diameter,
0.400" length). I clamped the cylinder by the ends (faced-off and therefore
parallel) in a fairly substantial drill press vise, lined up the center and
center-drilled first. Then I tried drilling the hole with a new 135 degree
split
point drill. The whole assembly started shaking, squealing and in spite of
much
cutting oil a lot of smoke developed. The drill run at appx. 800 rpm ( a big
floor drill).

I made it through by gritting my teeth and closing my eyes. Afterward I
examined
the drill with a magnifying glass and found what I think are small pieces of
steel welded on.

An identical drill from the same vendor has no difficulty drilling into
steel
otherwise.

This is not the first time I have had a problem cross-drilling holes. The
clamping arrangements were different but the ensuing effects were pretty
much
the same.

I cannot understand why this is happening given the solid nature of clamping
and
all the other factors. I cannot see where flex would occur to produce the
extreme form of chatter and subsequent rubbing (which is surely where the
smoke
and welding effects come from).

It was suggested to me that the part gets distorted as the drilling
progresses. It is certainly possible however, the noise etc. starts almost
as soon as the drill hits the piece.

I has occured to me that drilling round stock is essentially an interrupted
cut until the drill has a chance to sink into the piece fully and engage the
flutes 360 degrees. In that case, however, I would have expected the noise
etc. to abate which did not happen. Perhaps by that time the drill is too
damaged?

What is it about drilling cross holes in small parts that causes these
things to happen?

I have tried different clamping arrangements in the past with essentially
the same result. I could not really see any other way to clamp this piece
differently considering its size and the size of the hole.

To solve this I can only think of drilling with progressively increasing
drill sizes (for 3/16" !!!?) or clamping the piece in a 4-jaw chuck and
drill it in a lathe.

Any other explanations or suggestions?

--
Michael Koblic
Campbell River, BC

Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125"
diameter,
0.400" length).

(...)

Any other explanations or suggestions?

I conjecture that the material is work hardening.
What would happen if you used a stub length drill,
pecked, and (importantly) used more feed pressure
on the quill?

Think Cole Drill Mode.

--Winston

Winston fired this volley in
:

What would happen if you used a stub length drill,
pecked, and (importantly) used more feed pressure
on the quill?

And... turn the drill clockwise! GGG

LLoyd

Lloyd E. Sponenburgh mentioned:
Winston fired this volley in
:

What would happen if you used a stub length drill,
pecked, and (importantly) used more feed pressure
on the quill?

And... turn the drill clockwise! GGG

LLoyd

*Clockwise* you say?

Thanks Lloyd, you may have saved me some time.

--Winston -- Counter-clockwise, south of the equator?

Lloyd E. Sponenburgh wrote:
Winston fired this volley in
:

What would happen if you used a stub length drill,
pecked, and (importantly) used more feed pressure
on the quill?

And... turn the drill clockwise! GGG


What direction is that? All my clocks are digital...

"Michael Koblic" fired this volley in
:

What direction is that? All my clocks are digital...


That's the opposite of Widdershins.

LLoyd

In article ,
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

"Michael Koblic" fired this volley in
:

What direction is that? All my clocks are digital...


That's the opposite of Widdershins.

Just go opposite of the NASCAR drivers.

"Michael Koblic" wrote:

What is it about drilling cross holes in small parts that causes these
things to happen?

How cheap are your drills? I tend to use PTD most of the time,

My other thought, are you using 'mystery metal' ?

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Wes wrote:
"Michael Koblic" wrote:

What is it about drilling cross holes in small parts that causes
these things to happen?

How cheap are your drills? I tend to use PTD most of the time,

My other thought, are you using 'mystery metal' ?


Cheap. But I thought even a cheap drill should last one hole - this was a
new drill! However, you may have a point: I have stub drills bought from KBC
Tools which I keep for the use with my Taig lathe. Nothing fancy, 118
degrees points. Cut way better than the Canadian Tire drills.

The metal should have been mild steel but I am beginning to wonder...I shall
re-run the procedure with a certified mild steel and a stub drill as Winston
suggested. I did peck and push...

--
Michael Koblic
Campbell River, BC

Michael Koblic wrote:
Wes wrote:
"Michael Koblic" wrote:

What is it about drilling cross holes in small parts that causes
these things to happen?
How cheap are your drills? I tend to use PTD most of the time,

My other thought, are you using 'mystery metal' ?


Cheap. But I thought even a cheap drill should last one hole - this was a
new drill! However, you may have a point: I have stub drills bought from KBC
Tools which I keep for the use with my Taig lathe. Nothing fancy, 118
degrees points. Cut way better than the Canadian Tire drills.

The metal should have been mild steel but I am beginning to wonder...I shall
re-run the procedure with a certified mild steel and a stub drill as Winston
suggested. I did peck and push...

We've all been in the situation where it becomes
clear that the cutting lips have turned into a 'bearing'.

Occasionally, one can rescue the situation
by applying more force to break through
the glasslike surface and the tool begins cutting
once again. It's that large pressure which allows
a Cole Drill to cut through stainless and tool steel
using regular HSS bits.

If you have sufficient force on the quill, the cutting
lips always stay below the work hardened area and it
never binds up (for that reason).

You might be surprised how much force you can put on the quill
with great results.

--Winston

Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125"
diameter,...

Ummm ... that leaves only a 1/16" "wall" to resist the clamping force.
Maybe the part is collapsing a touch & binding on the bit. Just a WAG.

Try this: clamp with the axis parallel to the vise jaws. 90 degrees to
what you're doing.

Bob

On 2009-09-22, Michael Koblic wrote:
I tried to drill a 3/16" cross-hole in a small steel cylinder (0.3125"
diameter,
0.400" length). I clamped the cylinder by the ends (faced-off and therefore
parallel) in a fairly substantial drill press vise, lined up the center and
center-drilled first. Then I tried drilling the hole with a new 135 degree
split
point drill. The whole assembly started shaking, squealing and in spite of
much
cutting oil a lot of smoke developed. The drill run at appx. 800 rpm ( a big
floor drill).

Hmm ... about 39 SFM. What was the material you are drilling?
And was it hardened steel or mild?

I made it through by gritting my teeth and closing my eyes. Afterward I
examined
the drill with a magnifying glass and found what I think are small pieces of
steel welded on.

Sounds like hardened steel.

An identical drill from the same vendor has no difficulty drilling into
steel
otherwise.

The *same* steel?

[ ... ]

I cannot understand why this is happening given the solid nature of clamping
and
all the other factors.

Note that the clamping may not be that solid. You are sure that
the ends of the cylinder are parallel -- but the jaws of the vise may
not be.

A quick-and-dirty way to get more grip is to put some cardboard
(not the corrugated stuff -- what used to come in shirts from the
laundry) between the workpiece and the moving jaw, leaving the fixed jaw
to define the position of the workpiece.

Oh yes -- and the 3/16" drill bit is quite flexible too. A
screw machine length drill bit would be shorter and thus less flexible.

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot see where flex would occur to produce the
extreme form of chatter and subsequent rubbing (which is surely where the
smoke
and welding effects come from).

Can you identify what was shaking relative to what? In a drill
press, there is flex in the column itself, the mounting of the table to
the column, the mounting of the vise to the table, and usually the fit
of the quill in the headstock casting.

Was the vise firmly bolted to the drill press table?

A milling machine is typically more rigid.

And some floor standing drill presses may as well be made of
freshly cooked noodles. :-)

It was suggested to me that the part gets distorted as the drilling
progresses. It is certainly possible however, the noise etc. starts almost
as soon as the drill hits the piece.

I has occured to me that drilling round stock is essentially an interrupted
cut until the drill has a chance to sink into the piece fully and engage the
flutes 360 degrees. In that case, however, I would have expected the noise
etc. to abate which did not happen. Perhaps by that time the drill is too
damaged?

Again -- what steel were you drilling? A hardened mystery metal
can be anything.

What is it about drilling cross holes in small parts that causes these
things to happen?

It doesn't -- for me. But I know what metal I am drilling.

I have tried different clamping arrangements in the past with essentially
the same result. I could not really see any other way to clamp this piece
differently considering its size and the size of the hole.

To solve this I can only think of drilling with progressively increasing
drill sizes (for 3/16" !!!?) or clamping the piece in a 4-jaw chuck and
drill it in a lathe.

Any other explanations or suggestions?

Find out what the metal is which you are trying to drill, and
how hardened it is. (How does a file do trying to cut it?) For some
exotic metals, you should talk to the drill makers to see what they
suggest.

Good Luck,
DoN.

--
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 ---

"DoN. Nichols" wrote in message
...

Hmm ... about 39 SFM. What was the material you are drilling?
And was it hardened steel or mild?

A mystery metal which I was probably wrongly lead to believe was mild steel.

An identical drill from the same vendor has no difficulty drilling into
steel
otherwise.

The *same* steel?

A different one.

I cannot understand why this is happening given the solid nature of
clamping
and
all the other factors.

Note that the clamping may not be that solid. You are sure that
the ends of the cylinder are parallel -- but the jaws of the vise may
not be.

A quick-and-dirty way to get more grip is to put some cardboard
(not the corrugated stuff -- what used to come in shirts from the
laundry) between the workpiece and the moving jaw, leaving the fixed jaw
to define the position of the workpiece.

Ah! That is useful...Thanks.

Oh yes -- and the 3/16" drill bit is quite flexible too. A
screw machine length drill bit would be shorter and thus less flexible.

Yes, that appears to be the consensus.

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot imagine that Canadian Tire sells anything but Chinese. They look
pretty though...

I cannot see where flex would occur to produce the
extreme form of chatter and subsequent rubbing (which is surely where the
smoke
and welding effects come from).

Can you identify what was shaking relative to what? In a drill
press, there is flex in the column itself, the mounting of the table to
the column, the mounting of the vise to the table, and usually the fit
of the quill in the headstock casting.

In the end everything was shaking including myself. It is worth noting that
I had a similar experience with a similar shape in my mini-mill but the
details are now obscure, especially the nature of the metal.

Was the vise firmly bolted to the drill press table?

I should remember but I do not. Somehow I think it was as I would normally
clamp this sort of work but I do not always bolt the vise for a
straightforward small hole. This, of course, was not it.

A milling machine is typically more rigid.

And some floor standing drill presses may as well be made of
freshly cooked noodles. :-)

It is what it is. Bridgeport it ain't.

snip

The experiment is to be repeated with some changes and bona fide mild steel.

--
Michael Koblic
Campbell River, BC

On Sep 24, 2:50*am, "Michael Koblic" wrote:
....
The experiment is to be repeated with some changes and bona fide mild steel.

--
Michael Koblic
Campbell River, BC

In my experience scrap-yard mystery metal and some hardware store CRS
machine considerably better after annealing. Often the quickie 'water
anneal' is enough; heat it red, quench when the glow disappears.

Milling or filing a flat makes cross-drilling easier, at least until
the bit breaks through and grabs. A few times I've used a center drill
beyond its intended depth to make a parallel-sided starting hole.

jsw

On 2009-09-24, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...

Hmm ... about 39 SFM. What was the material you are drilling?
And was it hardened steel or mild?

A mystery metal which I was probably wrongly lead to believe was mild steel.

BTW -- if you want a really nice steel to machine (as long as
you don't need to harden it), look for some 12L14 (very free turning
leaded mild steel, and it produces a beautiful finish.

An identical drill from the same vendor has no difficulty drilling into

[ ... ]

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot imagine that Canadian Tire sells anything but Chinese. They look
pretty though...

Pretty as in "gold colored". This means that they have been TiN
coated (Titanium Nitride, not the metal tin). If the surface appears to
be somewhat frosted under the coating, it is likely to be a very poor
metal. If the surface appears to have been polished before the TiN
coating, it is more likely to be a good steel -- which they took the
time to work with properly when fabricating the drill bit.

[ ... ]

Can you identify what was shaking relative to what? In a drill
press, there is flex in the column itself, the mounting of the table to
the column, the mounting of the vise to the table, and usually the fit
of the quill in the headstock casting.

In the end everything was shaking including myself.

Some things can be checked by touch. For example, with one
hand, touch one finger to the vise and another to the table. This makes
it fairly easy to tell if there is motion there. A similar test can
detect motion of the workpiece in the vise -- but be careful in case the
workpiece comes loose and starts spinning.

Also -- touch one finger to the headstock casting, and another
to the side of the quill to see if that is loose.

[ ... ]

A milling machine is typically more rigid.

And some floor standing drill presses may as well be made of
freshly cooked noodles. :-)

It is what it is. Bridgeport it ain't.

But something like a radial drill press is almost as rigid as a
Bridgeport -- but much larger and heavier.

[ ... ]

The experiment is to be repeated with some changes and bona fide mild steel.

Try 12L14 if you can get some. You will find it a true pleasure
to machine.

Enjoy,
DoN.

--
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 ---

"DoN. Nichols" wrote in message
...
On 2009-09-24, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...

Hmm ... about 39 SFM. What was the material you are drilling?
And was it hardened steel or mild?

A mystery metal which I was probably wrongly lead to believe was mild
steel.

BTW -- if you want a really nice steel to machine (as long as
you don't need to harden it), look for some 12L14 (very free turning
leaded mild steel, and it produces a beautiful finish.

A quick look tells me the local supplier carries only 1.5" diameter rods in
12L14. evryone sells them in various diameters and lengths for peanuts.
Including Amazon! But nobody ships to Canada. Some more local research is
called for.

More doughnuts..

An identical drill from the same vendor has no difficulty drilling into

[ ... ]

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot imagine that Canadian Tire sells anything but Chinese. They look
pretty though...

Pretty as in "gold colored". This means that they have been TiN
coated (Titanium Nitride, not the metal tin). If the surface appears to
be somewhat frosted under the coating, it is likely to be a very poor
metal. If the surface appears to have been polished before the TiN
coating, it is more likely to be a good steel -- which they took the
time to work with properly when fabricating the drill bit.

I kind of gathered they were TiN. however, to my untrained eye they look
shiny. I do not have anything high quality to compare - those are covered
with black oxide.

[ ... ]

Can you identify what was shaking relative to what? In a drill
press, there is flex in the column itself, the mounting of the table to
the column, the mounting of the vise to the table, and usually the fit
of the quill in the headstock casting.

In the end everything was shaking including myself.

Some things can be checked by touch. For example, with one
hand, touch one finger to the vise and another to the table. This makes
it fairly easy to tell if there is motion there. A similar test can
detect motion of the workpiece in the vise -- but be careful in case the
workpiece comes loose and starts spinning.

Also -- touch one finger to the headstock casting, and another
to the side of the quill to see if that is loose.

I will pay attention next time I run this test. I hope to eliminate this
kerfaffle with a clamping jig. Sounds like clamping by the ends and leaving
1/16" inch to support the hole is probably not a thing to do.

[ ... ]

A milling machine is typically more rigid.

And some floor standing drill presses may as well be made of
freshly cooked noodles. :-)

It is what it is. Bridgeport it ain't.

But something like a radial drill press is almost as rigid as a
Bridgeport -- but much larger and heavier.

Well, it ain't that either...:-)

[ ... ]

The experiment is to be repeated with some changes and bona fide mild
steel.

Try 12L14 if you can get some. You will find it a true pleasure
to machine.

There is a Zen-like quality to making steel wool on the Taig. When things go
badly elsewhere, I try and turn something on the Taig. Like a security
blanket. Funny, the mill does not have the same effect. I still experience a
child-like wonder when I center drill a rod and the hole is...in the center!

--
Michael Koblic
Campbell River, BC

On Fri, 25 Sep 2009 12:45:33 -0700, "Michael Koblic"
wrote:


A quick look tells me the local supplier carries only 1.5" diameter rods in
12L14. evryone sells them in various diameters and lengths for peanuts.
Including Amazon! But nobody ships to Canada. Some more local research is
called for.

More doughnuts..
Whatever you do, do not resort to using the 1"- bar from someone's
disused weight set. That is some of the worst machining material I
have ever encountered - worse even than re-bar from Mexico.
Gerry :-)}
London, Canada

On 2009-09-25, Michael Koblic wrote:

"DoN. Nichols" wrote in message

[ ... ]

BTW -- if you want a really nice steel to machine (as long as
you don't need to harden it), look for some 12L14 (very free turning
leaded mild steel, and it produces a beautiful finish.

A quick look tells me the local supplier carries only 1.5" diameter rods in
12L14. evryone sells them in various diameters and lengths for peanuts.
Including Amazon! But nobody ships to Canada. Some more local research is
called for.

Hmm ... 1.5" diameter is probably a pretty good size for some
projects -- especially lathe ones. You'll want to get as long a rod as
you can afford/(transport home) and have some way to cut it. The
typical 4x6" horizontal/vertical bandsaw works well for this. I've got
both 1-1/2" round 12L14 and whatever the hex size is which just barely
fits through the 1-3/8" spindle bore. Grips nicely in the 3-jaw chuck.

Of course, for smaller projects, having something closer to the
desired size is helpful -- in spite of a machinist friend at work who
always used to claim "the best metal is in the middle" as he took a 3"
chuck of round brass stock to make a 1/2" diameter part. Lots of chips. :-)

[ ... ]

And who made the drill bit? If Chinese, it is a pure guess as
to how good a steel is in the drill bit. If a US manufacturer like
Cleveland, you are going to be more certain of the quality of the steel,
and if you need it, you can go to a cobalt steel which is tougher (and
more expensive).

I cannot imagine that Canadian Tire sells anything but Chinese. They look
pretty though...

Pretty as in "gold colored". This means that they have been TiN
coated (Titanium Nitride, not the metal tin). If the surface appears to
be somewhat frosted under the coating, it is likely to be a very poor
metal. If the surface appears to have been polished before the TiN
coating, it is more likely to be a good steel -- which they took the
time to work with properly when fabricating the drill bit.

I kind of gathered they were TiN. however, to my untrained eye they look
shiny. I do not have anything high quality to compare - those are covered
with black oxide.

O.K. Yes the finish varies with the intended function. Black
oxide is nice for some materials, Polished parabolic flutes nicer for
others, TiN coated for letting the chips flow out from yet others. My
usual bits (the 118 piece set of number/letter/fractional and the cobalt
steel set of number-size screw machine length bits are both polished,
though not parabolic flute. The two sets which make up my stock of
metric sizes are black oxide, and I don't use them often enough to have
an opinion for my usual materials. My metric tap-and-drill set has
everything TiN coated, but Cleveland brand bits and taps, so I know that
they are good.

The 61-80 number sized set is polished -- if I examine them in a
microscope. Otherwise, they hard enough to even see. :-)

[ ... ]

Some things can be checked by touch. For example, with one
hand, touch one finger to the vise and another to the table. This makes
it fairly easy to tell if there is motion there. A similar test can
detect motion of the workpiece in the vise -- but be careful in case the
workpiece comes loose and starts spinning.

Also -- touch one finger to the headstock casting, and another
to the side of the quill to see if that is loose.

I will pay attention next time I run this test. I hope to eliminate this
kerfaffle with a clamping jig. Sounds like clamping by the ends and leaving
1/16" inch to support the hole is probably not a thing to do.

Was the workpiece hollow or solid metal? If solid, check
whether your drill press vise has a horizontal V-groove, ideally with a
Vertical one meeting it in the fixed jaw. These give a good grip, and
the vertical V-groove gives access to the area which you want to
cross-drill. (For that matter, you can take a short piece of material the
same diameter, face off the ends and drill through the center just the
size to accept the drill bit which you intend to use, and drop it down
the vertical V-groove after inserting the workpiece in the horizontal
V-groove. Then Tighten the vise and drill guided by the existing center
hole. (If you're going to drill a lot of holes like this, make the
guide out of drill rod, and harden it after machining (facing and
drilling), so it will last longer. Probably a good idea to use a
countersink to chamfer the hole at the upper end at least -- and
probably both ends so you don't have to worry about which end is up.

[ ... ]

The experiment is to be repeated with some changes and bona fide mild
steel.

Try 12L14 if you can get some. You will find it a true pleasure
to machine.

There is a Zen-like quality to making steel wool on the Taig. When things go
badly elsewhere, I try and turn something on the Taig. Like a security
blanket. Funny, the mill does not have the same effect. I still experience a
child-like wonder when I center drill a rod and the hole is...in the center!

What you want for the Zen quality is a small shaper -- say a 7"
one. You sit there watching the ram move in and out, with the workpiece
moving sideways just a little during each backstroke. And the tool is a
simple HSS lathe bit which you can grind as you wish.

Enjoy,
DoN.

--
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 ---