# Repouring a Babbitt bearing headstock



## Privateer (Oct 14, 2013)

Ok, so I have an extra headstock that has had its babbitt removed, the fellow that owned it previously machined what appears to be bronze 2 piece bushings to sit in their place. It didn't work all that well from the looks of the scoring on them. So I'm toying with the idea of restoring the headstock with new babbitt bearings. Now I've seen quite a bit on youtube, and Keith Fenner has a couple of videos showing the process. That part doesn't appear to be terribly difficult or complex, though he does make things appear easy. The issue that presents the greatest challenge to me is how to secure the spindle or suitable core with the proper height and alignment to the ways. 

One approach I saw, the fellow used the tailstock and the thread gears to lock the spindle in its proper location. Very good idea, however the issues here are, this headstock a. doesn't have a spindle yet, and b. doesn't have the original babbit in place to make the initial set up. Right now I'm leaning towards a bar turned to match the spindle, held in place between centers of my original headstock and tailstock. I don't like the idea of doing a pour over the bed, but I don't really see a way around it. One of the methods keith used doesn't strike me as being accurate enough for alignment to the bed. Another idea I had was to pour the bearings in go, with shims in place spanning the bearing entirely, and completely fill the area with a solid mass, then somehow mount the headstock to the carriage, or perhaps place it in the bed, and use the carrage to push it towards the headstock and bore it.

Not really sure of the most efficient way of getting it done accurately, so I'm looking for additional input and ideas. Thank you in advance.

Terry


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## iron man (Oct 17, 2013)

Why not make timken bearings fit the housing instead of the babbit it should not be that hard at the very most maybe machine a sleeve or something to make them fit???


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## Privateer (Oct 17, 2013)

Not entirely sure that would be an option, as the geometry of the headstocks vary quite a bit between the babbitt and timkin versions, where the bearings are concerned. While I have read you can swap spindles with a bit of care, the only thing I've seen regarding a retrofit to timkin from babbitt includes replacing the headstock. Which I'm considering, but the challenge of redoing the babbitt is appealing too.

Terry


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## iron man (Oct 17, 2013)

You could use aluminum it makes a good bearing surface but if you want to make new babbitt bearings you could make a mold out of steel we use to blacken the surface of the mold with a torch so the babbitt would not stick to the mold and then pour the mold with a silver bearing material. This way you dont have to machine them once thay are in place. Ray


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## valleyboy101 (Oct 17, 2013)

If you have a woodworker friend who has back issues of Fine Woodworking, They had an excellent 3 or 4 page article on re pouring babbit bearings.  The article was in the early 80's - back when they were a serious magazine.  I can look up the issue if you like.
Michael


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## jamie76x (Oct 17, 2013)

At a shop I worked at  few years back I did some centrifugal Babbitt casting. The easy part was heating it and pouring I in.... The hard part was to get itto stick and no crack when cooling.  Pre-heating the base shell, using nasty chemicals to clean and flux and controlling the cooling .... No very fun.

If you are dead-set on Babbitt bearings maybe there are Babbitt inserts than you can put into custom bushing? Like rod or main bearing on a engine except perfectly round.


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## wwunder (Oct 18, 2013)

I don't know the first thing about it, but I saw this ad for a rebabbitting tool that might be interesting.

http://www.usedcowichan.com/classified-ad/Bearing-Rebabitter_19587774


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## SEK_22Hornet (Oct 18, 2013)

Check out www.rotometals.com for several different babbit alloys.  I have bought metal from them before and was not unhappy with the service or the price. I think I would consider turning a mandrel to the diameter of the bearing journal or slightly undersize. long enough to be positioned by the tailstock and steady rest. I think the longer the better, so that any alignment error would be lessened (assuming the mandrel is straight).  Once the mandrel is in position, go ahead and pour the babbit.  If the mandrel is made undersize, it would allow for some extra metal to scrape the bearing to make some small alignment corrections when the spindle is re-installed.  Just thinking out loud, so to speak....


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## Privateer (Oct 18, 2013)

SEK_22Hornet,

That was pretty much the idea I was having, taking a 3/4" bar to hold the spindle in alignment between the original headstock and tail. I've been looking at roto metals already, but I'm unsure as to which grade of babbitt would be the correct choice. I'm leaning towards the grade 7 'heavy pressure' choice, but I have zero experience in this area.

Terry


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## SEK_22Hornet (Oct 18, 2013)

There is some interesting and potentially helpful information on babbitt alloys and selection on wikipedia http://en.wikipedia.org/wiki/Babbitt_(metal).  A little note on McMaster's web site gives a tiny bit of insight, basically saying that lead based metal can work harden and crack under heavy loads and that tin based metals withstand higher rpm and heavy loads.  That all being said, I would think that the high tin content with nickel and Monel of ASTM Grade 2 or the super tough grade 3 might be a good choice. I suspect that there are only subtle differences between all of the high tin based alloys listed. I do find it interesting that the Grade 7 is listed as "heavy pressure" and it is lead based. I suspect it might not like jarring loads like intermittent cuts, such as rounding a square shaft would produce.


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## timmeh (Aug 29, 2014)

is there any chance of a picture or somewhat detailed description of what the headstock looks like sans babbitt?


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## Round in circles (Aug 29, 2014)

I suspect that the cast iron casings were machined on a vertical borer whiles the casing was being rough machined with the bearing caps in place.
 Then on removing the caps the casing was reheated  to allow it to normalize from the developed stresses , whilst it was it was starting to cool at the relevant temperature a thin wide bar of white metal was pressed into the seat and into the cap seat then as separate items , then the casing was left to cool or was controlled cooled to a handable temp  by oil quenching.

 This would leave the rough bearings well adhered to the cast iron . the ends of the bearings would then be milled off and the cap bolted to the shaft to be milled and reamered to the final required shaft sizes. Most white ( Babbitt's metal bearings do have some self lubrication quality .

 In my apprenticeship I had to use a drag & cope arrangement using a green sand  core to individually cast a bearing to the end of the main wheel rod of an old military use steam engine  this was an Engineering Apprentice exercise only , the engine was long gone . 

 The bearing was a mere 1/4" thick once it had been shaped down to side thrust dimensions,   bored &  scraped to an engineering fit using hand tools & a simple jig only . It's near 50 years ago but I seem to recall that you could cast to almost 1/2 " and inch providing you used hot ashes and hot sand banked about a foot thick around the filled mould to slow down the mould 's cooling rate  cool 

 My thoughts for your bearings are :-
Can you locate an engineering company who makes bespoke white metal lined steel  shell bearings out of a manufactured sheet  that you see on todays modern vehicles  They are available in a mind boggling range and some ( the bigger ones ? ) can even be rolled down to a specified thickness and shaped to a required diameter .. their fit would be better , you could " notch " the cap and the main seat just like it is done on a vehicle engine's crankshaft to stop the bearing rotating and use some of the one ounce glass oiler pots to visually see that you have oil a ready for your  bearings  .

 Another route you could think of using is that of a rail enthusiasts group who rebuild the old timers steam engines  in time honoured methods .. perhaps they will have an annealing oven in which you could heat the whole bare bones  cast iron casing ready to accept strips of rolled down to almost thickness white metal to be pressed in to the cup and seat . They should have some sort of vertical borer to allow you to correctly mill and ream the bearings in the correct alignment using the one of the  stock casting faces that have been precision ground at the production stage as the reference point for alignment . 


If you really want o play and aren't too worried as to whether it works first time you can also make an annealing oven yourself using several old cut open steel oil drums to make a four sided box and a lift off lid.

Build a big charcoal fire in it to get a bed of red & white hot ash about a foot deep and place the casting at least six inches above the heat once the ash bed is fully developed  , cover , and leave for twelve hours so the casting gets to dark ( barely )  red  then try laying in a pre made & cut to rough dimensions strip of bearing metal & clamping it in place using an 1/8" undersized turned shaft .    
 I'd have a play with some other scrap cast iron casing first ,  use a pyrometer to get the adhesion temps & white metal melting point exactly right so you don't melt everything .  

Hmmmmm ! Melt everything ????? .  
Perhaps with a pre heated casting done as above ,  have a bolt on through the middle shoe/half saucer set that seals to either side to the to the casing use high  silicone rubber sealer to seal it. have a silicone covering over the clamping bolts so they can be pulled free or if of a full thread bolt.. can be un screwed when every thing is cold to remove the bearing forms .  Fill the whole bearing cavity  solid including the space for side /end thrust surfaces .....do  same with bearing caps then when well cool and handable with bear hands remove the forms 7 start your milling and scraping marathon.

In 1974  I helped stoke an annealing oven out in Cyprus , for 18 hrs so we could preheat to weld a 1/2 ton  cast iron gear box casing that had thrown a bearing and shaft out the side . It worked well and is like as not still out there at work on the island .


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## timmeh (Aug 29, 2014)

some interesting info, cheers. the automotive style(or something along those lines) bearing conversion is the way i'm leaning at this stage, to keep surface finish quality rather than high RPM.
trying to stay away from repouring/foundry type stuff myself and i think if there was anyone around here who could repour for me, it would likely cost an arm and leg.
if the headstock is rough machined before the babbitt is applied, that's ideal. i wasn't sure whether a bearing like that would be poured onto unmachined bore(providing a better keying surface?) or not.
machined surface would mean i could knock out the babbitt metal and turn up some sleeve bearings
to suit.hew:
another thought that i have had was skimming and shrinking a sleeve onto the spindle, then boring the existing bearing to suit, but that would be dependant on how much material could be safely removed.
at the end of the day, i'm not in a position to go by trial and error, if i mess it up, i bin the lathe.


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## timmeh (Jul 7, 2015)

It's been a while, finally went with making up a new spindle from 4140. Found that the babbitt had no discernible wear, roughed out a spindle and had the final cuts done by cnc. Works a treat. A few alterations to improve on the original. Have managed to get it cutting 4140 @ 3"/3.5"dia, .050" doc, .005" feed, needless to say, "happy as a pig in poop".


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## wa5cab (Jul 7, 2015)

Tim,

Nice work.  But why didn't you thread the left end of the spindle?


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## Wes (Jul 8, 2015)

valleyboy101 said:


> If you have a woodworker friend who has back issues of Fine Woodworking, They had an excellent 3 or 4 page article on re pouring babbit bearings.  The article was in the early 80's - back when they were a serious magazine.  I can look up the issue if you like.
> Michael


As Michael said. The article appeared in Jan/Feb 1983 issue of Fine Woodworking. Written by Bob Johnson who "...restores vintage woodworking machinery..." as the footnote says. Good reading, highly recomended before you start your project. Can send you a PDF if you like.


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## timmeh (Jul 8, 2015)

It is. I left all that to the guy that did the final turning on a cnc machine. Same as original until you get to the left end, swapped outboard collar to the other side of the 32 tooth gear and put another bearing in its place as per inboard side of left journal. The bit at the end extends just through the change gear cover to keep crap out of the gears.


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## wa5cab (Jul 9, 2015)

OK.  But without it being threaded to the end, you can't attach a collet closer or spider.


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## turnitupper (Jul 9, 2015)

wa5cab said:


> OK.  But without it being threaded to the end, you can't attach a collet closer or spider.


Why not?.
John.


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## timmeh (Jul 9, 2015)

Collet closer, don't have or need one. Spider, i can put set screws through the spindle extension. And the original spindle would have had to have the nut removed to do either as the thread didn't reach past the nut, actually a full thread back inside it.


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## Strtspdlx (Jul 9, 2015)

Why not just push the headstock to the center of the bed or atleast far enough over to put a fixture on either end of the headstock to hold the spindle square to the bed in all directions? 


Regards-Carlo
Edit: I didn't see your other posts. I have figured something along the lines of a line boring fixture would've been your best bet in pouring and machining the new Babbit to correct tolerances and alignment.


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## wa5cab (Jul 9, 2015)

Yes, but the lathe may well outlive you.   

As to having enough threads, read any of the collet closer instructions.  The closer sleeve replaces the threaded collar.  You made the spindle longer, and I just couldn't see any reason to do that except to avoid the necessity to remove the collar.  But you are correct.  If you never intend to use any collets, short term it's a moot point.


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## timmeh (Jul 9, 2015)

I actually didn' have to repour/modify the babbit. As it turns out there was no real wear in the journals. Found a couple of pieces of scrap PG bar to place in the journals to check cap clearances. Set up a dial gauge over the bare(caps off) headstock to check difference between the two(.125"+/- .00025"), and checked the bottom of the journal along its length(+/- .00025"). May have had a little wear in the caps, due to the original spindle being undersize .002" at left end, .006" at right end. After running in ended up with just under .0015" clearance in right journal after all the oil has drained away. It's done some relatively heavy turning and some interupted cuts and doesn't appear to be getting any worse.
 Oh and apologies for hijacking the thread!


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## louosten (Jul 14, 2015)

Gentlemen;
This is a really interesting thread, as I also have an H36, 10" Atlas with Babbitt bearings (76 years old!). I pulled the bearing caps off, cleaned up the journal surfaces, and put in some Plasti-gage to see what my clearances were. If I did it correctly, the clearance was .0015 on both journals. Not being a bearing expert, I'd like some reassurance that this is OK, and that I need not concern myself with headstock replacement issues. Thanks in advance,
Lou O.


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## wa5cab (Jul 15, 2015)

Lou,

All of my actual experience with babbit bearings has been in vehicle engines with forced oil lubrication.  So I don't have any feel for what's OK in an Atlas.  Go to Downloads, machine manuals, Atlas, Atlas lathe manuals, and Repairs and Technical Bulletins.  Look for Atlas Babbit Spindle Bearings,pdf, and download it.  I extracted this from an early edition MOLO.  This says that the proper fit will have a slight drag when you try to turn the spindle under no load conditions (belts slack and change gears in Neutral or disconnected).  I assume that that is with oil in the oil cups.  And this is with one bearing cap loose and one torqued down.  If you don't get that feel with either journal tight, you need to remove a shim from one side, re-torque the journal, and re-check.  But read the screed first.


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## timmeh (Jul 24, 2015)

Remove spindle.


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## timmeh (Jul 24, 2015)

Journals aren't overly flash, some light scoring, dark and polished areas. Measuring overall parallelism of journals and height difference(.125"). Bit of correct size material to check fit in journal and clearance of caps, then cut shims to suit.               Make new spindle.
Bearing in mind, old spindle was really bad. Babbit wasn't worn at all. Pays to check.


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## timmeh (Aug 9, 2015)

.0015" should be OK, if your spindle is in good shape and you still have some shims under both caps.


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## louosten (Aug 10, 2015)

Tim;
Thanks for the reply. When I first took the bearing caps off to do the Plastigage thing, there were no shims on the front bearing, and only 3 shims on one side of the rear bearing. I measured with the Plastigage once, to get a feel for where the bearings were originally. The rear bearing had more clearance, so I took out 1 of the shims and measured it again, with the result on both journals very close to .0015. So, my only option now is to maybe face off the bottoms of the bearing caps, if I need to close the gap further. At this point, as long as the lathe alignment is true, I'll probably be alright for another 10 years anyway without any changes. Do you concur?
Lou O.


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## wa5cab (Aug 11, 2015)

Lou,

I would first remove one more shim from one side of the left bearing cap and repeat the plastigauge test.  You should get the same results. Then after removing all of the plastigauge, check the spin feel with first one pair then the other pair of bearing cap bolts loosened.  If it spins freely, as it should, I would use very fine wet-or-dry paper on a good surface plate to try to reduce the clearance slightly.  Never under any circumstances would I try to use a mill to reduce the clearance.  

The bearing care instructions in the MOLO were written long before Plasti-gauge was invented.  And my only actual experience is this area is with Land Rover petrol and diesel engine crank and rod bearings,   Which are a different set of circumstances since those engines ran with typically 30 to 50 PSI oil pressure.  So I have no idea what Plasti-gauge indicated clearance corresponds to "a slight drag".  You will have to determine that experimentally.  On the bright side, should you find that you have gone too far with the sanding, you can always add shims to increase the clearance again.


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## timmeh (Aug 22, 2015)

After running in, i now have just shy of .002" clearance with oil drained away(after sitting idle for a few days), around .0015" with oil flowing through journals. Going well so far. That slight clearance is needed to get the "wedge action" of the oil started. Too close may result in excessive heat causing spindle/journal contact.
Clearances checked as per MOLO instructions, dial indicator perpendicular to spindle, on register behind thread, bar through hollow of spindle(take care with morse taper) push down + set zero, lift + take reading. If you don't have dial, you could do the same with a screw jack and feeler gauges, push down, wind up screw jack to touch, lift and check with feelers.


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## The Liberal Arts Garage (Sep 19, 2015)

I have  an old friend who regularly pours  bearings, mostly Fords,but is willing to
do other stuff ; specials are terribly  ex pensive, due to the machining costs of
Making plugs and jigs, etc.  I would try  porous bronze tubingwith a generous
Allowance inside and out;  get a good fit outside, and set up a tough, repeatable
Boring bar holder, and nibble away until you have a fit (in both senses ) ......BLJHB.


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