Our club workshop pillar drill really needs a new chuck.  We’ve got a
keyless jobby in mind but need to get the existing chuck off the spindle. 
The Progress 1S spindle has a neat slot, right through the spindle, and
just above the chuck.  Below that is a round knurled nut that can be
screwed down, presumably to help with chuck removal.  We just can’t
understand what the slot is for.  It’s about ¼” wide and ¾” high, and
there’s what looks like a block of steel full-width across the bottom. 
Can anybody clarify please?
I’m anticipating that the mount is probably going to be JT6.  It’s evident
that considerable BF&BI is going to be needed to free the taper.  I’d
guess that it’s been on there for 50+ years.  From the state of the round
nut it’s evident that others have been there before us!  The existing ½”
chuck simply says it’s a Jacobs 34.  Current-day Jacobs numbers have a
suffix which identifies the mounting taper e.g. 34-06 for JT6.  We’ve got
a pair of wedges but initial trials indicated that a force greater than we
could apply from a big toolmakers’ clamp would be needed.  Any thoughts?
Geoff Johnson

"Geoffrey Johnson"  wrote in message
news:A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet...
> Our club workshop pillar drill really needs a new chuck.  We've got
a
> keyless jobby in mind but need to get the existing chuck off the
spindle.
> The Progress 1S spindle has a neat slot, right through the spindle,
and
> just above the chuck.  Below that is a round knurled nut that can be
> screwed down, presumably to help with chuck removal.  We just can't
> understand what the slot is for.  It's about ¼" wide and ¾" high,
and
> there's what looks like a block of steel full-width across the
bottom.
> Can anybody clarify please?
> I'm anticipating that the mount is probably going to be JT6.  It's
evident
> that considerable BF&BI is going to be needed to free the taper.
I'd
> guess that it's been on there for 50+ years.  From the state of the
round
> nut it's evident that others have been there before us!  The
existing ½"
> chuck simply says it's a Jacobs 34.  Current-day Jacobs numbers have
a
> suffix which identifies the mounting taper e.g. 34-06 for JT6.
We've got
> a pair of wedges but initial trials indicated that a force greater
than we
> could apply from a big toolmakers' clamp would be needed.  Any
thoughts?
> Geoff Johnson
>
>

Sounds like a slot for an ejector drift  (wedge) to knock out Morse
Taper drills (or chucks)

AWEM

Andrew Mawson wrote:


> "Geoffrey Johnson"  wrote in message
> news:A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet...
> > Our club workshop pillar drill really needs a new chuck.  We've got
> a
> > keyless jobby in mind but need to get the existing chuck off the
> spindle.
> > The Progress 1S spindle has a neat slot, right through the spindle,
> and
> > just above the chuck.  Below that is a round knurled nut that can be
> > screwed down, presumably to help with chuck removal.  We just can't
> > understand what the slot is for.  It's about ¼" wide and ¾" high,
> and
> > there's what looks like a block of steel full-width across the
> bottom.
> > Can anybody clarify please?
> > I'm anticipating that the mount is probably going to be JT6.  It's
> evident
> > that considerable BF&BI is going to be needed to free the taper.
> I'd
> > guess that it's been on there for 50+ years.  From the state of the
> round
> > nut it's evident that others have been there before us!  The
> existing ½"
> > chuck simply says it's a Jacobs 34.  Current-day Jacobs numbers have
> a
> > suffix which identifies the mounting taper e.g. 34-06 for JT6.
> We've got
> > a pair of wedges but initial trials indicated that a force greater
> than we
> > could apply from a big toolmakers' clamp would be needed.  Any
> thoughts?
> > Geoff Johnson
> >
> >

> Sounds like a slot for an ejector drift  (wedge) to knock out Morse
> Taper drills (or chucks)

> AWEM

It might sound like it Andrew, but it ain't!
The slot's only an inch or so above the chuck.  This model definitely
doesn't have the modern, technological advancement of a MT drill hole.
G

Geoffrey Johnson wrote:
> Andrew Mawson wrote:
> 
> 
>> "Geoffrey Johnson"  wrote in message
>> news:A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet...
>>> Our club workshop pillar drill really needs a new chuck.  We've got
>> a
>>> keyless jobby in mind but need to get the existing chuck off the
>> spindle.
>>> The Progress 1S spindle has a neat slot, right through the spindle,
>> and
>>> just above the chuck.  Below that is a round knurled nut that can be
>>> screwed down, presumably to help with chuck removal.  We just can't
>>> understand what the slot is for.  It's about ¼" wide and ¾" high,
>> and
>>> there's what looks like a block of steel full-width across the
>> bottom.
>>> Can anybody clarify please?
>>> I'm anticipating that the mount is probably going to be JT6.  It's
>> evident
>>> that considerable BF&BI is going to be needed to free the taper.
>> I'd
>>> guess that it's been on there for 50+ years.  From the state of the
>> round
>>> nut it's evident that others have been there before us!  The
>> existing ½"
>>> chuck simply says it's a Jacobs 34.  Current-day Jacobs numbers have
>> a
>>> suffix which identifies the mounting taper e.g. 34-06 for JT6.
>> We've got
>>> a pair of wedges but initial trials indicated that a force greater
>> than we
>>> could apply from a big toolmakers' clamp would be needed.  Any
>> thoughts?
>>> Geoff Johnson
>>>
>>>
> 
>> Sounds like a slot for an ejector drift  (wedge) to knock out Morse
>> Taper drills (or chucks)
> 
>> AWEM
> 
> It might sound like it Andrew, but it ain't!
> The slot's only an inch or so above the chuck.  This model definitely
> doesn't have the modern, technological advancement of a MT drill hole.
> G
> 
I think we need a picture. All the progress drills I've seen have an 
ejector slot. The advent of a JT extension on the end of the spindle is 
(to me) a modern embuggerance seen on cheap chaiwanese drills.
Intruiging though!
Bob

On Sun, 17 Aug 2008 17:48:23 +0100, Bob Minchin
 wrote:

>Geoffrey Johnson wrote:
>> Andrew Mawson wrote:
>> 
>> 
>>> "Geoffrey Johnson"  wrote in message
>>> news:A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet...
>>>> Our club workshop pillar drill really needs a new chuck.  We've got
>>> a
>>>> keyless jobby in mind but need to get the existing chuck off the
>>> spindle.
>>>> The Progress 1S spindle has a neat slot, right through the spindle,
>>> and
>>>> just above the chuck.  Below that is a round knurled nut that can be
>>>> screwed down, presumably to help with chuck removal.  We just can't
>>>> understand what the slot is for.  It's about ¼" wide and ¾" high,
>>> and
>>>> there's what looks like a block of steel full-width across the
>>> bottom.
>>>> Can anybody clarify please?
>>>> I'm anticipating that the mount is probably going to be JT6.  It's
>>> evident
>>>> that considerable BF&BI is going to be needed to free the taper.
>>> I'd
>>>> guess that it's been on there for 50+ years.  From the state of the
>>> round
>>>> nut it's evident that others have been there before us!  The
>>> existing ½"
>>>> chuck simply says it's a Jacobs 34.  Current-day Jacobs numbers have
>>> a
>>>> suffix which identifies the mounting taper e.g. 34-06 for JT6.
>>> We've got
>>>> a pair of wedges but initial trials indicated that a force greater
>>> than we
>>>> could apply from a big toolmakers' clamp would be needed.  Any
>>> thoughts?
>>>> Geoff Johnson
>>>>
>>>>
>> 
>>> Sounds like a slot for an ejector drift  (wedge) to knock out Morse
>>> Taper drills (or chucks)
>> 
>>> AWEM
>> 
>> It might sound like it Andrew, but it ain't!
>> The slot's only an inch or so above the chuck.  This model definitely
>> doesn't have the modern, technological advancement of a MT drill hole.
>> G
>> 
>I think we need a picture. All the progress drills I've seen have an 
>ejector slot. The advent of a JT extension on the end of the spindle is 
>(to me) a modern embuggerance seen on cheap chaiwanese drills.
>Intruiging though!
>Bob

Funnily enough I've just been through the same exercise, more or less
- trying to make a better drill from a goer and a less worn non-goer.
The older one did indeed have a slot and it was/is for MT ejection.
The somewhat later one (1960's ish) doesn't have a slot and after
considerable head scratching the chuck was eventually removed and does
have a JT6 nose to the solid quill and a knurled collar with a
tommy-bar hole to remove the chuck. I'd guess the slot on the one in
question is for stopping the quill rotating while walloping the collar
tommy bar with a beating stick. 

 Where I went wrong was thinking that the collar would remove a MT
from the quil so I was screwing it the wrong way Doh! obvious once
it's all apart, but not so when you've got one that _is_ like that on
the bench and this one refuses to budge. 

The initial intention was simply to swap the quills since the old one
is presumably slightly bent as it orbits a little - useable, but
irritating. Not possible, although externally the two drills look near
identical, the quills are different dias. and different chuck fitings.
OK so swap the whole head, got to swap a 1ph for a 3ph motor, but not
the end of the world. 
NO.... Another twist is that the old one has a 2.750" pillar the later
one has some cock-eyed size approx 69.6mm (about 015" below the older
one) so swapping the whole head wasn't possible. Ah OK thunk I, swap
head and pillar, but then the table doesn't fit and the pillar is
loose in the base.

In the end and by a staggering coincidence I had a bit of 2.750 bar
recovered just a month ago from a horizontal mill I scrapped and near
enough the right length. So I turned the top 8 1/2" down by 015" so
the 'new' head fits at the top and the original table and base are all
OK below. What a palava for what looks like a hours tinkering before
lunch......

Richard

In article <A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet>,
Geoffrey Johnson  wrote:
>I’m anticipating that the mount is probably going to be JT6.  It’s evident
>that considerable BF&BI is going to be needed to free the taper.  I’d
>guess that it’s been on there for 50+ years.  From the state of the round
>nut it’s evident that others have been there before us!  The existing ½”
>chuck simply says it’s a Jacobs 34.  Current-day Jacobs numbers have a
>suffix which identifies the mounting taper e.g. 34-06 for JT6.  We’ve got
>a pair of wedges but initial trials indicated that a force greater than we
>could apply from a big toolmakers’ clamp would be needed.  Any thoughts?
>Geoff Johnson

To solve this problem on my old pillar drill which did not have a Morse
Taper and ejection slot, I dismantled the spindle from the quill, set
the spindle up in the lathe using a 3 jaw steady and drilled a hole
through the back of the chuck and tapped it for some suitable size (M6)
and used a suitable capscrew to push the chuck off.  I now predrill
keyed chucks before fitting them on arbors. This works well
for keyed chucks but not for the albrecht pattern keyless models.

Alan

The Jacobs 34 chuck comes in at least two forms of mount, the JT taper
mount and a threaded mount. The threaded mount is a female 5/8 X
16thread. The chuck body may also have a locking screw through the
centre of the body.

To find out if your chuck is of the threaded type look for the model
number, if it is 34B and stamped under the opening sizes is 5/8 16, it
is a threaded mount.

If either threaded or JT mount, the slot in the spindle may be for a
bar to be used to hold the spindle while the chuck is removed.

These mounts can be a real sod to undo, both screw and JT mounts. A JT
mount number 34 chuck which wouldn't come apart with kindness so I
pressed the chuck apart leaving the body on the mount,drilled a hole
through the centre, made a ram, put the chuck in a manual press, heated
the body with a blowtorch until it came apart - with a loud bang!!

Good luck!

John


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View this thread: http://www.rcgroups.com/forums/showthread.php?t=910199

Alan Bain wrote:

> In article <A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet>,
> Geoffrey Johnson  wrote:
> >I’m anticipating that the mount is probably going to be JT6.  It’s evident
> >that considerable BF&BI is going to be needed to free the taper.  I’d
> >guess that it’s been on there for 50+ years.  From the state of the round
> >nut it’s evident that others have been there before us!  The existing ½”
> >chuck simply says it’s a Jacobs 34.  Current-day Jacobs numbers have a
> >suffix which identifies the mounting taper e.g. 34-06 for JT6.  We’ve got
> >a pair of wedges but initial trials indicated that a force greater than we
> >could apply from a big toolmakers’ clamp would be needed.  Any thoughts?
> >Geoff Johnson

> To solve this problem on my old pillar drill which did not have a Morse
> Taper and ejection slot, I dismantled the spindle from the quill, set
> the spindle up in the lathe using a 3 jaw steady and drilled a hole
> through the back of the chuck and tapped it for some suitable size (M6)
> and used a suitable capscrew to push the chuck off.  I now predrill
> keyed chucks before fitting them on arbors. This works well
> for keyed chucks but not for the albrecht pattern keyless models.

> Alan

Thank you both Alan, John and the earlier responders.
The chuck, as I orignally said is simply marked `Jacobs 34'.  Nothing else
other than its Hartford Connecticut place of birth and the size 0-1/2". 
The cross-slot in the spindle is almost filled up with a recangular block
that will slide just a bit from side to side.  There is no longitudinal
hole above the slot and it's all way too close to the chuck to be MT
related.  Four knowledgable club members looked at it on Monday evening
but none could shed light on the assembly.
We decided it's almost certainly a Jacobs taper and definitely a wedges
job.  Just need to work out how to apply the appropriate force without
damaging the important bit.
I've taken pics but got nowhere to post them.  If you're interested in a
butcher's, mail me on geoff(at)johnsonlb(dot)plus(dot)com and I'll gladly
send them.
Geoff

Alan Bain wrote:

> In article <A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet>,
> Geoffrey Johnson  wrote:
> >I’m anticipating that the mount is probably going to be JT6.  It’s evident
> >that considerable BF&BI is going to be needed to free the taper.  I’d
> >guess that it’s been on there for 50+ years.  From the state of the round
> >nut it’s evident that others have been there before us!  The existing ½”
> >chuck simply says it’s a Jacobs 34.  Current-day Jacobs numbers have a
> >suffix which identifies the mounting taper e.g. 34-06 for JT6.  We’ve got
> >a pair of wedges but initial trials indicated that a force greater than we
> >could apply from a big toolmakers’ clamp would be needed.  Any thoughts?
> >Geoff Johnson

> To solve this problem on my old pillar drill which did not have a Morse
> Taper and ejection slot, I dismantled the spindle from the quill, set
> the spindle up in the lathe using a 3 jaw steady and drilled a hole
> through the back of the chuck and tapped it for some suitable size (M6)
> and used a suitable capscrew to push the chuck off.  I now predrill
> keyed chucks before fitting them on arbors. This works well
> for keyed chucks but not for the albrecht pattern keyless models.

> Alan

Thank you both Alan, John and the earlier responders.
The chuck, as I orignally said is simply marked `Jacobs 34'.  Nothing else
other than its Hartford Connecticut place of birth and the size 0-1/2". 
The cross-slot in the spindle is almost filled up with a recangular block
that will slide just a bit from side to side.  There is no longitudinal
hole above the slot and it's all way too close to the chuck to be MT
related.  Four knowledgable club members looked at it on Monday evening
but none could shed light on the assembly.
We decided it's almost certainly a Jacobs taper and definitely a wedges
job.  Just need to work out how to apply the appropriate force without
damaging the important bit.
I've taken pics but got nowhere to post them.  If you're interested in a
butcher's, mail me on geoff(at)johnsonlb(dot)plus(dot)com and I'll gladly
send them.
Geoff

In article <7_adnfgpMOq9eDbVnZ2dnUVZ8vudnZ2d@posted.plusnet>,
Geoffrey Johnson  wrote:
>Alan Bain wrote:
>
>> In article <A4CdnR0GjvUQtjXVRVnyjgA@posted.plusnet>,
>> Geoffrey Johnson  wrote:
>> >I’m anticipating that the mount is probably going to be JT6.  It’s evident
>> >that considerable BF&BI is going to be needed to free the taper.  I’d
>> >guess that it’s been on there for 50+ years.  From the state of the round
>> >nut it’s evident that others have been there before us!  The existing ½”
>> >chuck simply says it’s a Jacobs 34.  Current-day Jacobs numbers have a
>> >suffix which identifies the mounting taper e.g. 34-06 for JT6.  We’ve got
>> >a pair of wedges but initial trials indicated that a force greater than we
>> >could apply from a big toolmakers’ clamp would be needed.  Any thoughts?
>> >Geoff Johnson
>
>> To solve this problem on my old pillar drill which did not have a Morse
>> Taper and ejection slot, I dismantled the spindle from the quill, set
>> the spindle up in the lathe using a 3 jaw steady and drilled a hole
>> through the back of the chuck and tapped it for some suitable size (M6)
>> and used a suitable capscrew to push the chuck off.  I now predrill
>> keyed chucks before fitting them on arbors. This works well
>> for keyed chucks but not for the albrecht pattern keyless models.
>
>> Alan
>
>Thank you both Alan, John and the earlier responders.
>The chuck, as I orignally said is simply marked `Jacobs 34'.  Nothing else
>other than its Hartford Connecticut place of birth and the size 0-1/2". 

Having looked at a Jacobs 34 chuck in my workshop, I think
M10 looks like a more suitable size to tap the hole.  It was a Jacobs
32 which I tapped M6 for removal.

The main thing to watch if you go the drilling & tapping route is not
to damage the centre in the spindle in case you need to put the spindle
between centres e.g. to clean up the taper.  Clearly there should be a gap
between the back of the chuck and the end of the spindle, but care is
still needed.

Alan