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4" 4-jaw Union Mfg. chuck

paul.consolini
 

Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this 1-1/2-8 for mounting or an adapter plate for the 4 holes?
MERTON B BAKER
 

I'd go with the threads on the taper, especially if you can accurately
single-point 'em on your lathe, with the taper in the spindle. Be sure to
face the shoulder on the tapered arbor; that and a good threading job with
have the chuck running true. It might be a good Idea to drill & thread the
end of the taper for a drawbar, if it isn't already.

Mert

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of paul.consolini
Sent: Sunday, November 04, 2012 10:37 PM
To: 7x12minilathe@...
Subject: [7x12minilathe] 4" 4-jaw Union Mfg. chuck


Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller
threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this
1-1/2-8 for mounting or an adapter plate for the 4 holes?



------------------------------------

Yahoo! Groups Links
 

Paul, your lathe should be happy spinning a 4" chuck. Many 7x owners folk use them, though they usually get them from places like Little Machine Shop who sell versions which will bolt straight on. Indeed, some ambitious folk fit 5" chucks.

I suppose the counsel of perfection would be to make a backplate to match your spindle flange and fix it to the chuck using your four threaded holes, or even to machine the back of the chuck and fit studs so it will bolt direct to the flange. But Mert's suggestion will be perfectly adequate and easier to implement. As he implies, you will need a drawbar through the spindle to hold the arbor in place, and will not be able to pass thinner stock back through the spindle, but your 3" chuck can be used if you need to do that.

Be careful about stopping suddenly, and when cutting with the spindle running in reverse (unlikely, unless you have a rear toolpost). In either case, the chuck might tend to unscrew itself from the arbor.

Andy

--- In 7x12minilathe@..., "paul.consolini" <consolinipj@...> wrote:

Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this 1-1/2-8 for mounting or an adapter plate for the 4 holes?
 

Mert,

Apparently, it can not be done - the machinable end of taper is 1.5" in diameter, just for threading, no shoulder left.

Best regards,

Gennady

--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...> wrote:

Be sure to
face the shoulder on the tapered arbor;
J.Dunmyer
 

¿ªÔÆÌåÓý

Paul,
I¡¯d think that chuck would work fine on your 7X12. It should be mounted on an adaptor plate that¡¯s bolted to the chuck, so it mounts to the spindle with the existing 4 mounting holes.
?
Making an adaptor plate isn¡¯t real difficult, but you must follow the correct sequence if you¡¯re to get a good job. There are any number of articles on the Internet about fitting a backplate, the procedure is the pretty much the same whether it¡¯s on a threaded spindle nose or our lathes.
?
??????????????????????????????????????????????????????????????????????? <>
?

Sent: Sunday, November 04, 2012 10:36 PM
Subject: [7x12minilathe] 4" 4-jaw Union Mfg. chuck
?
?

Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this 1-1/2-8 for mounting or an adapter plate for the 4 holes?
lists
 

In article <k77c8p+n9oq@...>,
paul.consolini <consolinipj@...> wrote:
Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck. Would a
7x12 be able to spin this effectively? It has what looks to be a 1-1/2-8
threaded hole for mounting and 4 smaller threaded holes in a bolt circle
pattern, one every 90 degrees. LMS has a #3MT arbor with an unfinished
1.5" end - better to thread this 1-1/2-8 for mounting or an adapter
plate for the 4 holes?
I have an old Burndept 4" 3 jaw (Sizeable chunk of metal) and that is fine.

I'd go with an adaptor plate, that's what I did, as it leaves the spindle
hole clear.

--
Stuart
 

¿ªÔÆÌåÓý

I agree with Jim's advice on a backplate. The spindle pass through (lost with a nose mounted chuck) is very useful on the small bed length of the7x lathes

Gerry W
Leeds UK


To: 7x12minilathe@...
From: jdunmyer@...
Date: Mon, 5 Nov 2012 08:38:26 -0500
Subject: Re: [7x12minilathe] 4" 4-jaw Union Mfg. chuck

?

Paul,
I¡¯d think that chuck would work fine on your 7X12. It should be mounted on an adaptor plate that¡¯s bolted to the chuck, so it mounts to the spindle with the existing 4 mounting holes.
?
Making an adaptor plate isn¡¯t real difficult, but you must follow the correct sequence if you¡¯re to get a good job. There are any number of articles on the Internet about fitting a backplate, the procedure is the pretty much the same whether it¡¯s on a threaded spindle nose or our lathes.
?
??????????????????????????????????????????????????????????????????????? <>
?

Sent: Sunday, November 04, 2012 10:36 PM
Subject: [7x12minilathe] 4" 4-jaw Union Mfg. chuck
?
?
Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this 1-1/2-8 for mounting or an adapter plate for the 4 holes?
MERTON B BAKER
 

Well then! 1. Turn a ring & shrink Or hard solder it in place. Then you
have a shoulder. 2. Even better, take some 2" stock & turn a taper on it.
Put it in the spindle with a drawbar, turn the dia. for the thread, face the
shoulder, turn the large dia true.& thread it. The reason we have lathes
is to make stuff on 'em, right?

Mert

-----Original Message-----
From: 7x12minilathe@...
[mailto:7x12minilathe@...]On Behalf Of gennady_123
Sent: Monday, November 05, 2012 8:11 AM
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: 4" 4-jaw Union Mfg. chuck


Mert,

Apparently, it can not be done - the machinable end of taper is 1.5" in
diameter, just for threading, no shoulder left.

Best regards,

Gennady

--- In 7x12minilathe@..., "MERTON B BAKER" <mertbaker@...>
wrote:

Be sure to
face the shoulder on the tapered arbor;




------------------------------------

Yahoo! Groups Links
 

There's no problem with the lathe being able to handle a 4" chuck, it's a common upgrade. Some folks have fitted 5" chucks with no problems.

I'd go with an adapter plate; it lets you pass long stock thru & it avoids the risk of the chuck unscrewing itself from its mounting if you slow/stop the spindle too quickly.

Roy

--- In 7x12minilathe@..., "paul.consolini" <consolinipj@...> wrote:

Acquired an old (not sure how old) 4" 4-jaw Union MFG. chuck.
Would a 7x12 be able to spin this effectively?
It has what looks to be a 1-1/2-8 threaded hole for mounting and 4 smaller threaded holes in a bolt circle pattern, one every 90 degrees.
LMS has a #3MT arbor with an unfinished 1.5" end - better to thread this 1-1/2-8 for mounting or an adapter plate for the 4 holes?
paul.consolini
 

Looks like I'll probably go with the adapter plate. I took the chuck apart and what looked to be a blank back on the chuck was actually an adapter plate fitted to the recess in the back of the chuck.

The plate has 4 5/16-18 holes that the chuck was screwed to with socket heads and 4 1/4-20 holes slightly inboard and in line with the larger holes. Looks like all I need to do is drill and tap 4 holes on the 45 degree radials (the other holes are on the 90's, if you can visualize that, turn a registration recess and install studs and be good to go. The OD of the adapter is already a good snug fit to the chuck.

Any hints for a novice on accurately locating those holes?

--- In 7x12minilathe@..., "Roy" <roylowenthal@...> wrote:

There's no problem with the lathe being able to handle a 4" chuck, it's a common upgrade. Some folks have fitted 5" chucks with no problems.

I'd go with an adapter plate; it lets you pass long stock thru & it avoids the risk of the chuck unscrewing itself from its mounting if you slow/stop the spindle too quickly.
 

Sounds like a good plan.

The registration recess is the important bit; that's what sets the chuck concentric to the spindle. That said, if the chuck is an independent 4-jaw, the work will need to be set concentric to the spindle axis using a dial indicator. Thus, absolute concentricity of the recess isn't as essential as with a self-centering chuck, but eccentricity could cause imbalance and vibration.

According to this drawing:
< > the registration recess should be 55mm diameter, and the PCD of the bolts is 66mm PCD. You may find that the holes on your spindle flange are somewhat oversized, which may allow you a bit of leeway when setting out for the threaded holes in your backplate/adapter plate.

I suppose you might get really lucky and find that your existing 4 1/4-20 holes are at a PCD of 66mm, and that 1/4" (6.35mm) studs will go through the holes in your spindle flange.

Andy

--- In 7x12minilathe@..., "paul.consolini" <consolinipj@...> wrote:

Looks like I'll probably go with the adapter plate. I took the chuck apart and what looked to be a blank back on the chuck was actually an adapter plate fitted to the recess in the back of the chuck.

The plate has 4 5/16-18 holes that the chuck was screwed to with socket heads and 4 1/4-20 holes slightly inboard and in line with the larger holes. Looks like all I need to do is drill and tap 4 holes on the 45 degree radials (the other holes are on the 90's, if you can visualize that, turn a registration recess and install studs and be good to go. The OD of the adapter is already a good snug fit to the chuck.

Any hints for a novice on accurately locating those holes?

--- In 7x12minilathe@..., "Roy" <roylowenthal@> wrote:

There's no problem with the lathe being able to handle a 4" chuck, it's a common upgrade. Some folks have fitted 5" chucks with no problems.

I'd go with an adapter plate; it lets you pass long stock thru & it avoids the risk of the chuck unscrewing itself from its mounting if you slow/stop the spindle too quickly.
lists
 

In article <k7ckgm+firm@...>,
paul.consolini <consolinipj@...> wrote:
Any hints for a novice on accurately locating those holes?
Mount your chuck on your drill press, minus the adaptor plate (I assume
you have one) and use a drill to carefully line it up on the press as if
you were going to drill into one of the adapter plate fixing holes. The
tapping drill for the mounting hole size should be right and should go in
and out of the hole smoothly, without touching the sides as they say.
Clamp it very securely in position.

Lay the adaptor plate in position on top and carefully drill through with
the clearance drill size, being careful to minimise thread removal from
the mounting hole in the chuck - set your depth stop!

Rotate the adaptor plate 90 degrees till you can get a screw through it to
fix it to the chuck.

Now drill your second hole. Again rotate the plate through 90deg and you
can now have two screws holding the plate to the chuck. Repeat the
exercise till complete. The chuck itself must not be moved during the
process.

Hope this all makes sense.

--
Stuart
lists
 

On 07 Nov, Stuartlists@... wrote:
In article <k7ckgm+firm@...>,
paul.consolini <consolinipj@...> wrote:
Any hints for a novice on accurately locating those holes?
Mount your chuck on your drill press, minus the adaptor plate
<Snip>

Hope this all makes sense.
Sorry, I need to wake up fully, that was how to drill holes in an adaptor
plate to mount it onto the chuck but you already have those. A similar
principle of drill and rotate can be used in your case once you have
established the first hole on the correct PCD

--
Stuart
 

Here are the dimensions:



Roy

--- In 7x12minilathe@..., "paul.consolini" <consolinipj@...> wrote:

Looks like I'll probably go with the adapter plate. I took the chuck apart and what looked to be a blank back on the chuck was actually an adapter plate fitted to the recess in the back of the chuck.

The plate has 4 5/16-18 holes that the chuck was screwed to with socket heads and 4 1/4-20 holes slightly inboard and in line with the larger holes. Looks like all I need to do is drill and tap 4 holes on the 45 degree radials (the other holes are on the 90's, if you can visualize that, turn a registration recess and install studs and be good to go. The OD of the adapter is already a good snug fit to the chuck.

Any hints for a novice on accurately locating those holes?

--- In 7x12minilathe@..., "Roy" <roylowenthal@> wrote:

There's no problem with the lathe being able to handle a 4" chuck, it's a common upgrade. Some folks have fitted 5" chucks with no problems.

I'd go with an adapter plate; it lets you pass long stock thru & it avoids the risk of the chuck unscrewing itself from its mounting if you slow/stop the spindle too quickly.

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