Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

On Sat, 5 Jan 2008 18:18:15 -0800 (PST), Gerry
wrote:

Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

..01? Ten thousands?

Cringe....

Yah..you have a chatter problem.

Isnt there a bearing adjustment take up nut at the ass end of the
front bearing?

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Gunner Asch wrote:

On Sat, 5 Jan 2008 18:18:15 -0800 (PST), Gerry
wrote:

Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

.01? Ten thousands?

Cringe....

Yah..you have a chatter problem.

Isnt there a bearing adjustment take up nut at the ass end of the
front bearing?

With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.


Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

While I have not used Plastigauge on the bearings yet I am wondering
is removing material from the mating surfaces of the bearing halves
may be an option. Have no idea how to do this other than a piece of
glass and some wet or dry and a lot of elbow grease. I don't know for
sure but I suspect that new bearings from the Sheldon parts people
would cost half of what a replacement lathe would cost me. Would it be
possible to use poured babbitt here if channels were machined in the
old bronze bearings?

In article
,
Gerry wrote:

While I have not used Plastigauge on the bearings yet I am wondering
is removing material from the mating surfaces of the bearing halves
may be an option. Have no idea how to do this other than a piece of
glass and some wet or dry and a lot of elbow grease. I don't know for
sure but I suspect that new bearings from the Sheldon parts people
would cost half of what a replacement lathe would cost me. Would it be
possible to use poured babbitt here if channels were machined in the
old bronze bearings?

Perhaps new bearings not from the Sheldon parts people? First you should
at least find out what they really would cost from there. Plain
bearings are cheap from MSC or McMaster-Carr. Buy oversize/undersize and
machine to fit, if need be.

For a truly cringe-worthy attempt, you could try slipping some small
shim stock between the bearing caps and the old bearing - cut the old
bearing first (unless it's already in halves? Then just dress the ends
if there's contact) so that it can be squeezed tighter without having to
crush it - less likely to get badly binding ripples that way. Further
fine adjustment could then be done with shims on the bearing caps mating
surface as is standard for Babbitt.

--
Cats, coffee, chocolate...vices to live by

Gerry wrote:


With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

That wasn't exactly a serious suggestion. It was an oblique poke at
Gunners suggestion to tighten a take up nut on the plain bearings.


While I have not used Plastigauge on the bearings yet I am wondering
is removing material from the mating surfaces of the bearing halves
may be an option. Have no idea how to do this other than a piece of
glass and some wet or dry and a lot of elbow grease. I don't know for
sure but I suspect that new bearings from the Sheldon parts people
would cost half of what a replacement lathe would cost me. Would it be
possible to use poured babbitt here if channels were machined in the
old bronze bearings?

Might be something useful on that lathes.co.uk site.

On Sun, 06 Jan 2008 11:10:38 -0600, "Pete C."
wrote:

Gerry wrote:


With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

That wasn't exactly a serious suggestion. It was an oblique poke at
Gunners suggestion to tighten a take up nut on the plain bearings.


Tapered plain bearings with a take-up are not unusual, though probably
not as common as split and shimmed headstock bearings.

--
Ned Simmons

On Sun, 6 Jan 2008 08:08:37 -0800 (PST), Gerry
wrote:
snip
While I have not used Plastigauge on the bearings yet I am wondering
is removing material from the mating surfaces of the bearing halves
may be an option. Have no idea how to do this other than a piece of
glass and some wet or dry and a lot of elbow grease. I don't know for
sure but I suspect that new bearings from the Sheldon parts people
would cost half of what a replacement lathe would cost me. Would it be
possible to use poured babbitt here if channels were machined in the
old bronze bearings?
snip
Removing play by filing down [or removing shims] from the bearing
caps is an old-old dodge as is rebabbiting the bearing.

IF the bearing surfaces on the spindle are in good shape, I
suggest trying the easy/cheap fix first, using modern materials.

For the quickest/easiest possible fix, try applying 0.005 thick
(assuming 0.010 shake/slop] teflon tape to the bearings, taking
care that the oil holes are open. While not a permanent fix, it
is easy and cheap, and may be adequate for your needs, with
ocassional/light lathe usage. Even if you have to redo every
year or so, this can be an adequate "repair." Note that
materials such as UHMW-PE may also be suitable as a combination
bearing material and shim as well as PTFE [teflon], and may be
more resistant to "cold flow."
click on
http://www.coorstek.com/products/tape.asp
http://www.m-source.com/group.cfm?gi..._Sided_Tap es
http://www.garlandmfg.com/plastics/pstape.html



For a more permanent fix Teflon impregnated epoxy liquids have
been specifically developed for exactly this purpose. You will
need to support the spindle in the correct [central] position
while the epoxy sets, be sure to apply release agent to the
spindle, calk the ends of the bearings so the liquid will not
leak, and prepare the brass bearings so the epoxy will adhere. In
many ways this is a "cold babbitt" with higher performance. This
is a common machine rebuild technique for plain bearings.
Moglice is a common brand, but there are others. It comes as
liwuid and paste in several flavors.
http://www.moglice.com/
http://www.moglice.com/newsite/pages...uildframe.html

In both cases [tape and liquid] finding a supplier for small
quantities you require will be the hardest part. Now if you can
use a car load ....

Let the group know how you make out, and any small quantity
suppliers you locate.

On Sun, 06 Jan 2008 11:10:38 -0600, "Pete C."
wrote:

Gerry wrote:


With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

That wasn't exactly a serious suggestion. It was an oblique poke at
Gunners suggestion to tighten a take up nut on the plain bearings.

I see you have never been in the guts of a Swiss Screw machine.
They generally have a tapered plain bearing with a matching spindle
shank, that works like a collet. You tighten a ring nut at the back
end of the bearing, which draws it in deeper, tightening the bearing,
and then you draw in the spindle itself. Its quite a simple and
elegant system and will last for many many years without replacing the
plain bearings. In some cases of the machines I service..well over 50.
under continous operation most of that time.

Id be surprised if a company as good as Sheldon didnt make some
provision for tightening up plain bearings besides the old Southbend
method of pulling out some shims and retightening.


Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

On Sun, 06 Jan 2008 12:53:05 -0500, Ned Simmons
wrote:

On Sun, 06 Jan 2008 11:10:38 -0600, "Pete C."
wrote:

Gerry wrote:


With plain bearings???

I think he needs to line bore the thing and convert it to tapered roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

That wasn't exactly a serious suggestion. It was an oblique poke at
Gunners suggestion to tighten a take up nut on the plain bearings.


Tapered plain bearings with a take-up are not unusual, though probably
not as common as split and shimmed headstock bearings.


Thank you.

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

I have heard of a "full shim pack" but have not found such an creature
in my machine. Perhaps because I don't know where to look. Sheldon did
make machines with Timkin roller bearing heads and ball bearing as
well, I believe, but my machine is not one of these. My lathe was sold
to the Navy in 43 so it possibly intended to go down with the ship. It
survived the war and was surplussed and ended up in storage for some
school system. I bought it three owners later. The Sheldon parts
people wanted $400 for a compound feed nut several years ago. With
that as a gauge I figure the price for a set of bearings would be
outrageous. Besides, they have not answered two email inquires in the
last two months.

On Sun, 6 Jan 2008 12:04:02 -0800 (PST), Gerry
wrote:
snip
I have heard of a "full shim pack" but have not found such an creature
in my machine.
snip
Given the age of your machine it is not unusual that there are no
shims. In many solid bearing machines, the new machine had 0.010
or more shims in the split bearing when it was machined or
fitted. These could easly be removed as the bearing wore to
compensate for wear, thus all the shims could have been removed.
I don't know if Clausing used such a system.

Some solid bearings had a taper at one or both ends and an axial
nut could be tightened to adjust clearence. Again I don't know
if Clausing used this system.

As you can always cut and install shims if you have a split
bearing to restore the original fit, your though to use a flat
plate and emory cloth to remove 0.010 seems like a good one.
Actually you may want to take of a little more and provide a few
shims to allow for future wear/fitting.

If you do this there will be a tendency for one end/side to be
ground down faster than the other, so change your grip and check
with a good midrometer FREQUENTLY. You can also add additional
weight to the fat side/end such as a dial indicator magnetic
base.

Lubrication will be critical on the tighter bearing, and oil cups
can be a big help if you have room. Also I find that synthetic
oil such as Mobil One is significently "slicker" in that the
bearings runn cooler by hand check than the specified no
detergent oil.

for oil cups examples click on
http://www.wttool.com/product-exec/p...m_source=froog
http://www.gitsmfg.com/wick-feed-oil-cups.asp
http://oilrite.thomasnet.com/viewite...ators/oil-cups
most any good mill suply will have in stock.


Good luck and let us know how you make out.

Gerry wrote:
Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

Maybe lucky it has plain bearings, the set of zero-clearance
bearings on my Sheldon R15-6 will cost several thousand $.
Is there any way to adjust the bearings, like caps with shims
that can have a layer peeled off? That's how you do it on the
Atlas lathes. Some others have a split in the bearing that can
be adjusted with a bolt.

What type of bearing is it? If Babbit or similar material, it
may be necessary to repour the babbit. If a bronze bushing, you
may be able to order a replacement bushing through an auto parts
store or machine shop supply. The lathe may be able to machine
the bushing to size, with a little care.

Jon

On Jan 5, 8:18 pm, Gerry wrote:
Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

Just pulled the caps and used plastigauge. I find 0.007in the inboard
and 0.005 in the outboard. No shims between the bearing halves.
Bearings are bronze. What would normal clearance be?

Now, if the top bearing was removed from it's cap and a piece of shim,
say 0.005 was placed behind the bearing, then what was protruding from
the cap was carefully worked down with 400 wet or dry on a piece of
glass, would this be an exceptable repair? Is there a better way to
accomplish the same thing?

On Sun, 6 Jan 2008 15:22:52 -0800 (PST), Gerry
wrote:

On Jan 5, 8:18 pm, Gerry wrote:
Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

Just pulled the caps and used plastigauge. I find 0.007in the inboard
and 0.005 in the outboard. No shims between the bearing halves.
Bearings are bronze. What would normal clearance be?

Now, if the top bearing was removed from it's cap and a piece of shim,
say 0.005 was placed behind the bearing, then what was protruding from
the cap was carefully worked down with 400 wet or dry on a piece of
glass, would this be an exceptable repair? Is there a better way to
accomplish the same thing?
================
The first thing I would try as it is cheap, easy and makes no
permanent changes is to install PTFE or HDPE wear tape. [see
other message on sources] in the top and bottom bearing halves to
maintain spindle location in reference to the tailstock/bed.

Complete coverage is not required, but you should try for 90-95%
on both the top and bottom, so you may want 0.0025 tape. Be sure
the oil holes are open, and no laps. You may want to put a 0.002
shim in the inboard side to insure parallel, however be sure to
check to see that the spindle is not [worn] tapered. Assuming
this is not a porous/oillite brass bushing, be sure the surfaces
are de greased for proper tape adhesion, using acetone or lacquer
thinner.

Lubrication will be critical with a tighter bearing.

Good luck and let us know how you make out.

"Gerry" wrote in message
...
On Jan 5, 8:18 pm, Gerry wrote:
Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?

Just pulled the caps and used plastigauge. I find 0.007in the inboard
and 0.005 in the outboard. No shims between the bearing halves.
Bearings are bronze. What would normal clearance be?

Now, if the top bearing was removed from it's cap and a piece of shim,
say 0.005 was placed behind the bearing, then what was protruding from
the cap was carefully worked down with 400 wet or dry on a piece of
glass, would this be an exceptable repair? Is there a better way to
accomplish the same thing?
Shimming the bearing(s) or dressing the caps will work fine if carefully
done and the surfaces are okay. It is best to leave a few thousandths of the
bearing protruding from the split to ensure that the bearings are held
tightly. Be sure that there is not more than very light drag on the bearings
and that they are well oiled.

Don Young

"Gunner Asch" wrote in message
...
On Sun, 06 Jan 2008 11:10:38 -0600, "Pete C."
wrote:

Gerry wrote:


With plain bearings???

I think he needs to line bore the thing and convert it to tapered
roller
bearings so the take up nut option would exist.

That's not an option. Not enough meat on the casting nor do I want to
redesign the headstock. Then there's the money issur in this as well.

That wasn't exactly a serious suggestion. It was an oblique poke at
Gunners suggestion to tighten a take up nut on the plain bearings.

I see you have never been in the guts of a Swiss Screw machine.
They generally have a tapered plain bearing with a matching spindle
shank, that works like a collet. You tighten a ring nut at the back
end of the bearing, which draws it in deeper, tightening the bearing,
and then you draw in the spindle itself. Its quite a simple and
elegant system and will last for many many years without replacing the
plain bearings. In some cases of the machines I service..well over 50.
under continous operation most of that time.

Id be surprised if a company as good as Sheldon didnt make some
provision for tightening up plain bearings besides the old Southbend
method of pulling out some shims and retightening.


Gunner

The infamous Sears 109 AA bench lathe used a tapered plain bearing. Simple
and elegant is right.

-Carl

Gerry wrote:
On Jan 5, 8:18 pm, Gerry wrote:

Been chasing chatter that has been getting worse lately. With a
crowbar under my chuck and a 1" bar in my chuck, I can measure
0.010-0.015" of vertical movement when I pick up on the chuck. Seems
like a lot to me. Lathe is an old Sheldon 11X56 circa 1942. Plain
bearings. What should I expect to see here? And what is the
recommended fix for what I have now? No money to buy a new lathe or
new bearings from the Sheldon rapists. Ideas? Comments?


Just pulled the caps and used plastigauge. I find 0.007in the inboard
and 0.005 in the outboard. No shims between the bearing halves.
Bearings are bronze. What would normal clearance be?

Now, if the top bearing was removed from it's cap and a piece of shim,
say 0.005 was placed behind the bearing, then what was protruding from
the cap was carefully worked down with 400 wet or dry on a piece of
glass, would this be an exceptable repair? Is there a better way to
accomplish the same thing?

The wear in this bearing is probably not uniform. It will
either be in the "up" or "back" direction, or likely both. If
you shim it uniformly, it will probably bind. Are these just
like auto engine main bearings? You might measure the journal
OD and thickness, and go to an auto parts shop and see if they
can find a bearing the same or slightly larger and the same
thickness. If larger, you just shave a little off the ends of
the bearing insert.

Jon

On Jan 6, 6:22*pm, Gerry wrote:
...
Just pulled the caps and used plastigauge. I find 0.007in the inboard
and 0.005 in the outboard. No shims between the bearing halves.
Bearings are bronze. What would normal clearance be?

The manual for my South Bend says to remove or add shims to achieve
0.001" to 0.002" play in the spindle nose (not the chuck or test bar).

You could mount a dial indicator on a long boring bar and check for
asymmetric wear by recording the readings on both bearing shells at
the front and rear upper edges and the bottom.

I've fixed a worn brass bearing by simply piling on solder and
scraping it until the shaft fit.

Jim Wilkins