# Are These Babbitt Bearings Still Good?



## Rannunzi (Sep 16, 2021)

I've got a new to me Atlas Craftsman 12x36 from the 30s. I was partially taking apart the headstock to do some cleaning and also to inspect the babbitt bearings. Can anyone with more experience tell me if these bearings are still good to continue using or if I need to pour new ones? Thanks in advance for any help!


----------



## woodchucker (Sep 16, 2021)

its not the look so much as the wear.  Are they sloppy? A score or two or three won't hurt the bearing. They are soft so they don't destroy the shaft from scoring. They are destroyed from being run dry though.  Hard to tell from the picture. Do you have much play?

on a second and third look, they don't look too bad, lots of meat left on them, they are marked up.. again Play?  is there an oiling hole , or wicks?


----------



## Rannunzi (Sep 16, 2021)

woodchucker said:


> its not the look so much as the wear.  Are they sloppy? A score or two or three won't hurt the bearing. They are soft so they don't destroy the shaft from scoring. They are destroyed from being run dry though.  Hard to tell from the picture. Do you have much play?
> 
> on a second and third look, they don't look too bad, lots of meat left on them, they are marked up.. again Play?  is there an oiling hole , or wicks?


No play as far as I can tell. There is an oil cup with a wick and I keep it oiled. Although after reassembly the back bearing seemed too tight and the spindle wouldn't free wheel if it was tightened all the way down. Strange given that it was super tight to begin with. I think a previous owner might have removed shims from it before it'd actually worn down enough, so I might have to add some shims back there. Thanks for the help though!


----------



## woodchucker (Sep 16, 2021)

I hope you oiled it before you put them back on. dry they may not turn as freely as you'd expect.
So do the rod test.
 while reassembled, stick a rod through and see if either side of the spindle lifts.
ALSO try forward to back. 
if you are tight, you may wish to shim it.
See if you can find the spec for how much play is proper.


----------



## Rannunzi (Sep 16, 2021)

woodchucker said:


> I hope you oiled it before you put them back on. dry they may not turn as freely as you'd expect.
> So do the rod test.
> while reassembled, stick a rod through and see if either side of the spindle lifts.
> ALSO try forward to back.
> ...


Can you explain a little more what you mean by the rod test? Stick a rod through where? Thanks.


----------



## woodchucker (Sep 16, 2021)

you stick a rod through the spindle bore.. you use that to find your play.

you pull first on one end then on the other.
it's more of a test than just grabing the spindle itself.


----------



## Rannunzi (Sep 16, 2021)

woodchucker said:


> you stick a rod through the spindle bore.. you use that to find your play.
> 
> you pull first on one end then on the other.
> it's more of a test than just grabing the spindle itself.


Ah I see. Thanks I'll give that a try tomorrow.


----------



## woodchucker (Sep 16, 2021)

put an indicator on the end you are testing to see how much play you have.
find in one of the manuals for your lathed what is the min-max.


----------



## brino (Sep 16, 2021)

I have no experience with Babbitt.

But, to be clear, this test is with the lathe power off!

Put a rod into the chuck to act as a lever, put an indicator on the outer surface of the rod and lift or push/pull the rod.
All you want to do is assess the static slop, or play, in the system.

Some folks even use a 2 x 4 between the rod and the lathe ways to apply lift.
Don't over do it you do NOT want to break anything, but cutting forces can really add up.

-brino


----------



## woodchucker (Sep 16, 2021)

brino said:


> I have no experience with Babbitt.
> 
> But, to be clear, this test is with the lathe power off!
> 
> ...


You indicate the spindle not the rod.
Yes never over do it.


----------



## woodchucker (Sep 16, 2021)

I don't use a chuck for the test, the idea is to try both ends.  it is just a lever inside the spindle bore....
what I read when rebuilding my lathe was to just use a bar, not the chuck. It works on a plain bearing shimmed type of spindle.


----------



## projectnut (Sep 17, 2021)

Another way to check how much wear there is in the babbit is to use some Plastigauge.  Remove the top cap, clean the debris from the spindle and bearing cap, place a piece of Plastigauge on the spindle, and replace the cap.  The Plastigauge will flatten out a bit.  Use the gauge on the paper packaging to determine the clearance.

Plastigauge is available at almost any auto parts store.  It's commonly used to check bearing clearance when rebuilding engines.  Here's a link to some available on Amazon:


			Amazon.com
		


Normally there is a stack of shims between the cap and body on babbited bearings when they are new.  As the babbit wears shims are removed to maintain the proper clearance.  If there weren't any shims left between the cap and the body, and there is excessive clearance when using the Plastigauge, the babbit is near the end of it's life.


----------



## woodchucker (Sep 17, 2021)

projectnut said:


> Another way to check how much wear there is in the babbit is to use some Plastigauge.  Remove the top cap, clean the debris from the spindle and bearing cap, place a piece of Plastigauge on the spindle, and replace the cap.  The Plastigauge will flatten out a bit.  Use the gauge on the paper packaging to determine the clearance.
> 
> Plastigauge is available at almost any auto parts store.  It's commonly used to check bearing clearance when rebuilding engines.  Here's a link to some available on Amazon:
> 
> ...


wow, plastigauge has changed since I was young. I built a race car back when I was  young. back then plastigauge was small piece of plastic, that you stuck on the bearing journal and tightened down on, then you then measured the width of it on and compared to a chart.  I look at that and am not sure what that is anymore.  looks way more complicated.


----------



## projectnut (Sep 17, 2021)

woodchucker said:


> wow, plastigauge has changed since I was young. I built a race car back when I was  young. back then plastigauge was small piece of plastic, that you stuck on the bearing journal and tightened down on, then you then measured the width of it on and compared to a chart.  I look at that and am not sure what that is anymore.  looks way more complicated.


It's still the same stuff.  It now comes in a sleeve that's used for measuring the final width.  Now it comes in both Metric and Imperial sizes.  It is time sensitive.  It only lasts a few months in the package before it gets hard.  Once it's hard it cracks and turns to dust rather than spreading out.


----------



## wa5cab (Sep 18, 2021)

If you can't torque the two bolts in either bearing cap to 15 to 25 lb-ft, you need to add back some of the missing shims  The original shim packs which Clausing still had some of when I checked several years ago were two pieces per bearing cap and were originally if I recall correctly 5 pieces of 0.001" shim stock laminated together.  The older MOLO's have a section on how to handle them.  Basically, if noticeable clearance was found with the rod and dial indicator, you peeled off one layer from the front pack, and replaced the caps and torqued them down and checked again.  If still too loose, you removed one layer from the rear and checked again.  But if all four shim packs are missing or removed and it is still too loose, then you must either re-pour the babbit or replace the head stock.  If you have to replace the headstock, I would replace it with a Timken headstock.  But do run the tests first.


----------



## Karl_T (Sep 18, 2021)

I have a babbit lathe and removed shims to eliminate play. BUT the spindle is below the tailstock. I know this by turning a point on a piece of stock and then putting a dead center in the tailstock and then sliding them together.  I live with it, this lathe is 16"x120" and only used on monster parts.

Anyway, look at this also.


----------



## pdentrem (Sep 18, 2021)

Plasti-Gauge is made for this kind of inspection work. Used lots on engine bearings over the years. I only buy one package per engine as it does age.
Pierre

Hot Rod V6 for a 1986 Jeep Cherokee.


----------



## projectnut (Sep 18, 2021)

The rod test may have been valid at the time it was introduced.  However like most everything technology moves on.  To put things in perspective Plastigauge wasn't invented until 1948.  The OP's lathe could have been as much as 18 years old when the new technology came into being.

Personally I would think the Plastigauge would be a far more accurate method to determine where the wear is and the extent of the wear.  I' used it on my 1916 Seneca falls star lathe to determine how much shim stock was necessary.  As for shim stock sizes they were originally limited to .001" per layer.  These days you can but shim stock in .0005" increments.  I have several 1" wide and 6" wide rolls of Precision and Trinity brand shim stock.  They range in thickness from .0005" to .030".


----------



## woodchucker (Sep 18, 2021)

projectnut said:


> The rod test may have been valid at the time it was introduced.  However like most everything technology moves on.  To put things in perspective Plastigauge wasn't invented until 1948.  The OP's lathe could have been as much as 18 years old when the new technology came into being.
> 
> Personally I would think the Plastigauge would be a far more accurate method to determine where the wear is and the extent of the wear.  I' used it on my 1916 Seneca falls star lathe to determine how much shim stock was necessary.  As for shim stock sizes they were originally limited to .001" per layer.  These days you can but shim stock in .0005" increments.  I have several 1" wide and 6" wide rolls of Precision and Trinity brand shim stock.  They range in thickness from .0005" to .030".


actually the rebuild manual by swells documents for the SB 9 , testing that way. The reason, the head caps don't come off. Its a split cap on one side. So yes it's still valid. But for the atlas we are talking about, the plastigage is perfect.


----------



## Weldingrod1 (Sep 18, 2021)

With plastigauge you are looking for maybe 0.0005 to 0.001" clearance. 0.002" is on the big side.
Foil Hershey bar wrappers were 0.0005" thick, BTW. Handy for us mechanical types ;-) snack and shim in one neat package...

Sent from my SM-G892A using Tapatalk


----------



## Bi11Hudson (Sep 18, 2021)

It was general practice with flat bearings to cast them in place oversize enough that a few shims would be necessary on the bearing cap(s). As the bearing wears in normal use, a shim would be removed to snug up the bearing. Of particular importance in this case where the bearing has run dry, the shaft may have spots of bearing material built up on it. When the bearing cap is replaced, this would make the bearing _*seem*_* to be too tight*. The shaft bearing surface should be "pristine", at least as near so as practicable.

From the looks of the photos, the bearing is not too bad and is *probably* usable as is. Bearing contact is not 100% even when new. Hand scraping a new bearing to about 85% should cover it. If you wanted to be sure, the shaft could be blued, the bearing cap installed, and the shaft spun over once ir twice. If there is less than 50% of the blueing left, you're good to go. Check that the oil holes and any oil grooves are clear and clean. See that the shaft is well lubricated on reassembly. *But not flooded*. If necessary to build up the bearing some, kitchen aluminum foil makes good shims. Several thin shims are a better chioce than a single thicker shim.

You must keep in mind that my experience as a helper was 50 years ago. And the machines that I (we) were working on were a _*little*_ larger than a lathe. As an electrician in the Coast Guard during the late 60s and early 70s, I worked with the ship yard mechanics on small ships commissioned in the late 40s to early 50s, rebuilding main motor pedestals and propeller shaft  bearings. The experience was a long time ago and my memory should be taken with a grain nay box of salt. But as a general overview, I still have some memories left.

.


----------



## projectnut (Sep 18, 2021)

My first experience with Babbeting was somewhat similar to yours.  The company I worked for had 2 huge ammonia compressors used for refrigeration.  The bearings on the 12' flywheels were babbited.  They were originally installed in the early 1900's and ran nearly 24/7 for nearly 80 years.  

About every 6-8 years an auxiliary compressor was brought in so the compressors could be serviced, and the bearings rebabbited.  The flywheels were lifted a couple feet and blocked while the mechanics melted out the old babbit and poured in new.  It was quite a job to watch.

Unfortunately there was a powerhouse fire in the late 1980's that destroyed them.  They weren't in all that bad a shape, but the cost to have new parts made was prohibitive.  They were replaced with  noisy (by comparison) screw compressors.


----------



## Rannunzi (Sep 18, 2021)

Thanks all for all the info! I've made myself some new shims and found the ideal number per bearing so that the play is minimized without binding the shaft. Using the rod test, I've measured 0.001" of play on the right bearing, which I think is acceptable (correct me if I'm wrong). My main concern was going to be that even with all shims removed, there'd be too much play, resulting in the bearings being unusable. If the bearings do get to that point while the lathe is still in my possession, should I make an attempt to re-pour them, or is that the time to just buy a new lathe?


----------



## woodchucker (Sep 18, 2021)

only you can answer that. if you find the lathe to be in great shape ... and it's what you want, better the devil you know, than the one you don't.
if you outgrow the lathe you may still want it as a second lathe.  Having a lathe is great to fix another lathe.

BTW glad things worked out.


----------



## wa5cab (Sep 19, 2021)

If the bearings get to the point of having all of the shims removed and has more than 0.001" of clearance, that is probably the time to eiither repour the bearings if you are up to it or to replace the headstock.  But I wouldn't scrap or part out the lathe unless the bed and lead screw wear is also excessive.  And an alternative to re-pouring the spindle bearings is the replace the babbit headstock with a Timken version.  The two internal parts of the babbit headstock that don't fit the Timken headstock are the spindle itself and the thrust bearing is not needed.  The other parts, if still good, are usable.


----------

