I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

"Charles A. Sherwood" wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck


Mixed reviews on that subject. Personally, I'd fix it, but there are some
that go out of their way to remove it. It's nice to know that the collet
isn't going to spin on you when you tighten the draw bar, which is it's real
intended purpose, not to drive the cutting tool, although I have no doubt
that it also helps in that department. In all my years on the machines
I've never run a mill without one, nor have I ever busted one, although the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago. I guess you might say it's a personal judgment
call.

Harold

On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are some
that go out of their way to remove it. It's nice to know that the collet
isn't going to spin on you when you tighten the draw bar, which is it's real
intended purpose, not to drive the cutting tool, although I have no doubt
that it also helps in that department. In all my years on the machines
I've never run a mill without one, nor have I ever busted one, although the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago. I guess you might say it's a personal judgment
call.

I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

Harold sez:

"I guess you might say it's a personal judgment call."

Yeah, Harold and a good call it is. The original designers had good reason
to include the pin and it should be left in. IMO, those that rant about the
pin not being really necessary are just looking for an excuse to justify
their sloppy procedures.

Bob Swinney



"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are
some
that go out of their way to remove it. It's nice to know that the
collet
isn't going to spin on you when you tighten the draw bar, which is it's
real
intended purpose, not to drive the cutting tool, although I have no
doubt
that it also helps in that department. In all my years on the
machines
I've never run a mill without one, nor have I ever busted one, although
the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago.
I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Robert Swinney" wrote in message
...
Harold sez:

"I guess you might say it's a personal judgment call."

Yeah, Harold and a good call it is. The original designers had good
reason
to include the pin and it should be left in. IMO, those that rant about
the
pin not being really necessary are just looking for an excuse to justify
their sloppy procedures.

Bob Swinney

That's more or less that to which I was alluding, Bob, but there are those
that feel their decisions are just as valid as mine.

I'm anal enough that I tend to jump through all the hoops when I'm on the
machines. I wipe out the spindle and wipe off the collet, then hit both
with a blast of air before assembling. I also am heads up enough to avoid
engaging the drawbar before the collet is properly seated in the spindle.
I'm the kind of guy that always wipes down the ways and oils the machine
before beginning work, and then I stop during the day and repeat. The oil
on my ways is ALWAYS fresh, never dirty. I tend to preach that concept,
but not many appreciate being told, so I don't do it any longer.
Hopefully those that didn't do it have learned to do so now. It's very
important to the longevity of ways and screws.

The one benefit of not having the indexing pin, and I don't take advantage
of it, is that if you use something like a Sjogren collet head (I do) and do
considerable heavy work, you tend to get a definite wear pattern from the
collet. If the collet had the ability to fit randomly, that would not
occur. To me, that is not enough of a reason to remove the indexing pin.

Harold

On Wed, 30 Jun 2004 20:35:46 -0500, "Robert Swinney"
wrote:

===Harold sez:
===
==="I guess you might say it's a personal judgment call."
===
===Yeah, Harold and a good call it is. The original designers had good reason
===to include the pin and it should be left in. IMO, those that rant about the
===pin not being really necessary are just looking for an excuse to justify
===their sloppy procedures.
===
===Bob Swinney
snip

I think that is a pretty unfair statement. A persons desire to have or
not have the index pin is certainly not a reflection of the quality
of their work proceedures by any means. Its akin to saying those that
use a China made tool to make an item will produce an item that is
inferior to an item made with an American made machine. Simply not
true as to an index pin in or out reflects on work proceedures or
quality of work produced.
Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wifes,
I had no input whatsoever.
Remove "nospam" from email addy.

"Roy" wrote in message
...
On Wed, 30 Jun 2004 20:35:46 -0500, "Robert Swinney"
wrote:

===Harold sez:
===
==="I guess you might say it's a personal judgment call."
===
===Yeah, Harold and a good call it is. The original designers had good
reason
===to include the pin and it should be left in. IMO, those that rant
about the
===pin not being really necessary are just looking for an excuse to
justify
===their sloppy procedures.
===
===Bob Swinney
snip

I think that is a pretty unfair statement. A persons desire to have or
not have the index pin is certainly not a reflection of the quality
of their work proceedures by any means. Its akin to saying those that
use a China made tool to make an item will produce an item that is
inferior to an item made with an American made machine. Simply not
true as to an index pin in or out reflects on work proceedures or
quality of work produced.
snip----

When you've spent as much time working in commercial shops as I have, you'll
come to understand exactly what he mean. To the man, those that cut
corners, be it in processes or how they approach machine tools, tend to be
not great machinists. The problem is that when they're surrounded by people
like themselves, there's no one to make them look as bad as they are.
Those with the greatest skills and ability deal with the field of machining
in a totally different way. If you've ever worked with someone that has
that level of skill, you'd know and understand it quite well. They stand
out. I've yet to see it any different, and I've been on machines since the
late 50's commercially. The very idea that a feature of a machine is
eliminated because a worker is incompetent (what else would you call it?)
and screws up a machine because they're either in too much of a hurry to do
it right, or don't know enough to do so, is a perfect example of sloppy
procedure, regardless of the reason. Sorry, I agree with Bob. It does
reflect on the work that is produced.

Harold

"Robert Swinney" wrote in message ...
Harold sez:

"I guess you might say it's a personal judgment call."

Yeah, Harold and a good call it is. The original designers had good reason
to include the pin and it should be left in.

Do you know their reasons?

IMO, those that rant about the
pin not being really necessary are just looking for an excuse to justify
their sloppy procedures.

Bob Swinney

I would say that those who get rid of the pin have actually used their
brain to figure out it's purposes and the disadvantages of having it.

Mark K.




"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are
some
that go out of their way to remove it. It's nice to know that the
collet
isn't going to spin on you when you tighten the draw bar, which is it's
real
intended purpose, not to drive the cutting tool, although I have no
doubt
that it also helps in that department. In all my years on the
machines
I've never run a mill without one, nor have I ever busted one, although
the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago.
I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Robert Swinney" wrote in message ...
Harold sez:

"I guess you might say it's a personal judgment call."

Yeah, Harold and a good call it is. The original designers had good reason
to include the pin and it should be left in.

Do you know their reasons?

IMO, those that rant about the
pin not being really necessary are just looking for an excuse to justify
their sloppy procedures.

Bob Swinney

I would say that those who get rid of the pin have actually used their
brain to figure out it's purposes and the disadvantages of having it.

Mark K.




"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are
some
that go out of their way to remove it. It's nice to know that the
collet
isn't going to spin on you when you tighten the draw bar, which is it's
real
intended purpose, not to drive the cutting tool, although I have no
doubt
that it also helps in that department. In all my years on the
machines
I've never run a mill without one, nor have I ever busted one, although
the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago.
I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Robert Swinney" wrote in message ...
Harold sez:

"I guess you might say it's a personal judgment call."

Yeah, Harold and a good call it is. The original designers had good reason
to include the pin and it should be left in.

Do you know their reasons?

IMO, those that rant about the
pin not being really necessary are just looking for an excuse to justify
their sloppy procedures.

Bob Swinney

I would say that those who get rid of the pin have actually used their
brain to figure out it's purposes and the disadvantages of having it.

Mark K.




"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are
some
that go out of their way to remove it. It's nice to know that the
collet
isn't going to spin on you when you tighten the draw bar, which is it's
real
intended purpose, not to drive the cutting tool, although I have no
doubt
that it also helps in that department. In all my years on the
machines
I've never run a mill without one, nor have I ever busted one, although
the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago.
I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 11:34:54 -0700, Harold & Susan Vordos wrote:



Mixed reviews on that subject. Personally, I'd fix it, but there are
some
that go out of their way to remove it. It's nice to know that the
collet
isn't going to spin on you when you tighten the draw bar, which is it's
real
intended purpose, not to drive the cutting tool, although I have no
doubt
that it also helps in that department. In all my years on the
machines
I've never run a mill without one, nor have I ever busted one, although
the
shank of one of my boring heads is a little buggered up from one from a
crash many years ago. I guess you might say it's a personal
judgment
call.

I noticed that a mill I was using in one "high end shop" had had the
indexing pin removed and asked the shop foreman about it. He told me that
it was really there for indexing of the collet to keep it from turning
when tighting or loosening the drawbar, but they'd pulled them from all of
the mills after someone engaged the drawbar and started tightening
it before the collet was indexed into the pin slot. The pin was soft
enough to shear off, but they had the devil of a time getting the collet
out without causing more damage.



Chuckle!

I'd question just how "high end" the shop was when they pull tricks like
that. My opinion? They should have replaced the guy that screwed up, not
removed the indexing pins from all the machines. But I digress. I
think it's a personal call, as I've stated, but anyone that worked for me
that made that call wouldn't be working for me at the end of the day. I,
by far, prefer to have those that have enough skill and talent to not screw
up instead of altering machines so they can't do so. To me, it's a sign of
a fine craftsman when he can operate equipment properly.

Harold

On Wed, 30 Jun 2004 22:15:18 -0700, Harold & Susan Vordos wrote:


Chuckle!

I'd question just how "high end" the shop was when they pull tricks like
that. My opinion? They should have replaced the guy that screwed up, not
removed the indexing pins from all the machines.

Have you ever used a machine with a power drawbar? On the ones most of
their mills were fitted with when you tripped the handle it took about 0.5
seconds to fully tighten the drawbar. I presume some one was changing the
collet and just tripped the handle a bit sooner than they meant to.

--
The instructions said to use Windows 98 or better, so I installed RedHat.

"Jim Levie" wrote in message
news
On Wed, 30 Jun 2004 22:15:18 -0700, Harold & Susan Vordos wrote:


Chuckle!

I'd question just how "high end" the shop was when they pull tricks like
that. My opinion? They should have replaced the guy that screwed up,
not
removed the indexing pins from all the machines.

Have you ever used a machine with a power drawbar? On the ones most of
their mills were fitted with when you tripped the handle it took about 0.5
seconds to fully tighten the drawbar. I presume some one was changing the
collet and just tripped the handle a bit sooner than they meant to.

No, I have not, but under that circumstance I can see how it could happen to
anyone. There was no mention of a power draw bar originally. If that be
the case, I stand corrected. Still, with just a *little* care, it could be
avoided!

I'm from the old school where everything that was done on a machine was done
by the operator. Skill level is what sorted out those that could from
those that could not. I can see that CNC has changed all that.

Harold

Lots of guys don't use 'em. My BP didn't have one when I got it, but
I replaced it.

Grant

Charles A. Sherwood wrote:

I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

Subject: drive pin on R8 collets
From: (Charles A. Sherwood)
Date: 30/06/04 18:51 GMT Daylight Time
Message-id:

I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??


The drive pin is a redundant item which does no good anyway. Many old mills
have them broken off and are none the worse for it - mine included. The drawbar
and taper is what holds the collet in position. If you're taking such huge cuts
that something slips against that much locking force then no poxy little pin is
going to help much.


--
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
Next time someone insults you remember it takes 12 muscles to smile politely
and try to pass it off but only 4 to reach out your arm and slap the ****.

On 30 Jun 2004 17:51:28 GMT, (Charles A.
Sherwood) wrote:

===I recently bought a used rockwell mill. There is no drive pin in the
===spindle that is suppose to engage with the R8 collet. My other mills
===do have drive pins. Is this a problem that I need to fix??
===I seem to remember this question before and it might be ok??
===
===thanks
===chuck
All the indexing pins, thats what it actually is and serves onbly that
purpose and thats to index the tooling........were removed from all
the machines in the USArmy machinist tech school, for no other reason
other than to eliminate a screwed up spindle or collet if a student
crashed the mill. An R-8 collet / spindle setup is self locking by
design, and the pin serves no part in driving it or keeping the collet
from rotating.

Its a mixed bag if you need to ndex your tooling replace it, other
than that its not needed.
Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wifes,
I had no input whatsoever.
Remove "nospam" from email addy.

In article ,
Roy wrote:
On 30 Jun 2004 17:51:28 GMT, (Charles A.
Sherwood) wrote:

===I recently bought a used rockwell mill. There is no drive pin in the
===spindle that is suppose to engage with the R8 collet. My other mills

[ ... ]

All the indexing pins, thats what it actually is and serves onbly that
purpose and thats to index the tooling........were removed from all
the machines in the USArmy machinist tech school, for no other reason
other than to eliminate a screwed up spindle or collet if a student
crashed the mill. An R-8 collet / spindle setup is self locking by
design, and the pin serves no part in driving it or keeping the collet
from rotating.

Well ... where it helps, really, is when loosening or tightening
the drawbar. It keeps the collet and drawbar from rotating as a unit,
without you having to stretch one hand up high to wrench the drawbar
while the other is down at the collet, holding it and the took in the
spindle firmly enough to keep it from rotating under the influence of
the drawbar.

But -- aside from that, it is not really necessary.

I've seen in the MSC flyers from time to time a tool which has
three flanges on a handle, to allow you to hold the collet from rotating
more easily (without a tool in it), or to allow you to unscrew the
collet from the spindle (without an index pin being there). The flanges
fit into the three radial slots on the collet's end, to allow you to
either rotate it or to stabilize it.

I think that this tool is intended to be used on CNC machines
where the collet is tightened by power assist.

Of course, none of my milling machines have such an index pin,
because one uses 30 taper, one uses 40 taper, and one uses ER
double-angle collets, none of which have such key slots.

The larger lahte (12x24" Clausing) does have such a pin in the
(5C) collet adaptor, which is helpful while I'm at the other end of the
headstock, screwing the drawbar down to the right point where the lever
will lock it. For *that*, I am glad to have the indexing pin.

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
...
In article ,
snip-.

Of course, none of my milling machines have such an index pin,
because one uses 30 taper, one uses 40 taper, and one uses ER
double-angle collets, none of which have such key slots.

It's been years since I last ran a mill with a 50 taper, but I recall that
even they have keys, only in this case they are drive keys. Large mills
are capable of turning large cutters, so they can easily overcome the taper
drive. The #50's with which I was familiar were used in spindles on
Cincinnati, Van Norman and K&T mills. The shoulder at the large end of the
taper had opposing slots that accepted hardened drive keys that were a part
of the spindle. Do your holders have such slots?

Harold

In article ,
Harold & Susan Vordos wrote:

"DoN. Nichols" wrote in message
...
In article ,
snip-.

Of course, none of my milling machines have such an index pin,
because one uses 30 taper, one uses 40 taper, and one uses ER
double-angle collets, none of which have such key slots.

It's been years since I last ran a mill with a 50 taper, but I recall that
even they have keys, only in this case they are drive keys.

Yes -- *drive* keys -- not index pins to keep the collet from
spinning while you tighten the drawbar. :-)

Large mills
are capable of turning large cutters, so they can easily overcome the taper
drive. The #50's with which I was familiar were used in spindles on
Cincinnati, Van Norman and K&T mills. The shoulder at the large end of the
taper had opposing slots that accepted hardened drive keys that were a part
of the spindle. Do your holders have such slots?

The Bridgeport BOSS-3 (Series I) has the 30-taper Erickson
spindle. The holders have the slotted flange, and this is used (in
place of a drawbar) to both index (with 180 degree out possible) and to
draw the taper up firmly. (A set of rotating ears fit through the slots
as well as the keys. When you rotate the locking collar, the rotating
ears swing over the flange and tighten against it to draw it in.

There are times (like with a boring/facing head) when I would
feel more comfortable with a drawbar. :-)

The Nichols mill (40-taper) is a bit different. What it has is
a pair of threaded holes for large Allen head cap screws to act as
drivers, and the official 1" arbors (and presumably other sizes) are
cross-drilled with about a 0.300" drill rod inserted through it, with a
set screw at right angles to keep the two ends equidistant from the
surface of the arbor. However, the Allen head cap screws will serve as
driving lugs for the slotted flanges as well -- and even for CAT-40 end
mill holders -- once you heat them to soften the Loctite, unscrew the
draw stud, and machine up a replacement neck with internal thread to
accept the standard drawbar. (I have done this with a couple of them
from eBay auctions in sizes which I could not find with the standard
flange.

Of course -- these *are* drive flanges, while the index pin for
an R8 has nowhere near the strength if you manage to overcome the
taper's friction drive. It will probably shear off in a hurry.

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
...
In article ,
Harold & Susan Vordos wrote:

"DoN. Nichols" wrote in message
...
In article ,
snip-.

Of course, none of my milling machines have such an index pin,
because one uses 30 taper, one uses 40 taper, and one uses ER
double-angle collets, none of which have such key slots.

It's been years since I last ran a mill with a 50 taper, but I recall
that
even they have keys, only in this case they are drive keys.

Yes -- *drive* keys -- not index pins to keep the collet from
spinning while you tighten the drawbar. :-)

Large mills
are capable of turning large cutters, so they can easily overcome the
taper
drive. The #50's with which I was familiar were used in spindles on
Cincinnati, Van Norman and K&T mills. The shoulder at the large end of
the
taper had opposing slots that accepted hardened drive keys that were a
part
of the spindle. Do your holders have such slots?

The Bridgeport BOSS-3 (Series I) has the 30-taper Erickson
spindle. The holders have the slotted flange, and this is used (in
place of a drawbar) to both index (with 180 degree out possible) and to
draw the taper up firmly. (A set of rotating ears fit through the slots
as well as the keys. When you rotate the locking collar, the rotating
ears swing over the flange and tighten against it to draw it in.

There are times (like with a boring/facing head) when I would
feel more comfortable with a drawbar. :-)

The Nichols mill (40-taper) is a bit different. What it has is
a pair of threaded holes for large Allen head cap screws to act as
drivers, and the official 1" arbors (and presumably other sizes) are
cross-drilled with about a 0.300" drill rod inserted through it, with a
set screw at right angles to keep the two ends equidistant from the
surface of the arbor. However, the Allen head cap screws will serve as
driving lugs for the slotted flanges as well -- and even for CAT-40 end
mill holders -- once you heat them to soften the Loctite, unscrew the
draw stud, and machine up a replacement neck with internal thread to
accept the standard drawbar. (I have done this with a couple of them
from eBay auctions in sizes which I could not find with the standard
flange.

Of course -- these *are* drive flanges, while the index pin for
an R8 has nowhere near the strength if you manage to overcome the
taper's friction drive. It will probably shear off in a hurry.

Thanks, DoN. It's been so many years that my memory is a bit foggy, but
you've described them exactly as I remember them. I am not familiar with
the smaller tapers aside from the quick change that I own. The real
popularity of the smaller tapers seems to have hit the market big time when
NC's and CNC's became popular, but by then I was well steeped in what I was
doing and didn't change. At that time there was no reason to do so. Today
I doubt I could get a job if that was my desire.

The quick change that I own is a Bridgeport product that has a Jacobs type
keyed head and end mill holders that have a small taper, much in keeping
with the large ones, although these are quite small. In looking at the
head, one could easily conclude that Jacobs made it for Bridgeport. From
your description of The Bridgeport BOSS-3 (Series I), I gather this system
is similar, if not identical.

The q/c head extends the length of the spindle considerably and you can feel
the difference on a Bridgeport, so I don't use it much. When doing a
production job that required a few different end mills, though, it was a
real time saver, so long as the demand was light duty.

I guess my entire point about the R8 is that the key is not intended to
drive the cutter, although there are times when it probably does. I'm of
the opinion it is there to prevent the collet from spinning when the thread
on the drawbar and the collet don't fit up well, be it from chips or other
reasons. Personally, I enjoy having the key in place and don't find it
difficult to install the collets properly. I guess it's all in what one
gets used to. I can see how easily a person could make the mistake of
installing a collet not lined up with the key when they were used to not
working with one. That in and of itself is pretty good reason to have the
key in place. Helps prevent learning what I consider to be bad habits when
running machines. The mileage of others is likely to vary.

Harold

d.

I've seen in the MSC flyers from time to time a tool which has
three flanges on a handle, to allow you to hold the collet from rotating
more easily (without a tool in it), or to allow you to unscrew the
collet from the spindle (without an index pin being there). The flanges
fit into the three radial slots on the collet's end, to allow you to
either rotate it or to stabilize it.

I think that this tool is intended to be used on CNC machines
where the collet is tightened by power assist.

Collet wrenches are used on collet closers to install/remove the collet. --Doozer

On 30 Jun 2004 17:51:28 GMT, (Charles A.
Sherwood) wrote:

I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck
Gretings Chuck,
A friend of mine who is probably the best machinist I know removes his
because the speed up tool changes. You don't need the key to hold the
collet still when tightening the drawbar if your collets and drawbar
have good threads. But, I keep mine because the drill chucks and
boring heads with R-8 shanks always go in the same. So you can put the
chuck in and it will always run true and the boring head will cut the
same size. My buddy agrees with this and he marks his tool shanks and
the spindle nose so they go in the same while at the same time
allowing faster tool changes otherwise. But he never forgets to line
up the marks. And I would aleays forget.
Eric R Snow,
E T Precision Machine

So after all these comments:

Keep it if you have it, don't worry if you don't?

Regards,

Robin

Robin sez: "So after all these comments:

Keep it if you have it, don't worry if you don't?"

Jeeze, Robin. I dunno! After considering all the comments here, I got to
feeling guilty and removed the pin in my mill. It wasn't all that hard to
get out; about 15 minutes with a rat tail file, upside down, did the trick.
Now my mill is as good as anybodys! Only thing I noticed is that now it
takes more pressure on the drawbar to make the tooling stay in place.

Bob Swinney



"Robin S." wrote in message
m...

Regards,

Robin

So after all these comments:
Keep it if you have it, don't worry if you don't?

Seem to me that everything will work just fine without it.
But you might find it annoying to change tooling because
you might need another hand to hold the collet from turning.
I will just have to try my "new" machine without the pin
for a while and see if it annoys me. If it does, add the pin,
but frankly it would have to annoy me a lot to pull the spindle
to replace the pin.

Thanks for all the wonderful comments!
chuck

I don't know about your mill, but on the bridgeport clones, The pin can
be replaced without disassembling the spindle. Its been a while but I
seem to recall an access screw was removed to get at the pin, the
spindle had to be indexed to get at the pin, and there was a lock screw
as well.

Charles A. Sherwood wrote:
So after all these comments:
Keep it if you have it, don't worry if you don't?


Seem to me that everything will work just fine without it.
But you might find it annoying to change tooling because
you might need another hand to hold the collet from turning.
I will just have to try my "new" machine without the pin
for a while and see if it annoys me. If it does, add the pin,
but frankly it would have to annoy me a lot to pull the spindle
to replace the pin.

Thanks for all the wonderful comments!
chuck

--
James P Crombie
Slemon Park, PEI
Canada
Machinist - 3D Cad Design - Amateur Astronomer

http://www.jamescrombie.com

I'e used alot of mills in alot of shops and my opinion is if its not
there it was never a problem. If its in there and ok leave it. If its
in there and sticking out too far take it out.

(Charles A. Sherwood) wrote in message ...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

I would say the advantages of leaving it out outweigh the
disadvantages of having one.
Having read some of the replies below, there seem to be two kind of
people:
Those that do everything by the book and those that take risks.

I bet you the ones that do everything by the book and claim to be
"good" engineers, will still make the mistake of trying to do up the
drawbar with the pin misaligned at least once, possibly causing
damage.
Also, I doubt that they are the "innovative" type. They are generally
great at doing things to plans, but crap at coming up with anything
new.
I would say that a "good" engineer is one that comes up with accurate
and innovative engineering regardless of the quality of the tools.
A "good" engineer also minimises the risk of ****-ups. I would
therefore leave the pin out for tooling that does not need it because:

1) You'd have to be a complete imbecille not to be able to tighten the
drawbar correctly without the pin in.
2) The collet is only likely to slip if you make a bad mistake, and
then it's safer if it does slip.
3) The advantages posted by others.

Mark K.

"markzoom" wrote in message
om...
(Charles A. Sherwood) wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

I would say the advantages of leaving it out outweigh the
disadvantages of having one.
Having read some of the replies below, there seem to be two kind of
people:
Those that do everything by the book and those that take risks.

I bet you the ones that do everything by the book and claim to be
"good" engineers, will still make the mistake of trying to do up the
drawbar with the pin misaligned at least once, possibly causing
damage.
Also, I doubt that they are the "innovative" type. They are generally
great at doing things to plans, but crap at coming up with anything
new.
I would say that a "good" engineer is one that comes up with accurate
and innovative engineering regardless of the quality of the tools.
A "good" engineer also minimises the risk of ****-ups. I would
therefore leave the pin out for tooling that does not need it because:

1) You'd have to be a complete imbecille not to be able to tighten the
drawbar correctly without the pin in.
2) The collet is only likely to slip if you make a bad mistake, and
then it's safer if it does slip.
3) The advantages posted by others.


Use it for a boat anchor and get a machine with a 40 or 50 taper
instead--yes, that would be one that has drive keys......

--

SVL

"PrecisionMachinisT" wrote in message
...

"markzoom" wrote in message
om...
(Charles A. Sherwood) wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

I would say the advantages of leaving it out outweigh the
disadvantages of having one.
Having read some of the replies below, there seem to be two kind of
people:
Those that do everything by the book and those that take risks.

I bet you the ones that do everything by the book and claim to be
"good" engineers, will still make the mistake of trying to do up the
drawbar with the pin misaligned at least once, possibly causing
damage.
Also, I doubt that they are the "innovative" type. They are generally
great at doing things to plans, but crap at coming up with anything
new.
I would say that a "good" engineer is one that comes up with accurate
and innovative engineering regardless of the quality of the tools.
A "good" engineer also minimises the risk of ****-ups. I would
therefore leave the pin out for tooling that does not need it because:

1) You'd have to be a complete imbecille not to be able to tighten the
drawbar correctly without the pin in.
2) The collet is only likely to slip if you make a bad mistake, and
then it's safer if it does slip.
3) The advantages posted by others.


Use it for a boat anchor and get a machine with a 40 or 50 taper
instead--yes, that would be one that has drive keys......

Chuckle!

That is the ultimate solution, isn't it?

Harold

"Harold & Susan Vordos" wrote in message
...

"PrecisionMachinisT" wrote in message
...


Use it for a boat anchor and get a machine with a 40 or 50 taper
instead--yes, that would be one that has drive keys......

Chuckle!

That is the ultimate solution, isn't it?

Harold



Yup, that Harold is no fool!!!

So now folks, I admittedly havent read but a handfull a replys on this
one.....

......BUT.....

If your running some ganged wheel cutters having some diameter to em inna R8
spindle in back gear onna Brigeport type mill at 78 rpms or such, you might
wanna make sure your drive pin is engaged.

Its called torque.

--


SVL

"PrecisionMachinisT" wrote in message ...
"markzoom" wrote in message
om...
(Charles A. Sherwood) wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

I would say the advantages of leaving it out outweigh the
disadvantages of having one.
Having read some of the replies below, there seem to be two kind of
people:
Those that do everything by the book and those that take risks.

I bet you the ones that do everything by the book and claim to be
"good" engineers, will still make the mistake of trying to do up the
drawbar with the pin misaligned at least once, possibly causing
damage.
Also, I doubt that they are the "innovative" type. They are generally
great at doing things to plans, but crap at coming up with anything
new.
I would say that a "good" engineer is one that comes up with accurate
and innovative engineering regardless of the quality of the tools.
A "good" engineer also minimises the risk of ****-ups. I would
therefore leave the pin out for tooling that does not need it because:

1) You'd have to be a complete imbecille not to be able to tighten the
drawbar correctly without the pin in.
2) The collet is only likely to slip if you make a bad mistake, and
then it's safer if it does slip.
3) The advantages posted by others.


Use it for a boat anchor and get a machine with a 40 or 50 taper
instead--yes, that would be one that has drive keys......


Do you mean like a piece of junk Bostomatic that doesn't use drive keys?
But relies on the 40 taper to hold the tooling?

Pete (g)

"Pete Logghe" wrote in message
m...
"PrecisionMachinisT" wrote in message
...
"markzoom" wrote in message
om...
(Charles A. Sherwood) wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck

I would say the advantages of leaving it out outweigh the
disadvantages of having one.
Having read some of the replies below, there seem to be two kind of
people:
Those that do everything by the book and those that take risks.

I bet you the ones that do everything by the book and claim to be
"good" engineers, will still make the mistake of trying to do up the
drawbar with the pin misaligned at least once, possibly causing
damage.
Also, I doubt that they are the "innovative" type. They are generally
great at doing things to plans, but crap at coming up with anything
new.
I would say that a "good" engineer is one that comes up with accurate
and innovative engineering regardless of the quality of the tools.
A "good" engineer also minimises the risk of ****-ups. I would
therefore leave the pin out for tooling that does not need it because:

1) You'd have to be a complete imbecille not to be able to tighten the
drawbar correctly without the pin in.
2) The collet is only likely to slip if you make a bad mistake, and
then it's safer if it does slip.
3) The advantages posted by others.


Use it for a boat anchor and get a machine with a 40 or 50 taper
instead--yes, that would be one that has drive keys......


Do you mean like a piece of junk Bostomatic that doesn't use drive keys?
But relies on the 40 taper to hold the tooling?



Naww, I would prolly hang onto that one.

--

SVL

"Charles A. Sherwood" wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck


Hi Chuck,
When I got my used Bridgeport clone, I couldn't afford the
tooling, so I made some R8 blanks up at the local tech colledge as part of a
cnc course I was taking. The instructor asked me how I was going to mill the
slot for the drive pin. I told him my machine didn't come with one. He told
me I'd better get it back in there, as he had seen an accident where the R8
arbour had slipped, and tightened the draw bar to the point where it had
broken, shooting it out of the top of the machine.

One of the blanks became a 6'' dia fly cutter, and I've always wondered if I
should have taken his advice, or if he was pulling my leg. Seems to me that
as the arbor slips it will tighen the draw bolt, and I imagine this will
stop the slip well before the UTS of the drawbolt has been reached. Also, if
that much torque was present, I couldn't see how the pin would hold it
either, so I didn't replace it. So far no problems in 15 years.

regards,

John

"john johnson" wrote in message . au...
"Charles A. Sherwood" wrote in message
...
I recently bought a used rockwell mill. There is no drive pin in the
spindle that is suppose to engage with the R8 collet. My other mills
do have drive pins. Is this a problem that I need to fix??
I seem to remember this question before and it might be ok??

thanks
chuck


Hi Chuck,
When I got my used Bridgeport clone, I couldn't afford the
tooling, so I made some R8 blanks up at the local tech colledge as part of a
cnc course I was taking. The instructor asked me how I was going to mill the
slot for the drive pin. I told him my machine didn't come with one. He told
me I'd better get it back in there, as he had seen an accident where the R8
arbour had slipped, and tightened the draw bar to the point where it had
broken, shooting it out of the top of the machine.

One of the blanks became a 6'' dia fly cutter, and I've always wondered if I
should have taken his advice, or if he was pulling my leg. Seems to me that
as the arbor slips it will tighen the draw bolt, and I imagine this will
stop the slip well before the UTS of the drawbolt has been reached. Also, if
that much torque was present, I couldn't see how the pin would hold it
either, so I didn't replace it. So far no problems in 15 years.

regards,

John

He was obviously bull****ting you, because if the drawbar was that
tight, it would have stopped the collet from slipping.
M.K.