Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old June 30th 04, 06:51 PM
Charles A. Sherwood
 
Posts: n/a
Default drive pin on R8 collets

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


  #2   Report Post  
Old June 30th 04, 07:34 PM
Harold & Susan Vordos
 
Posts: n/a
Default drive pin on R8 collets


"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


  #3   Report Post  
Old June 30th 04, 07:39 PM
Grant Erwin
 
Posts: n/a
Default drive pin on R8 collets

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


  #6   Report Post  
Old June 30th 04, 11:43 PM
Jim Levie
 
Posts: n/a
Default drive pin on R8 collets

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.

  #8   Report Post  
Old July 1st 04, 02:35 AM
Robert Swinney
 
Posts: n/a
Default drive pin on R8 collets

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.



  #9   Report Post  
Old July 1st 04, 03:21 AM
DoN. Nichols
 
Posts: n/a
Default drive pin on R8 collets

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 ---
  #10   Report Post  
Old July 1st 04, 06:10 AM
Harold & Susan Vordos
 
Posts: n/a
Default drive pin on R8 collets


"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




Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for reasonable quality 5C collets Paul T. Metalworking 18 January 26th 04 01:31 AM
low voltage PIR controlled lights for drive - where? keith UK diy 11 December 24th 03 08:49 PM
O.T. How come America and Canada drive on the "Wrong" side of the road Wayne Bengtsson Metalworking 9 September 16th 03 04:57 AM
O.T. How come America and Canada drive on the "Wrong" side of theroad Eastburn Metalworking 4 September 11th 03 08:53 PM


All times are GMT +1. The time now is 07:39 PM.

Powered by vBulletin® Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004-2020 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017