I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!

Doug White

On 3/13/2013 19:32, Doug White wrote:
I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!

Doug White



Keyseat cutter. Square block , sticking above vise jaws, hole through
block horizontally. Set screw to lock.

--
Steve Walker
(remove brain when replying)

"Doug White" wrote in message
...
I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!

Doug White

You mount the rod into a collet and collet block like these
http://littlemachineshop.com/product...ProductID=3190

You use one edge of the block to locate your work piece
You cut a slot, rotate the block, 180 deg and cut the other slot.

Paul K. Dickman

"Doug White" wrote in message
...
...
Is that the only good way? Any other clever ideas? Any good excuse
to
buy a new tool?

Doug White

If you are looking for new toys you could consider a small toolmaker's
insert vise to clamp the part with both ends accessible.
http://www.travers.com/product.asp?r...084-61-410-050

The outside of the vise is precision ground to serve as reference
surfaces when you clamp it in a larger vise. They are especially handy
for milling at the precise angles you can set up with in an angle
block kit:
http://www.travers.com/product.asp?r=s&n=||UserSearch%3Dangle+block&eapro did=40600%2D57%2D020%2D224

jsw

"Paul K. Dickman" wrote in
:


"Doug White" wrote in message
...
I have a project that requires a machining operation that I am
puzzling
over. This particular piece doesn't require great precision, but I
would like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will
be counterbored about 1/8" deep to a diameter of 3/8". I want to
mill a flat bottomed groove 1/4" wide from the bottom of the
counterbore to the outside on both ends, and (here's the tricky part)
I want those two grooves aligned with each other as accurately as
possible. Basically, there will be a flat keyhole shaped pocket in
each end of the rod, and I want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the
rod sticking up vertically. The rod is too short to just flip the
block upside down and mill the opposite end with everything aligned.
If I take the rod out of the block, I lose the alignment, and the rod
is also short enough that I can't really easily reach into the back
side of the collet block with an indicator to align the groove.
Because the groove is only 1/8" long, I'm not going to get much
accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step,
and if I'm trying to learn here, kind of cheating. I can certainly
conceive of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could
probably do both ends with the rod clamped in a Vee block. I should
have a Vee block that is short enough to hold the rod with good
access to both ends without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse
to buy a new tool?

Thanks!

Doug White

You mount the rod into a collet and collet block like these
http://littlemachineshop.com/product...ProductID=3190

You use one edge of the block to locate your work piece
You cut a slot, rotate the block, 180 deg and cut the other slot.

I guess I wasn't clear enough. There is one slot on each end of the rod,
not two slots on one end. I have a collet block, which is fine for
cutting one end, but you have to remove the rod to cut the other end, and
then you have the problem of aligning the rod to the block so the slots
are at identical angles.

Doug White

"Jim Wilkins" wrote in
:

"Doug White" wrote in message
...
...
Is that the only good way? Any other clever ideas? Any good excuse
to
buy a new tool?

Doug White

If you are looking for new toys you could consider a small toolmaker's
insert vise to clamp the part with both ends accessible.
http://www.travers.com/product.asp?r...ol+Accessories
%7C%7CVises-Machine&eaprodid=80084-61-410-050

The outside of the vise is precision ground to serve as reference
surfaces when you clamp it in a larger vise. They are especially handy
for milling at the precise angles you can set up with in an angle
block kit:
http://www.travers.com/product.asp?r=s&n=||UserSearch%3Dangle+block&eap
rodid=40600%2D57%2D020%2D224

Thanks. I actually have the poor man's version, which is a small
Palmgren vise I trued up. That would work, but I think the Vee block is
still the winner.

Doug White

On Mar 13, 6:32*pm, Doug White wrote:
I have a project that requires a machining operation that I am puzzling
over. *This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. *Each end will be
counterbored about 1/8" deep to a diameter of 3/8". *I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. *Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. *The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. *If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. *Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. *I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. *I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? *Any other clever ideas? *Any good excuse to
buy a new tool?

Thanks!

Doug White

I'd put a 1/4" piece of keystock at the bottom of a milling machine
vise and flank it with two pieces of 3/16" keystock. Drop in the
workpiece in the vise with the 1/4" slot fitting in the middle
keystock. You should be able to clamp everything so that the
workpiece slot is parallel to the vise jaws. (Upside-down
screwdriver) Check for vertical perpendicularity with a machinist
square.

"Doug White" wrote in message
...
I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!



Put it in a vee block.

Clamp rod in vise small enough that the ends stick out past the jaws (or
clamp it down into a vee block to the table) with the long axis aligned with
the long dimension of the mill table, and cut across each end with a keyseat
cutter. No realignment or repositioning of the rod needed between cuts.

-----
Regards,
Carl Ijames
"Doug White" wrote in message
...

"Jim Wilkins" wrote in
:

"Doug White" wrote in message
...
...
Is that the only good way? Any other clever ideas? Any good excuse
to
buy a new tool?

Doug White

If you are looking for new toys you could consider a small toolmaker's
insert vise to clamp the part with both ends accessible.
http://www.travers.com/product.asp?r...ol+Accessories
%7C%7CVises-Machine&eaprodid=80084-61-410-050

The outside of the vise is precision ground to serve as reference
surfaces when you clamp it in a larger vise. They are especially handy
for milling at the precise angles you can set up with in an angle
block kit:
http://www.travers.com/product.asp?r=s&n=||UserSearch%3Dangle+block&eap
rodid=40600%2D57%2D020%2D224

Thanks. I actually have the poor man's version, which is a small
Palmgren vise I trued up. That would work, but I think the Vee block is
still the winner.

Doug White

Remember Al expands on heating - and you will be hearing as you
cut or mill on it - thereby cutting off or milling off more than you
plan. The metal will have to be flooded as you cut - to keep cool and
make the cut in the right place.

Al isn't all that easy to work with if you want a precision final.
It is for the most part and alloys easy enough to cut, but precision is
tough.

Martin

On 3/13/2013 6:32 PM, Doug White wrote:
I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!

Doug White

"Doug White" wrote in message
...
I have a project that requires a machining operation that I am puzzling
over. This particular piece doesn't require great precision, but I would
like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will be
counterbored about 1/8" deep to a diameter of 3/8". I want to mill a
flat bottomed groove 1/4" wide from the bottom of the counterbore to the
outside on both ends, and (here's the tricky part) I want those two
grooves aligned with each other as accurately as possible. Basically,
there will be a flat keyhole shaped pocket in each end of the rod, and I
want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the rod
sticking up vertically. The rod is too short to just flip the block
upside down and mill the opposite end with everything aligned. If I take
the rod out of the block, I lose the alignment, and the rod is also short
enough that I can't really easily reach into the back side of the collet
block with an indicator to align the groove. Because the groove is only
1/8" long, I'm not going to get much accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step, and
if I'm trying to learn here, kind of cheating. I can certainly conceive
of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could probably do
both ends with the rod clamped in a Vee block. I should have a Vee block
that is short enough to hold the rod with good access to both ends
without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse to
buy a new tool?

Thanks!

Doug White

How about using square or hex stock, then turn it round after you
make the groves.

Best Regards
Tom.
--
http://fija.org/

Steve Walker wrote in
:

On 3/13/2013 19:32, Doug White wrote:
I have a project that requires a machining operation that I am
puzzling over. This particular piece doesn't require great
precision, but I would like to learn and practice an accurate
approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will
be counterbored about 1/8" deep to a diameter of 3/8". I want to
mill a flat bottomed groove 1/4" wide from the bottom of the
counterbore to the outside on both ends, and (here's the tricky part)
I want those two grooves aligned with each other as accurately as
possible. Basically, there will be a flat keyhole shaped pocket in
each end of the rod, and I want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the
rod sticking up vertically. The rod is too short to just flip the
block upside down and mill the opposite end with everything aligned.
If I take the rod out of the block, I lose the alignment, and the rod
is also short enough that I can't really easily reach into the back
side of the collet block with an indicator to align the groove.
Because the groove is only 1/8" long, I'm not going to get much
accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step,
and if I'm trying to learn here, kind of cheating. I can certainly
conceive of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could
probably do both ends with the rod clamped in a Vee block. I should
have a Vee block that is short enough to hold the rod with good
access to both ends without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse
to buy a new tool?

Thanks!

Doug White

Keyseat cutter. Square block , sticking above vise jaws, hole through
block horizontally. Set screw to lock.

If I have the right sized keyseat cutter, that would also work with the
Vee block. I'll have to check my stash of cutters. It will have to be
samll enoungh in diameter to only cut one side of the rim of the
counterbore, but that could work.

Thanks.

Doug White

Martin Eastburn wrote in
:

Remember Al expands on heating - and you will be hearing as you
cut or mill on it - thereby cutting off or milling off more than you
plan. The metal will have to be flooded as you cut - to keep cool
and make the cut in the right place.

Al isn't all that easy to work with if you want a precision final.
It is for the most part and alloys easy enough to cut, but precision
is tough.

That's pretty much a general issue with holding tight tolerances in the
stuff. My big concern is not that the depth & width of the slot are
within a thousandth, but that the angle of the slots on each end is
within a degree or better.

I've typically used my collet block for working on round stuff this size,
but I should have a Vee block or small vise that will allow me to
reposition the work without losing my reference.

Using a keyslot cutter has the advantage that with appropriate clamping,
I don't have to move the workpiece at all.

Doug White

"azotic" wrote in
:


"Doug White" wrote in message
...
I have a project that requires a machining operation that I am
puzzling
over. This particular piece doesn't require great precision, but I
would like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will
be counterbored about 1/8" deep to a diameter of 3/8". I want to
mill a flat bottomed groove 1/4" wide from the bottom of the
counterbore to the outside on both ends, and (here's the tricky part)
I want those two grooves aligned with each other as accurately as
possible. Basically, there will be a flat keyhole shaped pocket in
each end of the rod, and I want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the
rod sticking up vertically. The rod is too short to just flip the
block upside down and mill the opposite end with everything aligned.
If I take the rod out of the block, I lose the alignment, and the rod
is also short enough that I can't really easily reach into the back
side of the collet block with an indicator to align the groove.
Because the groove is only 1/8" long, I'm not going to get much
accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step,
and if I'm trying to learn here, kind of cheating. I can certainly
conceive of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could
probably do both ends with the rod clamped in a Vee block. I should
have a Vee block that is short enough to hold the rod with good
access to both ends without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse
to buy a new tool?

Thanks!

Doug White

How about using square or hex stock, then turn it round after you
make the groves.

Ah! That would also work. Unnecessary in this case, but a possibility.
The trick would be turning it into a smooth cylinder with both ends
already finished. Flipping it around in a collet would invariably leave
a small step, although in this case, that's not critical.

Thanks to everyone for theri input. I'll return the group now to its
usually political wrangling....

Doug White

Do any metals contract, on heating?

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Martin Eastburn" wrote in message
...
Remember Al expands on heating - and you will be hearing as you
cut or mill on it - thereby cutting off or milling off more than you
plan. The metal will have to be flooded as you cut - to keep cool and
make the cut in the right place.

On Thu, 14 Mar 2013 09:38:40 -0400, "Stormin Mormon"
wrote:

Do any metals contract, on heating?

There are special formulations of Invar that have a slightly negative
thermal coefficient. The common grades used in industry are close to
zero.

--
Ed Huntress



Christopher A. Young
Learn more about Jesus
www.lds.org
.

"Martin Eastburn" wrote in message
...
Remember Al expands on heating - and you will be hearing as you
cut or mill on it - thereby cutting off or milling off more than you
plan. The metal will have to be flooded as you cut - to keep cool and
make the cut in the right place.

"Stormin Mormon" wrote in message
...

Do any metals contract, on heating?

Bizmuth expands on cooling.

On Thu, 14 Mar 2013 11:34:27 -0400, Ed Huntress
wrote:

On Thu, 14 Mar 2013 09:38:40 -0400, "Stormin Mormon"
wrote:

Do any metals contract, on heating?

There are special formulations of Invar that have a slightly negative
thermal coefficient. The common grades used in industry are close to
zero.

Negative up to about the Curie temperatu-
http://umpir.ump.edu.my/1208/1/Negat...romagnetic.PDF

Interesting that it's still negative down at liquid Nitrogen
temperatures.

On 14/03/13 13:38, Stormin Mormon wrote:
Do any metals contract, on heating?

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"Martin Eastburn" wrote in message
...
Remember Al expands on heating - and you will be hearing as you
cut or mill on it - thereby cutting off or milling off more than you
plan. The metal will have to be flooded as you cut - to keep cool and
make the cut in the right place.



I think you need to specify a temperature range in which you're
interested. IIRC Antimony expands slightly when it solidifies and that
feature is useful in getting better definition in some white metal
casting alloys like modern tin based pewter. Overall though it expands
on heating over the broader temperature range.

On Thu, 14 Mar 2013 02:32:50 GMT, Doug White
wrote:

"Paul K. Dickman" wrote in
:


"Doug White" wrote in message
...
I have a project that requires a machining operation that I am
puzzling
over. This particular piece doesn't require great precision, but I
would like to learn and practice an accurate approach to doing this.

I have an aluminum rod, 5/8" in diameter, and 3" long. Each end will
be counterbored about 1/8" deep to a diameter of 3/8". I want to
mill a flat bottomed groove 1/4" wide from the bottom of the
counterbore to the outside on both ends, and (here's the tricky part)
I want those two grooves aligned with each other as accurately as
possible. Basically, there will be a flat keyhole shaped pocket in
each end of the rod, and I want the two keyholes to be vertical.

I can easily mill the groove in one end using a collet block with the
rod sticking up vertically. The rod is too short to just flip the
block upside down and mill the opposite end with everything aligned.
If I take the rod out of the block, I lose the alignment, and the rod
is also short enough that I can't really easily reach into the back
side of the collet block with an indicator to align the groove.
Because the groove is only 1/8" long, I'm not going to get much
accuracy that way anyway.

I could mill a reference flat on the rod, but that's an extra step,
and if I'm trying to learn here, kind of cheating. I can certainly
conceive of applications where that wouldn't be kosher.

While writing this up, it suddenly occured to me that I could
probably do both ends with the rod clamped in a Vee block. I should
have a Vee block that is short enough to hold the rod with good
access to both ends without removing the rod between operations.

Is that the only good way? Any other clever ideas? Any good excuse
to buy a new tool?

Thanks!

Doug White

You mount the rod into a collet and collet block like these
http://littlemachineshop.com/product...ProductID=3190

You use one edge of the block to locate your work piece
You cut a slot, rotate the block, 180 deg and cut the other slot.

I guess I wasn't clear enough. There is one slot on each end of the rod,
not two slots on one end. I have a collet block, which is fine for
cutting one end, but you have to remove the rod to cut the other end, and
then you have the problem of aligning the rod to the block so the slots
are at identical angles.

Doug White

Id use a shaper and a V block with a flat to ref to.

Particularly if the rod is longer than the lift of my mill.

Gunner

The methodology of the left has always been:

1. Lie
2. Repeat the lie as many times as possible
3. Have as many people repeat the lie as often as possible
4. Eventually, the uninformed believe the lie
5. The lie will then be made into some form oflaw
6. Then everyone must conform to the lie