On Tue, 19 Aug 2008 15:51:29 -0400, "Joe AutoDrill"
wrote:

I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they have
been trilling this material they call "Torlon PEI" with a. 0.029" drill at
around 10,000 RPM

The material is 3/8" thick and they have no problems making the hole itself.
I thought they would have to peck drill it, but apparently not...

The drill rapids up to the surface, takes a controlled feed rate from 1/16"
prior to the end of stroke (clean through) and retracts at rapid speed.
Much like a CNC would but with a simple, but highly controllable hydraulic
feed control doing the dirty work.

Now that every penny counts more, they found that the process leaves a burr
on the product that they have been removing since day #1 by hand. They want
to try and drill without getting that burr..

Here's the kicker... The burr is at the entry side, not the break through
side...

My first thought was that they were controlling the feed rate too late and
that the drill was entering the material fast, then slowing down and
completing the stroke. They claim that is not the case and that the feed is
100% controlled from entry to breakthrough. They also claim that the burr
shows up when entry happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might be causing
the problem?

RPM or other suggestions, thoughts? Etc... Can't really go above around
11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit but
they are using a drill bushing to make sure accuracy is held very tight.
Can't use a drill bushing in that case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **
Greetings Joe,
Since a drill bushing is being used how about grinding the end of the
drill bushing so that there is virtually no edge break, maybe .002",
on the exit end of the bushing. Then have the bushing contact the work
during the drilling process, or at least during the beginning, which
is when they say the burr is being formed. It seems to me that since a
drill bushing is being used for accuracy it must already be so close
to the work that the chips are going through the bushing. If this is
the case then having the bushing contact the work during the complete
drilling process would be fine and would prevent a burr from forming
at any time. I of course don't know what the setup looks like but
maybe a spring loaded drill bushing mounted in a ground sleeve would
make it easy to insure the bushing always contacted the work. The fit
between the bushing and sleeve could be kept to no more than .0002" so
accuracy would not suffer considering the holes are in plastic. If
space is limited belleville springs could be used.
Cheers,
Eric

I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they have
been trilling this material they call "Torlon PEI" with a. 0.029" drill at
around 10,000 RPM

The material is 3/8" thick and they have no problems making the hole itself.
I thought they would have to peck drill it, but apparently not...

The drill rapids up to the surface, takes a controlled feed rate from 1/16"
prior to the end of stroke (clean through) and retracts at rapid speed.
Much like a CNC would but with a simple, but highly controllable hydraulic
feed control doing the dirty work.

Now that every penny counts more, they found that the process leaves a burr
on the product that they have been removing since day #1 by hand. They want
to try and drill without getting that burr..

Here's the kicker... The burr is at the entry side, not the break through
side...

My first thought was that they were controlling the feed rate too late and
that the drill was entering the material fast, then slowing down and
completing the stroke. They claim that is not the case and that the feed is
100% controlled from entry to breakthrough. They also claim that the burr
shows up when entry happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might be causing
the problem?

RPM or other suggestions, thoughts? Etc... Can't really go above around
11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit but
they are using a drill bushing to make sure accuracy is held very tight.
Can't use a drill bushing in that case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **

"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they
have been trilling this material they call "Torlon PEI" with a. 0.029"
drill at around 10,000 RPM

The material is 3/8" thick and they have no problems making the hole
itself. I thought they would have to peck drill it, but apparently not...

The drill rapids up to the surface, takes a controlled feed rate from
1/16" prior to the end of stroke (clean through) and retracts at rapid
speed. Much like a CNC would but with a simple, but highly controllable
hydraulic feed control doing the dirty work.

Now that every penny counts more, they found that the process leaves a
burr on the product that they have been removing since day #1 by hand.
They want to try and drill without getting that burr..

Here's the kicker... The burr is at the entry side, not the break through
side...

My first thought was that they were controlling the feed rate too late and
that the drill was entering the material fast, then slowing down and
completing the stroke. They claim that is not the case and that the feed
is 100% controlled from entry to breakthrough. They also claim that the
burr shows up when entry happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might be causing
the problem?

RPM or other suggestions, thoughts? Etc... Can't really go above around
11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit but
they are using a drill bushing to make sure accuracy is held very tight.
Can't use a drill bushing in that case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **

We drill and tap holes in polycarb (which is a little on the gummy side),
maybe 1000 holes per lot, Dia.3/64 thru .125 thick, tap drill for 0-80
Flood coolant, hocut 795cu 5% in tap water

Maybe 6krpm, I dunno about the feedrate,I'd guess something approprite for
aluminum, using hss screw machine drills, garden variety, virgin new.

I've never noticed the entry burr your cutomer describes, maybe I'm not
picky enough =)

I've never noticed the entry burr your cutomer describes, maybe I'm not
picky enough =)

They can't tell me the size of the burr. could be that it is a medical
application and *any* burr is too much...
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **

Joe AutoDrill wrote:


Here's the kicker... The burr is at the entry side, not the break
through side...

It isn't really a burr Joe.
They are melting the material when the drill enters and you have a slight
bulge.
Have them look at their "burr" under a microscope.


RPM or other suggestions, thoughts? Etc... Can't really go above
around 11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit
but they are using a drill bushing to make sure accuracy is held very
tight. Can't use a drill bushing in that case...

Make up a drill with two diameters - .008" for .03 and then the full
diameter.
The Torlon will flow and set again before the larger diameter catches it and
what has "flowed" outward from the point will be removed cleanly.

Also, use a 142 degree point geometry.

Lastly, advice is worth what you pay for it and sometimes not even that!
LOL



Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **

--

John R. Carroll
www.machiningsolution.com

Here's the kicker... The burr is at the entry side, not the break
through side...

It isn't really a burr Joe.
They are melting the material when the drill enters and you have a slight
bulge.
Have them look at their "burr" under a microscope.

It could possibly be eliminated with a lower RPM then... Slower RPM,
slower feed. Less heat. Maybe...

RPM or other suggestions, thoughts? Etc... Can't really go above
around 11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit
but they are using a drill bushing to make sure accuracy is held very
tight. Can't use a drill bushing in that case...

Make up a drill with two diameters - .008" for .03 and then the full
diameter.
The Torlon will flow and set again before the larger diameter catches it
and
what has "flowed" outward from the point will be removed cleanly.

Also, use a 142 degree point geometry.

I think they like their standard tooling, but will suggest it as a "try
this" option.

Lastly, advice is worth what you pay for it and sometimes not even that!
LOL

$14.95 a month for DSL.

Thanks for the thoughts. I'll compile the responses from here and some
other forums and send them a list of suggestions to try. This one is at the
top of the list.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **

"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they
have been trilling this material they call "Torlon PEI" with a. 0.029"
drill at around 10,000 RPM

The material is 3/8" thick and they have no problems making the hole
itself. I thought they would have to peck drill it, but apparently not...

The drill rapids up to the surface, takes a controlled feed rate from
1/16" prior to the end of stroke (clean through) and retracts at rapid
speed. Much like a CNC would but with a simple, but highly controllable
hydraulic feed control doing the dirty work.

Now that every penny counts more, they found that the process leaves a
burr on the product that they have been removing since day #1 by hand.
They want to try and drill without getting that burr..

Here's the kicker... The burr is at the entry side, not the break through
side...

My first thought was that they were controlling the feed rate too late and
that the drill was entering the material fast, then slowing down and
completing the stroke. They claim that is not the case and that the feed
is 100% controlled from entry to breakthrough. They also claim that the
burr shows up when entry happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might be causing
the problem?

RPM or other suggestions, thoughts? Etc... Can't really go above around
11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit but
they are using a drill bushing to make sure accuracy is held very tight.
Can't use a drill bushing in that case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **

Certain plastic brush blocks do that. Can you put a collar on the drill
that will cut away the offence? Too bad it's so small, 1/4" would be
easier!

For purposes of determining the problem, can they stop the
drill short, say 1x drill dia deep? If so, give it a shot
and see if the burr is still there. I'm wondering if at 10k
rpm, the chip coming out of the hole might not be rubbing,
melting and displacing some of the material.

The short peck wouldn't leave a burr unless John C. is
right. Not saying he's not, just trying to offer an
alternate thought.

Jon

Have the hole counter sinked - or have a drill guild drill and that might
take off the bur. special drill and change. Then the fast one inside.

Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Joe AutoDrill wrote:
I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they have
been trilling this material they call "Torlon PEI" with a. 0.029" drill at
around 10,000 RPM

The material is 3/8" thick and they have no problems making the hole itself.
I thought they would have to peck drill it, but apparently not...

The drill rapids up to the surface, takes a controlled feed rate from 1/16"
prior to the end of stroke (clean through) and retracts at rapid speed.
Much like a CNC would but with a simple, but highly controllable hydraulic
feed control doing the dirty work.

Now that every penny counts more, they found that the process leaves a burr
on the product that they have been removing since day #1 by hand. They want
to try and drill without getting that burr..

Here's the kicker... The burr is at the entry side, not the break through
side...

My first thought was that they were controlling the feed rate too late and
that the drill was entering the material fast, then slowing down and
completing the stroke. They claim that is not the case and that the feed is
100% controlled from entry to breakthrough. They also claim that the burr
shows up when entry happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might be causing
the problem?

RPM or other suggestions, thoughts? Etc... Can't really go above around
11-12,000 RPM on this application due to machine limitations.

My next suggestion to them was to try and get a small countersink bit but
they are using a drill bushing to make sure accuracy is held very tight.
Can't use a drill bushing in that case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **


----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= - Total Privacy via Encryption =---

"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they have
been trilling this material they call "Torlon PEI" with a. 0.029" drill at
around 10,000 RPM

The other answer is a brad and spur drill tip. I use these for wood. I can get
them made for you.

"Jon Anderson" wrote in message
. ..
For purposes of determining the problem, can they stop the drill short,
say 1x drill dia deep? If so, give it a shot and see if the burr is still
there. I'm wondering if at 10k rpm, the chip coming out of the hole might
not be rubbing, melting and displacing some of the material.

The short peck wouldn't leave a burr unless John C. is right. Not saying
he's not, just trying to offer an alternate thought.

They could do a one-time peck... A trial per say... But the drill itself
is not set up for peck drilling. It's a limited use machien we sell when a
customer needs high RPM or has a space constraint for the machine.

Might help diagnose the problem, but not necessarily solve it for them...

--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **

I have a customer who bought a machine back in '05. Since day #1, they
have been trilling this material they call "Torlon PEI" with a. 0.029"
drill at around 10,000 RPM

The other answer is a brad and spur drill tip. I use these for wood. I
can get them made for you.

They make 'em that small? Might be a consideration for them...
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **

On Wed, 20 Aug 2008 03:53:45 -0400, with neither quill nor qualm, "Tom
Gardner" quickly quoth:


"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert incognito.

I have a customer who bought a machine back in '05. Since day #1, they have
been trilling this material they call "Torlon PEI" with a. 0.029" drill at
around 10,000 RPM

The other answer is a brad and spur drill tip. I use these for wood. I can get
them made for you.

Yeah, both forstner and brad-point billdrits should work just fine for
slow-speed drilling on most plastics. I used to use standard twist
bits in my air drill when I was cutting holes in plastic truck
dashboards for a living. It would half melt/half cut the square holes
for A/C ducts. I sure do NOT miss that summer in Phoenix, AZ...

--
It is pretty hard to tell what does bring happiness;
poverty and wealth have both failed.
-- Kin Hubbard

Yeah, both forstner and brad-point billdrits should work just fine for
slow-speed drilling on most plastics. I used to use standard twist
bits in my air drill when I was cutting holes in plastic truck
dashboards for a living. It would half melt/half cut the square holes
for A/C ducts. I sure do NOT miss that summer in Phoenix, AZ...

Phoenix? Plastic? Melting? Did you even need to spin the drill or did it
just have to sit in the sun and then get hand pushed through? grin

I drove through Tucson and Pheonix last August... In a black SUV... All I
can say is Buster Poindexter was right! Hot! Hot! Hot!

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **

I agree that the burr may be from melting. If so, a magnifier will show
a smooth outer edge.

If so, we use a razor blade to "cut" it off. -Still pretty time consuming.

Could they use a short (automatic) blast of air during the start of the
drilling to stop the melting (if, indeed, melting is occurring).

Not the incognito plastics expert,
Pete Stanaitis
--------------------

Probably this answer is more in the category of "misc. ramblings", but
could you use cooling from a stream of gas (CO2 or liquid N2) to cool
the plastic. Maybe you could get it to behave more "crystaline".
Alternatively, maybe you could add the same sort of cooling with
passages in the drill guide fixture.
Not sure about the economics of all this and you might make other
problems with condensing water on the drill guide fixture, etc., but
the plastic might behave better when cold.

"Joe AutoDrill" wrote in message
...
I have a customer who bought a machine back in '05. Since day #1, they
have been trilling this material they call "Torlon PEI" with a. 0.029"
drill at around 10,000 RPM

The other answer is a brad and spur drill tip. I use these for wood. I
can get them made for you.

They make 'em that small? Might be a consideration for them...


Sorry, my supplier said no, .100 is the smallest they go. I did give him
your info, they might call you in the future. They are a brush machine
builder.

"Denis G." wrote in message
...
Probably this answer is more in the category of "misc. ramblings", but
could you use cooling from a stream of gas (CO2 or liquid N2) to cool
the plastic. Maybe you could get it to behave more "crystaline".
Alternatively, maybe you could add the same sort of cooling with
passages in the drill guide fixture.
Not sure about the economics of all this and you might make other
problems with condensing water on the drill guide fixture, etc., but
the plastic might behave better when cold.

Nice out-of-box thinking!

On Wed, 20 Aug 2008 11:30:26 -0700 (PDT), "Denis G."
wrote:

Probably this answer is more in the category of "misc. ramblings", but
could you use cooling from a stream of gas (CO2 or liquid N2) to cool
the plastic.

Or this:
http://www.vortec.com/cold_air_guns.php

--
Ned Simmons

Joe AutoDrill wrote:

They could do a one-time peck... A trial per say... But the drill itself
is not set up for peck drilling. It's a limited use machien we sell when a
customer needs high RPM or has a space constraint for the machine.

Might help diagnose the problem, but not necessarily solve it for them...

That was all I had in mind.

Jon

Joe, I get really clean holes in plastic with a Unibit. I know
they can't use the normal Unibit, but you might try duplicating
the single flute and angle geometry of the bit.

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




"Joe AutoDrill" wrote in message
...
I'm posting this here in case we have a plastic expert
incognito.

I have a customer who bought a machine back in '05. Since day
#1, they have been trilling this material they call "Torlon PEI"
with a. 0.029" drill at around 10,000 RPM

The material is 3/8" thick and they have no problems making the
hole itself. I thought they would have to peck drill it, but
apparently not...

The drill rapids up to the surface, takes a controlled feed rate
from 1/16" prior to the end of stroke (clean through) and
retracts at rapid speed. Much like a CNC would but with a
simple, but highly controllable hydraulic feed control doing the
dirty work.

Now that every penny counts more, they found that the process
leaves a burr on the product that they have been removing since
day #1 by hand. They want to try and drill without getting that
burr..

Here's the kicker... The burr is at the entry side, not the
break through side...

My first thought was that they were controlling the feed rate
too late and that the drill was entering the material fast, then
slowing down and completing the stroke. They claim that is not
the case and that the feed is 100% controlled from entry to
breakthrough. They also claim that the burr shows up when entry
happens and not during the process.

Anyone have any tips, thoughts or misc. ramblings on what might
be causing the problem?

RPM or other suggestions, thoughts? Etc... Can't really go
above around 11-12,000 RPM on this application due to machine
limitations.

My next suggestion to them was to try and get a small
countersink bit but they are using a drill bushing to make sure
accuracy is held very tight. Can't use a drill bushing in that
case...

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


** Posted from http://www.teranews.com **

I ran a job kinda like this for a medical research lab. 1/2" delrin,
3"x4" plate, 2mm holes on 4mm centers, in a grid pattern. The kicker:
no burr AND no countersink permitted on the hole, top or bottom. The
grid is being used in a MRI machine, and they fill the holes with an
MRI-opaque gel, which projects a grid of dots onto the MRI image.
They fill the holes by spreading on the gel and then scraping it off.
Since its a shadow that's being projected, the size of the dot is the
widest part of the hole, thus no countersink in order to maintain the
hole size. I drilled the holes on my Taig CNC, with a 135 degree
split point drill bit (brand new, screw machine length) at 5 IPM, 7500
RPM, no peck. Still had a few minor burrs. The part got wet-sanded
on the surface plate with 600 grit SiC paper. This worked extremely
well for the one-off, but not practical for production.

One idea: modify the drilling fixture to drill through another piece,
preferably of the same material. Similar to using an extremely close
tolerance drill bushing. This will hold the burr down and the machine
won't see a change between the two pieces.

"Denis G." wrote in message
...
Probably this answer is more in the category of "misc. ramblings", but
could you use cooling from a stream of gas (CO2 or liquid N2) to cool
the plastic. Maybe you could get it to behave more "crystaline".
Alternatively, maybe you could add the same sort of cooling with
passages in the drill guide fixture.
Not sure about the economics of all this and you might make other
problems with condensing water on the drill guide fixture, etc., but
the plastic might behave better when cold.

Also consider a mist unit, properly tuned, they're mighty cold for little
money.

You can run straight water or a mix.

Cold air blast idea:

Nice out-of-box thinking!

Agreed! Thanks to those who suggested it. I'll mention it to the customer.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R



** Posted from http://www.teranews.com **