I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

The reason I have been thinking about this is because I did a shrink fit a
while back on a large ring on a tool (not a machine tool) for a friend a
couple months ago. It worked fine, and I didn't care if it was permanent
because the tool was beyond its intended life anyway. He's been using the
tool everyday in his business. Its on its second life.

Now my success with that lead me to think about a toy I picked up a while
back and the poor success I've had with tool holding with drill bits in a
regular jacobs style chuck on the lathe. Particular 1/2 shank stuff. The
toy is a turret for the tail stock. I'd have to go look, but I think the
sockets on the turret are 5/8. The pieces are just held in with a set
screw. Seems that anything you put in it would have to have a flat machined
on it to have any chance of not spinning.

Now here is where the shrink fit comes. I have a part I make periodically
that is quite simple and it makes a few dollars. I make up to a dozen at a
time. Ideally if I was making hundred at a time I'd send it out to be CNC
turned. Best practice is spot drill, pilot drill, drill, turn, part off,
flip, drill, and then bore. Thats a lot of drill changing One drill bit
is 1/2 inch, and one is 5/8. The part is aluminum, though so a sharp bit
isn't too likely to spin. Aluminum isn't all I turn though.

My thought at first was to make set screw holders for a variety of bits to
go in the turret. Then I'd have to grind flats on all the drills. Yuck.
Then I thought about shrink fit. Then I'd only have to grind flats on the
tool holders. Might be a bit dicey for a 1/2" shank drill in a 5/8 diameter
holder though. LOL.

Of course I wondered if I could easily get a good enough fit that way to
prevent a dull tool spinning in the shrink fit holder. I can soak the
holders at close to 600F on the BBQ grill pretty easy. That would provide
about .0025 expansion for a 0.500 hole in steel (apx), but for say a 1/4
hole 0.00125 (apx). I don't have a practical way to cool the tool much
lower than 0F, so that's not going to gain much. I guess 100 under ambient
most of the year is something, but on a small tool only about .00025. I'm
using the rough approximation of .001 /1"/100F. I know not all steels
shrink or grow the same.

Anyway, even if the whole shrink fit tool holder thing works. How do you
get a broke tool out of the holder? Its not really material cost. A short
piece of steel isn't all that expensive. Its the time to make it all. I
suppose for a drill, unless I break it, its not all that big of a deal.
When it gets dull I walk it over to the grinder, resharpen it, and pick up
the rotary tool to touch up the split point. Probably not a big deal on the
lathe since I'd mostly be using drills.

They do this for mills and drills and other things in relatively expensive
shank tool holders for milling as well. Are those tool holders considered
disposable?

On Tuesday, October 30, 2018 at 11:42:39 AM UTC-4, Bob La Londe wrote:
I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

The reason I have been thinking about this is because I did a shrink fit a
while back on a large ring on a tool (not a machine tool) for a friend a
couple months ago. It worked fine, and I didn't care if it was permanent
because the tool was beyond its intended life anyway. He's been using the
tool everyday in his business. Its on its second life.

Now my success with that lead me to think about a toy I picked up a while
back and the poor success I've had with tool holding with drill bits in a
regular jacobs style chuck on the lathe. Particular 1/2 shank stuff. The
toy is a turret for the tail stock. I'd have to go look, but I think the
sockets on the turret are 5/8. The pieces are just held in with a set
screw. Seems that anything you put in it would have to have a flat machined
on it to have any chance of not spinning.

Now here is where the shrink fit comes. I have a part I make periodically
that is quite simple and it makes a few dollars. I make up to a dozen at a
time. Ideally if I was making hundred at a time I'd send it out to be CNC
turned. Best practice is spot drill, pilot drill, drill, turn, part off,
flip, drill, and then bore. Thats a lot of drill changing One drill bit
is 1/2 inch, and one is 5/8. The part is aluminum, though so a sharp bit
isn't too likely to spin. Aluminum isn't all I turn though.

My thought at first was to make set screw holders for a variety of bits to
go in the turret. Then I'd have to grind flats on all the drills. Yuck.
Then I thought about shrink fit. Then I'd only have to grind flats on the
tool holders. Might be a bit dicey for a 1/2" shank drill in a 5/8 diameter
holder though. LOL.

Of course I wondered if I could easily get a good enough fit that way to
prevent a dull tool spinning in the shrink fit holder. I can soak the
holders at close to 600F on the BBQ grill pretty easy. That would provide
about .0025 expansion for a 0.500 hole in steel (apx), but for say a 1/4
hole 0.00125 (apx). I don't have a practical way to cool the tool much
lower than 0F, so that's not going to gain much. I guess 100 under ambient
most of the year is something, but on a small tool only about .00025. I'm
using the rough approximation of .001 /1"/100F. I know not all steels
shrink or grow the same.

Anyway, even if the whole shrink fit tool holder thing works. How do you
get a broke tool out of the holder? Its not really material cost. A short
piece of steel isn't all that expensive. Its the time to make it all. I
suppose for a drill, unless I break it, its not all that big of a deal.
When it gets dull I walk it over to the grinder, resharpen it, and pick up
the rotary tool to touch up the split point. Probably not a big deal on the
lathe since I'd mostly be using drills.

They do this for mills and drills and other things in relatively expensive
shank tool holders for milling as well. Are those tool holders considered
disposable?

I'm not sure I follow all of your question, but tools are easily removed from heat-shrink holders. I've even seen them *drop* out in demonstrations.

The better heat-shrink systems work quickly enough that the holder is expanded before the tool shank has much chance to expand. So, unless you wait too long, you have plenty of clearance to remove the tool before the shank heats up and expands.

--
Ed Huntress

wrote in message
...

On Tuesday, October 30, 2018 at 11:42:39 AM UTC-4, Bob La Londe wrote:
I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

The reason I have been thinking about this is because I did a shrink fit a
while back on a large ring on a tool (not a machine tool) for a friend a
couple months ago. It worked fine, and I didn't care if it was permanent
because the tool was beyond its intended life anyway. He's been using the
tool everyday in his business. Its on its second life.

Now my success with that lead me to think about a toy I picked up a while
back and the poor success I've had with tool holding with drill bits in a
regular jacobs style chuck on the lathe. Particular 1/2 shank stuff. The
toy is a turret for the tail stock. I'd have to go look, but I think the
sockets on the turret are 5/8. The pieces are just held in with a set
screw. Seems that anything you put in it would have to have a flat
machined
on it to have any chance of not spinning.

Now here is where the shrink fit comes. I have a part I make periodically
that is quite simple and it makes a few dollars. I make up to a dozen at
a
time. Ideally if I was making hundred at a time I'd send it out to be CNC
turned. Best practice is spot drill, pilot drill, drill, turn, part off,
flip, drill, and then bore. Thats a lot of drill changing One drill bit
is 1/2 inch, and one is 5/8. The part is aluminum, though so a sharp bit
isn't too likely to spin. Aluminum isn't all I turn though.

My thought at first was to make set screw holders for a variety of bits to
go in the turret. Then I'd have to grind flats on all the drills. Yuck.
Then I thought about shrink fit. Then I'd only have to grind flats on the
tool holders. Might be a bit dicey for a 1/2" shank drill in a 5/8
diameter
holder though. LOL.

Of course I wondered if I could easily get a good enough fit that way to
prevent a dull tool spinning in the shrink fit holder. I can soak the
holders at close to 600F on the BBQ grill pretty easy. That would provide
about .0025 expansion for a 0.500 hole in steel (apx), but for say a 1/4
hole 0.00125 (apx). I don't have a practical way to cool the tool much
lower than 0F, so that's not going to gain much. I guess 100 under
ambient
most of the year is something, but on a small tool only about .00025. I'm
using the rough approximation of .001 /1"/100F. I know not all steels
shrink or grow the same.

Anyway, even if the whole shrink fit tool holder thing works. How do you
get a broke tool out of the holder? Its not really material cost. A
short
piece of steel isn't all that expensive. Its the time to make it all. I
suppose for a drill, unless I break it, its not all that big of a deal.
When it gets dull I walk it over to the grinder, resharpen it, and pick up
the rotary tool to touch up the split point. Probably not a big deal on
the
lathe since I'd mostly be using drills.

They do this for mills and drills and other things in relatively expensive
shank tool holders for milling as well. Are those tool holders considered
disposable?

I'm not sure I follow all of your question, but tools are easily removed
from heat-shrink holders. I've even seen them *drop* out in demonstrations.

The better heat-shrink systems work quickly enough that the holder is
expanded before the tool shank has much chance to expand. So, unless you
wait too long, you have plenty of clearance to remove the tool before the
shank heats up and expands.

**********************
I was thinking maybe with induction heating instead of back yard BBQ grill
that might be the case.

On Tuesday, October 30, 2018 at 8:42:39 AM UTC-7, Bob La Londe wrote:
I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

A hybrid approach worked for me; we made our cutting-tips with a taper,
and pressed them into a tapered holder, but didn't use a locking taper (I think
we turned 4.5 degrees half-angle). The only trick is, we applied superglue
and pushed the tips in with a hydraulic press (known force, keeping our
eyes on the oil pressure gage).

This was in conjunction with an ultrasound drill (impact grinding); when the
tip wore, a sharp rap on its shank would remove it, and the holder
could be solvent-cleaned and ready for the next tip to be inserted.
On paper, it took about a ton of force to remove.

On Tue, 30 Oct 2018 08:42:35 -0700, "Bob La Londe"
wrote:

I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

You heat the tool holder up yet again and remove the tool and dispose
of it in the trash or in your used Carbide bucket for recycling.

Many shrink to fit tools are changed several times a day.

__

"Poor widdle Wudy...mentally ill, lies constantly, doesnt know who he is, or even what gender "he" is.

No more pathetic creature has ever walked the earth. But...he is locked into a mental hospital for the safety of the public.

Which is a very good thing."

Asun rauhassa, valmistaudun sotaan.


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On 2018-10-30, Bob La Londe wrote:
I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

By using a special induction heater to heat the holder quickly,
and get the tool out before it conducts enough heat from the holder to
lock up again at the higher temperature.

The reason I have been thinking about this is because I did a shrink fit a
while back on a large ring on a tool (not a machine tool) for a friend a
couple months ago. It worked fine, and I didn't care if it was permanent
because the tool was beyond its intended life anyway. He's been using the
tool everyday in his business. Its on its second life.

O.K.

Now my success with that lead me to think about a toy I picked up a while
back and the poor success I've had with tool holding with drill bits in a
regular jacobs style chuck on the lathe. Particular 1/2 shank stuff. The
toy is a turret for the tail stock. I'd have to go look, but I think the
sockets on the turret are 5/8. The pieces are just held in with a set
screw. Seems that anything you put in it would have to have a flat machined
on it to have any chance of not spinning.

Hmm ... my bed turret for my Clausing has a different way to
hold the tools (1" diameter in this case).

There are vertical holes drilled to partially intersect the
horizontal hole for the tool shank. You drop a stud into it which has a
')' milled into one side which is a continuation of the curve of the
tool shank hole. The top of the stud is threaded and fitted with a nut
and a washer. You slide the tool shank in, then tighten the nut which
locks the tool shank in firmly enough so it does not spin. (FWIW, the
turret has six stations, and automatic indexing from one station to the
next as the turret ram in retracted.

Now here is where the shrink fit comes. I have a part I make periodically
that is quite simple and it makes a few dollars. I make up to a dozen at a
time. Ideally if I was making hundred at a time I'd send it out to be CNC
turned. Best practice is spot drill, pilot drill, drill, turn, part off,
flip, drill, and then bore. That?s a lot of drill changing One drill bit
is 1/2 inch, and one is 5/8.

With the bed turret, you do all of the work on one end on a lot
of workpieces, letting the turret advance to the next tool as needed.
One station of the turret (as I use it) has both a depth stop and a
retracting center drill, so I save one station. I then drill and tap
under power (next time I'll probably do it with thread-forming taps so I
don't have to drill as deep to clear chips from a gun tap). That is two
more stations. Then a box tool to turn a set length to proper diameter,
and a Geometric die head to thread it, using the last two stations in
the turret.

Then the parting tool on the carriage is used to make relief at
the intersection of the thread with the shoulder, and then part it off,
using a turret carriage stop.

Obviously, this is for something specific, and a different
product would require a different setup.

The part is aluminum, though so a sharp bit
isn't too likely to spin. Aluminum isn't all I turn though.

My thought at first was to make set screw holders for a variety of bits to
go in the turret. Then I'd have to grind flats on all the drills. Yuck.
Then I thought about shrink fit. Then I'd only have to grind flats on the
tool holders. Might be a bit dicey for a 1/2" shank drill in a 5/8 diameter
holder though. LOL.

I need some diameter-reducing holders for some of the tools,
though most are 1" diameter. Mostly, I need the adaptors for smaller
Geometric die heads, which don't apply that much torque -- at least
working in brass as I normally do.

Of course I wondered if I could easily get a good enough fit that way to
prevent a dull tool spinning in the shrink fit holder. I can soak the
holders at close to 600F on the BBQ grill pretty easy. That would provide
about .0025 expansion for a 0.500 hole in steel (apx), but for say a 1/4
hole 0.00125 (apx). I don't have a practical way to cool the tool much
lower than 0F, so that's not going to gain much. I guess 100 under ambient
most of the year is something, but on a small tool only about .00025. I'm
using the rough approximation of .001 /1"/100F. I know not all steels
shrink or grow the same.

The tools are installed and removed from the holders using the
induction heating tool I mentioned. I don't have this, so I only know
of its existence, no direct experience with it.

Anyway, even if the whole shrink fit tool holder thing works. How do you
get a broke tool out of the holder?

The same way you are *supposed* to get it in -- with the quick
induction heating tool. It produces the heat in the holder only, so it
expands while the tool shank does not (at least not right away), so it
falls out or can be pushed out, depending.

Its not really material cost. A short
piece of steel isn't all that expensive. Its the time to make it all. I
suppose for a drill, unless I break it, its not all that big of a deal.
When it gets dull I walk it over to the grinder, resharpen it, and pick up
the rotary tool to touch up the split point. Probably not a big deal on the
lathe since I'd mostly be using drills.

Note that with these, the holders are designed to go into
automatic tool changers in CNC milling machines, so you also need to
record how far the end mill extends out of the holder, and enter this
information into the G-code program, so it produces the dimensions desired.

They do this for mills and drills and other things in relatively expensive
shank tool holders for milling as well. Are those tool holders considered
disposable?

Nope -- they just have one of the relatively expensive induction
heater to allow removal and replacement.

I don't think that a torch would heat the holder quickly enough
to prevent heat transfer to the tool shank so both expand at the same
rate.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) 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 ---

On Saturday, November 17, 2018 at 9:54:44 PM UTC-5, DoN. Nichols wrote:
On 2018-10-30, Bob La Londe wrote:
I've been wondering if shrink fit tool holders are single use.

You heat up the tool holder drop the tool in and let it cool. How do you
get the tool out when its worn out?

By using a special induction heater to heat the holder quickly,
and get the tool out before it conducts enough heat from the holder to
lock up again at the higher temperature.

The reason I have been thinking about this is because I did a shrink fit a
while back on a large ring on a tool (not a machine tool) for a friend a
couple months ago. It worked fine, and I didn't care if it was permanent
because the tool was beyond its intended life anyway. He's been using the
tool everyday in his business. Its on its second life.

O.K.

Now my success with that lead me to think about a toy I picked up a while
back and the poor success I've had with tool holding with drill bits in a
regular jacobs style chuck on the lathe. Particular 1/2 shank stuff. The
toy is a turret for the tail stock. I'd have to go look, but I think the
sockets on the turret are 5/8. The pieces are just held in with a set
screw. Seems that anything you put in it would have to have a flat machined
on it to have any chance of not spinning.

Hmm ... my bed turret for my Clausing has a different way to
hold the tools (1" diameter in this case).

There are vertical holes drilled to partially intersect the
horizontal hole for the tool shank. You drop a stud into it which has a
')' milled into one side which is a continuation of the curve of the
tool shank hole. The top of the stud is threaded and fitted with a nut
and a washer. You slide the tool shank in, then tighten the nut which
locks the tool shank in firmly enough so it does not spin. (FWIW, the
turret has six stations, and automatic indexing from one station to the
next as the turret ram in retracted.

Now here is where the shrink fit comes. I have a part I make periodically
that is quite simple and it makes a few dollars. I make up to a dozen at a
time. Ideally if I was making hundred at a time I'd send it out to be CNC
turned. Best practice is spot drill, pilot drill, drill, turn, part off,
flip, drill, and then bore. That?s a lot of drill changing One drill bit
is 1/2 inch, and one is 5/8.

With the bed turret, you do all of the work on one end on a lot
of workpieces, letting the turret advance to the next tool as needed.
One station of the turret (as I use it) has both a depth stop and a
retracting center drill, so I save one station. I then drill and tap
under power (next time I'll probably do it with thread-forming taps so I
don't have to drill as deep to clear chips from a gun tap). That is two
more stations. Then a box tool to turn a set length to proper diameter,
and a Geometric die head to thread it, using the last two stations in
the turret.

Then the parting tool on the carriage is used to make relief at
the intersection of the thread with the shoulder, and then part it off,
using a turret carriage stop.

Obviously, this is for something specific, and a different
product would require a different setup.

The part is aluminum, though so a sharp bit
isn't too likely to spin. Aluminum isn't all I turn though.

My thought at first was to make set screw holders for a variety of bits to
go in the turret. Then I'd have to grind flats on all the drills. Yuck.
Then I thought about shrink fit. Then I'd only have to grind flats on the
tool holders. Might be a bit dicey for a 1/2" shank drill in a 5/8 diameter
holder though. LOL.

I need some diameter-reducing holders for some of the tools,
though most are 1" diameter. Mostly, I need the adaptors for smaller
Geometric die heads, which don't apply that much torque -- at least
working in brass as I normally do.

Of course I wondered if I could easily get a good enough fit that way to
prevent a dull tool spinning in the shrink fit holder. I can soak the
holders at close to 600F on the BBQ grill pretty easy. That would provide
about .0025 expansion for a 0.500 hole in steel (apx), but for say a 1/4
hole 0.00125 (apx). I don't have a practical way to cool the tool much
lower than 0F, so that's not going to gain much. I guess 100 under ambient
most of the year is something, but on a small tool only about .00025. I'm
using the rough approximation of .001 /1"/100F. I know not all steels
shrink or grow the same.

The tools are installed and removed from the holders using the
induction heating tool I mentioned. I don't have this, so I only know
of its existence, no direct experience with it.

Anyway, even if the whole shrink fit tool holder thing works. How do you
get a broke tool out of the holder?

The same way you are *supposed* to get it in -- with the quick
induction heating tool. It produces the heat in the holder only, so it
expands while the tool shank does not (at least not right away), so it
falls out or can be pushed out, depending.

Its not really material cost. A short
piece of steel isn't all that expensive. Its the time to make it all. I
suppose for a drill, unless I break it, its not all that big of a deal.
When it gets dull I walk it over to the grinder, resharpen it, and pick up
the rotary tool to touch up the split point. Probably not a big deal on the
lathe since I'd mostly be using drills.

Note that with these, the holders are designed to go into
automatic tool changers in CNC milling machines, so you also need to
record how far the end mill extends out of the holder, and enter this
information into the G-code program, so it produces the dimensions desired.

They do this for mills and drills and other things in relatively expensive
shank tool holders for milling as well. Are those tool holders considered
disposable?

Nope -- they just have one of the relatively expensive induction
heater to allow removal and replacement.

I don't think that a torch would heat the holder quickly enough
to prevent heat transfer to the tool shank so both expand at the same
rate.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) 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 ---

One thing to keep in mind with shrink-fit systems is that nearly any of them, including the cheapest, work fine with carbide tool shanks, but only the better ones -- which heat faster than the cheaper ones -- work well with HSS shanks.

The thermal coefficient of expansion for tungsten carbide is much lower than for steel, making the speed of heating much less critical than it is for steel.

I've watched comparative tests with different brands on both types of tool shanks. As a minor aside, solid tungsten ("heavy metal") shanks, used on some boring tools and other deep-hole insert-type tools, behave like tungsten carbide in this regard.

--
Ed Huntress

On 18 Nov 2018 02:53:59 GMT, "DoN. Nichols"
wrote:

The tools are installed and removed from the holders using the
induction heating tool I mentioned. I don't have this, so I only know
of its existence, no direct experience with it.

I'm retired now but before my retirement, my partner Garett Churchill
and I manufactured and marketed small but powerful induction heaters
called the Roy. I did and still do to a certain extend, design all
the products. The highest power Roy was 5kW but there's a 10kW unit
sitting in my lab waiting on a round tuit.

At least for now, the Roy is retired too. I got tired of spending
every day in the lab!

I designed a smaller unit (about 1kW) for use by ammunition reloaders
to anneal the mouth of the cartridge before passing the case through
the forming die. It has a built-in timer (settable to 0.1 sec,
accurate to 1 microsecond) so the reloaded can get the same results
every time.

This heater which we call the Annie, should do your tool holder
heating just fine. I believe his price is still under $500. Contact
him at or go to http://www.fluxeon.com.

Meanwhile, feel free to ask me any induction heating-related technical
questions.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address

On Sun, 18 Nov 2018 20:46:51 -0500, Neon John wrote:

On 18 Nov 2018 02:53:59 GMT, "DoN. Nichols"
wrote:

The tools are installed and removed from the holders using the
induction heating tool I mentioned. I don't have this, so I only know
of its existence, no direct experience with it.

I'm retired now but before my retirement, my partner Garett Churchill
and I manufactured and marketed small but powerful induction heaters
called the Roy. I did and still do to a certain extend, design all
the products. The highest power Roy was 5kW but there's a 10kW unit
sitting in my lab waiting on a round tuit.

At least for now, the Roy is retired too. I got tired of spending
every day in the lab!

I designed a smaller unit (about 1kW) for use by ammunition reloaders
to anneal the mouth of the cartridge before passing the case through
the forming die. It has a built-in timer (settable to 0.1 sec,
accurate to 1 microsecond) so the reloaded can get the same results
every time.

If you have an "inexpensive" induction heater for cartridge
brass.... you can sell a gazillion of them.



This heater which we call the Annie, should do your tool holder
heating just fine. I believe his price is still under $500. Contact
him at or go to http://www.fluxeon.com.

Meanwhile, feel free to ask me any induction heating-related technical
questions.

John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address
__

"Poor widdle Wudy...mentally ill, lies constantly, doesnt know who he is, or even what gender "he" is.

No more pathetic creature has ever walked the earth. But...he is locked into a mental hospital for the safety of the public.

Which is a very good thing."

Asun rauhassa, valmistaudun sotaan.


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