Subject: 3 AT Collets

From: Joseph Baccellieri <[email-masked]>
Date: Mon, 23 Sep 1996 21:21:07 -0700

Hello to all,

I am the happy owner of a 9"X18" Logan Lathe I am extremely pleased with
the condition and quality of this machine.  I am especially happy that
Scott Logan is available for parts and support.  My question is how
expensive are 3 AT collets and are they available?  What is the largest
capacity they come in? Can the lathe be modified to accept the more
common 5C collets?

Thanks for the help.

	Joe.

---

From: [email-masked] (Scott Logan)
Date: 24 Sep 1996 12:36:29 GMT

Hi Joe,

You knew I had to butt in here didn't you?

3-AT Collets are available from Hardinge (VERY EXPENSIVE!!!) or from MSC
(EXPENSIVE).  MSC's price is $31.24 each. Compare that to the price for
5-C, which is $6 to $25, depending on brand/quality. Check out some used
dealers, you might be able to find some.  Try Meridian Machinery
([email-masked]) or Plaza ([email-masked]).

Maximum capacity of 3-AT or 3-C is 1/2" round, 7/16 hex and 11/32
square.

There are front mount collet attachments available for 5-C collets,
including one made by Royal, but they are pretty expensive.  Also, front
mount "chuck-type" collet mounts available from MSC and others.  Through
hole capacity will still be limited by the spindle bore, in your case,
25/32".  

--
 ----------------------------------------
 Scott Logan [email-masked]
 09/24/96 07:35
 http://www.loganact.com

---

From: [email-masked]
Date: 24 Sep 1996 21:52:40 GMT

>hole capacity will still be limited by the spindle bore, in your case,

3C can be used in a 3AT machine - the only difference I can determine
is that the slot for the pin on the 3AT is longer than on the 3C.  I have
taken 3Cs and milled the slot to be longer with a carbide end mill.

This will only work if you can find a source of good, cheap 3C collets.
Unfortunately, this is unlikely.

===========================================================

 1959 BMW R50                                           Jim Rozen              
 1969 BMW R60US                                (JRR0 @ watson.ibm.com)                 
 1975 BMW R75/6    (The "new" one)        

===========================================================

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From: [email-masked] (PnP Nolan)
Date: 25 Sep 1996 02:51:42 -0400

In article <[email-masked]>, [email-masked] (Scott
Logan) writes:

> or from MSC
       ^^^^^^^^^^^
I keep hearing about MSC, can someone give me an 800 number or a fax
number to call for a catalog.

TIA

Peter

---

From: Steve Wellcome <[email-masked]>
Date: 25 Sep 1996 12:30:33 GMT

3AT collets go up to 1/2".  They're available; I think MSC
may carry them, or you can get them from Hardinge Bros.,
possibly for more money than you would believe any collet
could cost, but the quality is excellent.

There is NO WAY to modify your lathe to take 5C!  You'd
have to bore out your spindle to have a 1.25" hole down
the center of it, which would most likely not leave much
spindle left....
I have seen screw-on adapters that will take 5C collets,
but they necessarily have quite a bit of overhang and of
course you can't put long stock down through the spindle.

---

From: [email-masked] (Scott Logan)
Date: 25 Sep 1996 12:56:12 GMT

In article <[email-masked]>, From 
[email-masked], the following was written:
> 3C can be used in a 3AT machine

Incorrect.  A Collet, 5-C, 3-C, 3-AT or almost any other, makes contact
with the spindle or adapter in two places:  The front taper AND the back
bearing diameter. Otherwise the collet can be crooked.

According to the Hardinge catalog (a WONDERFUL reference tool), the 3-AT
has the following dimensions: Back Bearing Diameter .687, Thread
637-26, Length 2.313.  The 3-C has the following dimensions: Back
Bearing Diameter .650, Thread .640-26, Length 2.688.

And before anyone asks, the 5-C has the following dimensions: Back
Bearing Diameter 1.250, Thread 1.238-20, Length 3.281.  

 09/25/96 07:56
 http://www.loganact.com

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From: [email-masked] (Scott Logan)
Date: 25 Sep 1996 12:56:47 GMT

In article <[email-masked]>, From [email-masked] 

>From  the FAQ:

 -  MSC Industrial Supply Co.
      151 Sunnyside Blvd
      Plainview, NY  11803
      (800) 645-7270, (800) 255-5067 FAX, (516) 349-0265 FAX
      http://www.industry.net/msc

      Their 95/96 catalog is 3325 pages, and their selection has been
      described as "dumbfounding".  They claim same-day shipping and
seem       to meet this goal.  I realize non-US callers can't phone US
800       numbers, MSC suggests using the second FAX number above. 
Also,       their NY branch is at (516) 349-0330 if you're non-US and
need to       talk to somebody.

---

From: [email-masked]
Date: 25 Sep 1996 14:16:40 GMT

In <[email-masked]>, [email-masked] (Scott Logan) writes:
> Scott Logan 

Actually, it can.  And I've done it.  But I didn't say that it was the most
accurate setup.  But many home hobby machine folks do things like this,
just so they can come close to the convenience that a collett setup
gives.

Yes, I had to make a new drawbar, and yes, the rear diameter of the 
collet was a bit undersized, but it would center up the workpiece
within a thousandth, even given the fact that the the collets were 
used when I got them.  

But compare - in one case I have to buy 16 brand new 3AT collets - 
which fit the spindle of the old Pratt & Whitney speed lathe to
perfection.

In the other case, I get a good deal on a bunch of used, but serviceable
3Cs - and spend a few hours to modify them (lengthen the slots)
and another few to manufacture a drawbar (which I would have had
to do otherwise - the machine came without one).  Result - an improved
machine which has all the accuracy to do the jobs I need it to do, at
a fraction of the cost.

Given the choice (and the money), of course go and buy the correct
collet.  But often this hobby is about making do with what one *has*
on hand.  Like the article about *making* your own collets in this
months HSM.  You might say not to do it, because they would not
be heat-treated, and the accuracy would be impaired - but for home
hobby use, that's not an issue.  But money always is.

 1959 BMW R50                                           Jim Rozen

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From: [email-masked] (Russ Kepler)
Date: Wed, 25 Sep 1996 17:04:00 GMT

In article <[email-masked]>,
>could cost, but the quality is excellent.

I see that you've never bought a 2S collet, or any other non-stock
collet, from Hardinge...

>course you can't put long stock down through the spindle.

Actually, if the collet is drawn by a scroll the through-spindle hole
can be left completely clear.

-- 
Russ Kepler							[email-masked]

                    Please Don't Feed the Engineers

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From: [email-masked] (Chris Kantarjiev)
Date: 25 Sep 1996 17:46:35 GMT

Dave Sobel has provided me with a good selection of (round) 3C collets
(or variants, like 1A or South Bend 3) for my old SB 9x48, for
reasonable prices. I haven't gone looking for hex or other odd ones yet.

---

From: [email-masked] (James Kirkpatrick)
Date: 25 Sep 96 15:12:27 MDT

In article <[email-masked]>, [email-masked] (PnP Nolan) writes:
|>In article <[email-masked]>, [email-masked] (Scott
|>Logan) writes:
|>
|>> or from MSC
|>       ^^^^^^^^^^^
|>I keep hearing about MSC, can someone give me an 800 number or a fax
|>number to call for a catalog.

>From  the FAQ, for the second time in the last 3 days:

      http://mscdirect.com

      Their 96/97 catalog is 3555 pages, and their selection has been
      described as "dumbfounding".  They claim same-day shipping and seem
      to meet this goal.  I realize non-US callers can't phone US 800
      numbers, MSC suggests using the second FAX number above.  Also,
      their NY branch is at (516) 349-0330 if you're non-US and need to
      talk to somebody.  The catalog is free in the 50 USA states, and
      Puerto Rico and Canada.  A CD-ROM version might be available by
      mid-1997.

      Outside the US, their current (September 1996) policy is:

      *  The minimum order size for export orders is US$500
      *  Only products in stock at the time of shipment will be included on
         the order
      *  MSC will not process backorders or provide for special orders

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From: Mike Rehmus <[email-masked]>
Date: 26 Sep 1996 05:21:39 GMT

Ah, but there are the smaller (in length) Acorn collets that go up to
1 inch and more in size.  They are short enought that you can make an
adaptor.

ETR (Israel) makes a great set of collets.  Buy the collets, the clamping
nut and the wrench.  Then make your own adaptor out of, say, a 1.5" diameter
bar of leadloy (make it easy on yourself).

The steps are:
1. fit the bar to your spindle nose (just like a backing plate)
2. bore the front taper to fit the ETR collet series you have chosen
3. cut a thread to accept the clamping nut.

I made such an adaptor for my 6" craftsman about 3 years ago.  Total runout
of a bar clamped in the collet system equaled the runout of the spindle nose
itself.

Each collet costs between $20 & $35.  The nut cost about $25 and the wrench about
$25.

Best of all, the spindle bore is not reduced or blocked using this approach.

Best regards,

Mike Rehmus

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From: [email-masked] (Scott Logan)
Date: 26 Sep 1996 16:44:58 GMT

Dave,

I've contacted Hardinge to see about publishing that list, but have not
yet heard back. If they have a web page, that would be great, otherwise,
if they'll let me, I'll put it up on our page.

We'll see...

 09/26/96 11:44
 http://www.loganact.com

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From: [email-masked](Dave Ficken)
Date: 26 Sep 1996 12:13:42 GMT

In <[email-masked]> [email-masked] (Scott Logan)
>Bearing Diameter 1.250, Thread 1.238-20, Length 3.281.  
 A 3C collet can be used in most 3AT machines and vise versa. HOWEVER,
you need to change the spindle adapter and you may have to alter the
length of the rear bushing for the drawbar slightly.
 According to my copy of the Hardinge collet guide, the threads are
640-26 in both cases.
 I have some spare 3AT spindle adapters if anyone wants to convert from
3C to 3AT. Sorry can't help if you want to go the other way.
 Also, I agree that the Hardinge pamphlet is a valuable tool for
identifying collets. In fact, some time ago I ran off a bunch of copies
of the page that gives dimensions. I have been giving them away slowly
to anyone that sends a SASE and requests one. If anyone wants one,
send me a SASE @ Meridian Machinery P.O. Box 1 Babylon, NY 11702
Perhaps someone with a scanner can post a copy. Sorry, I am quite low
tech at this point.
 Regards,
Dave Ficken
Meridian Machinery "A different kind of Machinery Dealer"
http://hre.com/meridian

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From: [email-masked] (Mr Information)
Date: Fri, 27 Sep 1996 02:50:10 GMT

Is this Logan Lathe Week?  I just bought one two days ago, and my
questions are being answered before I even ask them.

Bob

>	Joe.

Bob

Americans aren't more violent than other people, just better shots.