# Babbit bearing headstock max spindle rpm



## Scubadave (Feb 14, 2019)

I. Have a master craftsman 101.07382 lathe. I am pretty sure the headstock has been changed because everything I find about that lathe says it has timken bearings but in fact has babbit bearings. I am installing a 3/4 hp. Variable a.c. motor and want to know the approx max spindle rpm so I can setup accordingly. Any ideas? Thanks in advance


----------



## Janderso (Feb 14, 2019)

Babbit?
You got a pic we can look at?
Someone much smarter will be along soon. Pics lubricate the conversation.


----------



## Scubadave (Feb 14, 2019)

I will send them when I get home about 12:30 cst


----------



## cathead (Feb 15, 2019)

For what it's worth, I have a Springfield Ideal lathe with babbitt bearings.  Max rpm on it is about 1400 rpm.


----------



## Scubadave (Feb 15, 2019)

Any ideas what the headstock is? As stated b4 101.07382 has timkin bearings.


----------



## Janderso (Feb 15, 2019)

Didn't Model T's have babbit main bearings?
What's the redline on a Model T? 
Nice lathe.


----------



## cathead (Feb 15, 2019)

Looks like babbit to me.  Model A Fords had babbitt bearings too and used shims for adjustment.  If you keep the babbitt
bearings well oiled on the lathe, it will last a long long time.  My older lathe has drip oilers and I turn them on when using
the lathe.  I have used it a lot and have never had to reshim the bearings in twenty years.  Your bearings look fine.   I wouldn't
worry too much about overspeeding the lathe, just keep it oiled well and put your hand on the bearing cap to verify that they
are just warm to the touch during a run.  That's a nice looking vintage Craftsman lathe, probably very early production unit.


----------



## projectnut (Feb 15, 2019)

I have  PDF versions of the 1936 and 1939 Sears Tool Catalogs.  Both have lathes similar to yours with Babbitt bearings in the headstocks.  It's hard to believe, but both machines are advertised as having a top speed of 2,100 rpm.  These are large catalogs with the 1936 version being nearly 9MB and the 1939 version being nearly 25MB.  They may take a few minutes to download if you have a slow internet service.


----------



## FOMOGO (Feb 15, 2019)

When you think about it, automotive shell bearings turn can turn upwards of 10k RPM. Pretty similar construction. As long as it has an oil film between the spindle and bearings life is good. Mike


----------



## Karl_T (Feb 15, 2019)

The auto bearings have a pressure oil pump system. that's the key to high RPM. Today's car engines use an insert that's really just a way to get away from casting babbit.

Condition of the bearing and oiling amount, will determine your max RPM. Another trick is to loosen the cap bolts when running fast. A guess here, but if you optimize all this, you could do 2000 for short runs.


----------



## Scubadave (Feb 15, 2019)

projectnut said:


> I have  PDF versions of the 1936 and 1939 Sears Tool Catalogs.  Both have lathes similar to yours with Babbitt bearings in the headstocks.  It's hard to believe, but both machines are advertised as having a top speed of 2,100 rpm.  These are large catalogs with the 1936 version being nearly 9MB and the 1939 version being nearly 25MB.  They may take a few minutes to download if you have a slow internet service.


Thanks for the downloads. Looks like mine is 1939 Master Craftsman 12 inch screw cutting lathe. Looked on internet for 2 weeks and VERY minimal info, 1 post here and bingo. Great forum.


----------



## David S (Feb 15, 2019)

Scubadave I highly recommend you post your Atlas questions in the Atlas / Craftsman section.  Robert over there is very knowledgeable on these machines, as are others of course, and welcome to the forum.

David


----------



## jbobb1 (Feb 15, 2019)

For what it's worth, I worked on many larger 3450 rpm electric motors that had babbit bearings. Bronze oil rings running on the shaft supplied oil.


----------



## chips&more (Feb 15, 2019)

Maybe not to worry about the highest speed it can go? But, what about that big and heavy chuck on it? How’s that babbitt bearing holding up next to the chuck?

And yes, the old Model T’s had rod and main babbitt bearings. And it was a “splash” oil system, no pump.


----------



## eugene13 (Feb 15, 2019)

So, when a sliding surface bearing is "up on oil" how thick is the oil in the thinnest part of the wedge?


----------



## Scubadave (Feb 15, 2019)

chips&more said:


> Maybe not to worry about the highest speed it can go? But, what about that big and heavy chuck on it? How’s that babbitt bearing holding up next to the chuck?
> 
> And yes, the old Model T’s had rod and main babbitt bearings. And it was a “splash” oil system, no pump.


My question about max rpm is only so I set the a.c. drive up right as to NOT over do it. I am looking to get zero to fastest off of back gear pulley and 1 spindle pulley. The motor is a 3/4 hp 3450 rpm. Bearings after lube and adjust has .002-.003 run out. Stuck rod in chuck and gave a little tug with dial indicater on chuck toward front. I am guessing that's ok. If bearings were needed why can't clausen find anything but timken bearings when I give them model #. I forget who at moment but someone here gave 1939 catalog that shows this exact lathe and it says babbit bearings right in ad.. I don't claim to know anything but I try .... Any advice is always appreciated.

Sent from my VS995 using Tapatalk


----------



## pontiac428 (Feb 26, 2019)

I have a 1937 10" with babbitt head.  I put together a Timken head at one point, and decided to stick with the babbitt because it ran tighter on the test bar.  I run it over the full range of sheaves without worry about overcooking anything.  When set up, the bearings have very little play and will last as long as you don't do anything horrible to it.  There is no replacement available, since babbitt has to be poured into the head with the spindle in one step and is now a lost art.


----------



## Bob Korves (Feb 26, 2019)

The speed would be related to the bearing diameter.  Start with that number and see what maximum speed machines with the same diameter bearings are running at.  Or, if nothing else, interpolate.  By saying size, I am really talking SFPM, which is probably what matters, that and what kind of oiling the bearings get and what kind of babbit it is.


----------



## agfrvf (Feb 26, 2019)

Scubadave said:


> My question about max rpm is only so I set the a.c. drive up right as to NOT over do it. I am looking to get zero to fastest off of back gear pulley and 1 spindle pulley. The motor is a 3/4 hp 3450 rpm. Bearings after lube and adjust has .002-.003 run out. Stuck rod in chuck and gave a little tug with dial indicater on chuck toward front. I am guessing that's ok. If bearings were needed why can't clausen find anything but timken bearings when I give them model #. I forget who at moment but someone here gave 1939 catalog that shows this exact lathe and it says babbit bearings right in ad.. I don't claim to know anything but I try .... Any advice is always appreciated.
> 
> Sent from my VS995 using Tapatalk


A.c. drive? Do you mean a Variable frequency drive? If so its better to get a lower speed higher power motor and wind it out. There are some nice used ones on fleebay atm.


----------



## Scubadave (Feb 27, 2019)

All ready own motor and vfd but still wondering about top rpm for those bearings. Previous post says dependant on bearing size , but doesn't give enuf info or formula to calculate. Unless it was assumed I know something I don't.

Sent from my VS995 using Tapatalk


----------



## agfrvf (Feb 27, 2019)

I would look at max rpm of the atlas 918(only had babbit) its on vintage machinery.


----------



## WCraig (Feb 27, 2019)

pontiac428 said:


> There is no replacement available, since babbitt has to be poured into the head with the spindle in one step and is now a lost art.


Um, "lost art" is a bit of an overstatement.  I believe you can order babbit from any of the big supply houses and there is lots of information out there on how to pour a bearing.  For example, Keith Rucker did a Youtube video recently on pouring a bearing for a sugar cane press.

Craig


----------



## agfrvf (Feb 27, 2019)

WCraig said:


> Um, "lost art" is a bit of an overstatement.  I believe you can order babbit from any of the big supply houses and there is lots of information out there on how to pour a bearing.  For example, Keith Rucker did a Youtube video recently on pouring a bearing for a sugar cane press.
> 
> Craig



Pouring babbit is not much different than casting lead. However to get it to be good enough for a machine spindle is a whole nother level. Compairing go karts to F1. No offense to Keith Rucker, I love his work.


----------



## projectnut (Feb 27, 2019)

WCraig said:


> Um, "lost art" is a bit of an overstatement.  I believe you can order babbit from any of the big supply houses and there is lots of information out there on how to pour a bearing.  For example, Keith Rucker did a Youtube video recently on pouring a bearing for a sugar cane press.
> 
> Craig


Maybe not a totally lost art, but something more like a blacksmith.  There are still people that can do both, just not nearly as many as a hundred years ago.  The company I worked for had it's own power house for generating high pressure steam and electricity.  They also had a huge refrigeration compressor room filled with early 20th century  ammonia compressors.  The compressors were originally steam powered, and later switched to 200 hp electric motors.  They had 12' diameter flywheels that ran on babbited bearings.  The flywheels were partially submerged in a pit so the bearings were easily accessible for rebabbiting.  The compressors ran 24/7 so every 3 to 4 years the flywheels had to be pulled and the bearings repoured.

The compressors were ancient by todays standards, but extremely cost effective to run.  They required little maintenance, and if parts did need to be made we had an onsite machine shop with highly skilled machinists.  Unfortunately in the late 1990's there was a fire in the compressor room that wiped out nearly all the compressors.  Since 80+% of the facility needed refrigeration there was no time to make all the parts necessary to get them back up and running.  It was a sad thing to see happen, but all the compressors were removed and either scrapped or sent to museums.  They were all replaced by more modern screw compressors.

Here's a link to a similar type of steam powered compressor.  This one is considerably smaller than the ones in the powerhouse where I worked.


----------



## Bob Korves (Feb 27, 2019)

pontiac428 said:


> There is no replacement available, since babbitt has to be poured into the head with the spindle in one step and is now a lost art.


Really?  Something makes me think I saw someone do that in a YouTube video, appeared to come out nice.  Unfortunately, cannot remember where I saw it...  Maybe David Richards?


Scubadave said:


> All ready own motor and vfd but still wondering about top rpm for those bearings. Previous post says dependant on bearing size , but doesn't give enuf info or formula to calculate. Unless it was assumed I know something I don't.
> 
> Sent from my VS995 using Tapatalk


If you compare a 2" spindle to a 4" spindle, identical in every other way, the speed of the sliding surfaces doubles, *at the same rpm.*  The bigger the spindle bearings get, the more difficult the surface speeds become to accommodate with leading to overheating, galling, and failure.  On the other hand, if only the diameter changes, and not the width of the bearings, load capacity is increased due to the larger total bearing area.  At some combination of diameter, load, and speed, Babbitt bearings will need improved Babbitt alloys and/or better oiling systems.  Automobile engines use Babbitt type materials at quite high rpm, but they have carefully designed oiling systems, with special oils, recirculated under pressure, good filtration, oil coolers, and highly accurate journals.  You will not find that on simple and inexpensive lathes from decades ago...


----------



## WCraig (Feb 27, 2019)

agfrvf said:


> Pouring babbit is not much different than casting lead. However to get it to be good enough for a machine spindle is a whole nother level. Compairing go karts to F1. No offense to Keith Rucker, I love his work.


Not sure why you say that.  I believe babbitt bearings are pretty forgiving.  When they are new, keep checking if they are heating up.  Otherwise, a bad bearing could get to the melting point of the babbitt.

For more information on babbitt bearings:





__





						Babbitt - What is Babbitt? - VintageMachinery.org Knowledge Base (Wiki)
					






					wiki.vintagemachinery.org
				






			http://www.alchemyextrusions.com/Babbitt/default.aspx
		






__





						Babbitt Information - American Power Service — Babbitt Bearing Repairs
					

Your Babbitt Bearing Specialists




					www.babbittrepair.com
				




etc.

BTW, using the Vintage Machinery page, I calculate that a tin-based babbitt bearing on a 2" shaft (for example) could run up to 4,500 rpm.  Did the OP mention the spindle size of the lathe?

Craig


----------



## Karl_T (Feb 27, 2019)

I have a 16" by 120" leBlond with shot babbit bearings...

Many years ago, I really looked into rebuilding this old machine. One part I never discovered was how to accurately hold the spindle in the exact right position while pouring in new babbit. Got to be accurate on a lathe.


----------



## pontiac428 (Mar 5, 2019)

Hey, OP, I just got to looking again at your pics and I think you should run what you've got.  You still have shims in your stack, the exposed portion of journal on the left side looks good, and the journal cap looks decent.  Adjust them and start making chips!


----------

