New Project Atlas Bearing Replacement

Just planning to move on to the next "clearout" project and need some advice if possible. I have had an old Atlas 10f under the bench for 10+
years and have decided that it is time to fix it or throw it. It is a "babbit" bearing model with the spindle bearings well past their sell by date. The bed is OK (quite good actually) and all the other bits are present and working. The machine turns reasonably parallel but faces off considerably convex. All of the shims have been removed and there is considerable side float in the spindle (possibly up to .010" or so). I already have three other lathes and don't want to throw this away although I don't want to spend much money on it either. Could I just change the "babbit" for some PB or will it wear very quickly with a soft spindle. Is there any other material that I could consider for the bearings, cast iron bar? Would Dural do a reasonable amount of service?
To be honest I would like to give this to a friend of mine who will use it to make a few bushes. I owe him a few beers so don't want to give him absolute rubbish. On the other hand he will use it only a few times a year if that. Any suggestions, thoughts or hard earned experience would be much appreciated. I have watched E-bay for many months for a roller bearing headstock but they fetch too much money for my intended thankyou "gesture". So anyone have a suitable "bodge", can't believe I said that!!
Best regards
Keith
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On 31 Mar 2006 16:06:21 -0800, jontom snipped-for-privacy@hotmail.com wrote:

Have a word with Mike Kurn (formerly of Acorn Tools, one of the UK manufacturers of Atlas clones), tel. 01784 434225. He keeps a wide range of spares for these lathes and can source others from the US. Always willing to offer advice as well.
Russell.
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jontom snipped-for-privacy@hotmail.com wrote:

Have you considered remetalling the bearings and remachining them? It can be done in a similar manner to the way a plumber would do a "wiped" lead joint.
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Hi There, There is a book offered by camden books that tells you how to do your own babbit bearings and if i remember correctly is quite simple. Either that or make your own bush and hand scrape it to size seems you have other lathes available. Hope this helps Colin Heath
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colinheath
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Babbitt metal is only about 25 to 30 brinell. You are right in thinking that Bronze or CuPb bushes will wear an unardened shaft. Duralumin is similar hardness and will also wear the shaft. Babbitting is simple as a set of basic steps, but that does not mean easy. It takes practice and good control of temperatures. For correct babbitting methods you can look at the info I put on www.hoyt-darchem.demon.co.uk. For a really cheap bodge, if the bearings are only worn a little, you could try depositing a layer of solder on top of the babbitt and then cutting it back to size. Solder is softer than babbitt, but is similar to the flash coating you get on some bronze and aluminium bearings. If you are only taking up a few thou of wear you might get away with it. It will not damage the shaft and if you have plenty of time but no cash it might give you some service life. From a professional standpoint it is a terrible bodge. Good luck. Phil
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Phil wrote:

Phil, thanks a great site and some really useful information. I have tried a little Babbiting before and as you say have found it very difficult. With a normal welding torch for a heat source I found it difficult to control temps and had some problem with getting the material to "stick" to cast iron. Pity I didn't do this research before I took early retirement as I would have had access to some very capable ovens then. I'm interested in your "terrible bodge" of course as I do indeed "have plenty of time but no cash". Any thoughts on suitable Babbitt preparation, flux and solder? The bearing has been "butchered" (previous to me - honest) to try and improve oil flow so maybe i could fill these in as well.
After some more investigation I see that the lower Babbitt is in fact breaking away from the headstock casting, looks to be a .004-.006 gap here but I suppose I could back it up with some suitable shim stock to provide support.
Phil if hardness is the issue how about some normal soft Aluminium, or will that "pick up" when running.
Anyway thanks for your ideas I certainly have more to ponder now. Thanks also to Russell and Colin for places to look for more information and of course to Briano who also suggests re-metalling. I think I might just give it a go.
Best regards
Keith
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wrote:

How much would a couple of pounds of whitemetal cost for Keith to machine into bearing shells from solid (or approximate castings) rather than trying to re-metal the existing bearings? I assume that this would hold no fears for him since it would be an easier job than doing the same thing with any bronze.
Mark Rand RTFM
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Mark Rand wrote:

Dave/Mark
An update (crisis) even before the job has started. Armed with great enthusiasm I was up early (for me) and as soon as the wife was out the door I was in the garage and away, or so I thought. My crisis is that when looking at the current settup the Babbitt was obviously poured into the casting and then bored, it does not appear to be machined half shells as I expected (don't forget I am aircraft based not machine tools). I then had a sudden thought that the headstock casting may not be that accurately machined and in using half shells of any material could in effect move the centre of the bearing even if the casting has been bored to provide a reasonable seating for the shells. End result is that I'm back here "thinking" rather than "doing" as I should be. I'm about to have a look to see if I have room to set the headstock up on my small mill to bore out if needs be.
It then struck me that if I needed to bore the headstock casting anyway, why not bore it to take roller bearings? I would need to "pin" and fix the top half of the casting but that doesn't look too difficult - famous last words?
Mark, Babbitt seems very expensive but when thinking about your idea I realised that I already have 80% of my needs anyway, assuming of course that this can be melted and reused. I know that would result in a "blend" but as Dave says close enough is good enough. I think like Fred and his piano I will have another cup of tea before I go and knock another wall down. Apologies to younger readers but your education is sorely lacking if you haven't heard about Fred and his piano.
Best regards
Keith
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jontom snipped-for-privacy@hotmail.com wrote:

So if we _have_ heard of Fred's piano, you're calling us old, right ?
-adrian
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Adrian Godwin wrote:

Adrian
No not really, only as old as I call myself, and I still feel young (sometimes). It might be more of a "slight" to your (or your parents) taste in music!
Regards
Keith
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wrote:

Veritably antiquated methinks.
Right said Fred Both of us together One each end and steady as we go
Tried to shift it Couldn't even lift it We was getting nowhere And so We Had a cup of tea and
Right said Fred Give a shout to Charlie Up comes Charlie from the floor below
After straining Heaving and complaining We was getting nowhere And so We Had a cup of tea and
Charlie had a think and he thought we ought To take off all the handles And the things wot held the candles But it did no good Well I never thought it would
Oh Right said Fred Have to take the feet off To get them feet off wouldn't take a mo
Took its feet off Even took the seat off Should have got us somewhere but no! So Fred said let's have another cup of tea And we said Right-o
Oh Right said Fred Have to take the door off Need more space to shift the so-and-so
Had bad twinges Taking off the hinges And it got us nowhere And so We Had a cup of tea and
Right said Fred Have to take the wall down That there wall is gonna have to go
Took the wall down Even with it all down We was getting nowhere And so We Had a cup of tea and
Charlie had a think and he said look Fred I've got a sort of feeling If we remove the ceiling With a rope or two We could drop the blighter through
Oh Right said Fred Climbing up a ladder With his crowbar gave a mighty blow
Was he in trouble Half a ton of rubble Landed on the top of his dome! So Charlie and me had another cup of tea And then we Went home
--
Dave Baker
www.pumaracing.co.uk
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Keith, You need to mark a register on the casting before you melt out the babbitt so you can make a true centred bore after casting new babbit. If the old babbitt is in good nick, you could add about 25% of tinmans solder to make up the quantity without losing more than about 4 or 5 points Brinell hardness. The chances of buying a small quantity of babbitt are very slim - when our company policy alowed the sale of a 3 kg bar it was over 50 quid ex works. You might find a garage that has a bit they are willing to sell left over from old engine days. To fit roller bearings could throw a strain on other bits - they are not so forgiving as babbit bearings if misalignment is an issue. Finally - if you go for casting the babbitt into the housing, as it is at present, you need to tin the housing first and cast the babbitt on to the molten tinned surface to get a good bond. Alternatively you could make the babbitt into half shells and 'araldite' them in. If you do that, an anti-rotation key or peg needs to be added for security. Phil
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Sounds like a pretty complex job compared to making a bronze bush and pressing it into place.
I have a few other thoughts which may or may not be of help depending on how the headstock is constructed.
1) If white metal shell bearings could be used then there's a good chance that there'll be something out there that fits from an automotive engine if the lathe shaft is a std size. I have the Glacier catalogue which lists the shaft size, housing o/d and bearing clearance for pretty much every engine ever sold in the UK. The clearance can be tweaked by filing the edges of the shells down a tad before fitting them.
2) In the USA they often repair the rear flange of crankshafts that the oil seal runs on by machining it down and shrinking on a thin wall hardened repair bush. Perhaps the same technique could be used here to adapt the shaft to a different bearing size and also properly suit a bronze bearing. This would eliminate any existing wear in the shaft as well.
3) On modern engines the camshafts usually run directly in the aluminium of the cylinder head and very little wear takes place on either item. High silicon aluminium is a decent bearing material for cast iron or steel shafts. I have a load of old cylinder heads knocking around which might provide the parent material for a bush to be made out of. It would help if I knew the shaft size we're talking about here.
--
Dave Baker
www.pumaracing.co.uk
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Dave Baker wrote:

Phil/Dave
Sorry for the delay in replying but "normal life" has again got in the way of enjoyment so I haven't been in the garage for a couple of days. Phil I have a couple of large bars of "solder" that I cleared from my fathers shed when he moved so I could dilute the remains of the Babbitt with that. Not sure if the original is in good nick though as it does seem to have a few "inclusions" that have been lapped into the bearing. I can machine that away but I suppose that will increase the dilution a bit.
Dave, the spindle is a nominal 1.5" OD but it has worn over the area of the front bearing and is now 1.494" and tapers slightly so will need re-surfacing to a slightly smaller size anyway. Thinking about various alternatives as you suggest, I had thought of trying some fairly thin two row ball bearings on the front with a little pre-load provided by a thrust washer against the rear face of the rear bearing which appears to be in reasonable condition. However this will require a sleeve to overcome the spindle wear and I'm not sure if it would be any better (easier) than a plain bearing.
Confession Time. I must admit that you have all convinced me that this could be done with a reasonable chance of success but, and there is always a but, I am not at all confident that I could make a worthwhile job of it. In the end I have given my friend a nearly brand new Emco Compact 8 that I was using for a bit of wood turning. He is over the moon and I am left with the problem of what to do with the Atlas. I certainly don't need it or want it. I suppose that someone might use the parts if I put it on the dreaded E-bay. On the other hand, I hate being beaten (or in this case giving up) if something is repairable and I suffer from this "engineering" affliction of "if it can be repaired it should be". Incurable I suppose. Having sorted the immediate problem of providing something for my friend, I guess the Atlas will go back under the bench waiting for that rainy day when I have plenty of time and am looking for an interesting project. Are we all the same?
Anyway, thanks to all for the suggestions I'm sure that many of them would have produced a very usable lathe. Apologies for not implementing them but I now know what to do just need to find the time to do it.
Regards
Keith
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If you'll permit me to persevere a bit longer I think, while perusing the Glacier catalogue, I've just hit on a bit of a brainwave. White metal camshaft bushes. These are one piece steel backed bushes designed to be just pressed into a bored housing. Much easier to design for than trying to fit two separate big end shells. There are hundreds of different sizes in the range 1" to 2".
In just a couple of minutes I've found a Fiat one for a shaft 1.495" which would fit nicely if the shaft was built back up with chrome and a Seat one for a shaft 1.485" which would just 'suit you sir' with the shaft ground down a tad to clean up the wear.
All you have to do is bore the headstock to size or make a mild steel adaptor ring which the bearing presses into and then fit the lot into the headstock if that is already much bigger than the bush o/d. Any wear and you just pop a new bush in. If you want more bearing length stack a couple together. They all vary in length and o/d but for example both the above two are 15mm long and fit into a 1.650" housing.
Anyway, I'll leave you to it if you're putting the project on hold for now but if you decide to go ahead again anytime we'll all be here no doubt.
--
Dave Baker
www.pumaracing.co.uk
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Dave Baker wrote:

Dave I'm ashamed to say that I enjoy discussing these types of problem as much as actually getting my hands dirty. I also find that I can learn a great deal and when I am eventually moved to get off my rear end and attack the metal it usually goes smoother if I have a good idea of what and why I'm doing it that way. Unfortunately with the design of the spindle (much like an ML7) I cannot get a solid ring to the front bearing location unless it is bigger than the 1.5". I like your idea of building up with chrome and re-grinding back to nominal. Obviously if I could use half shells then I don't have that problem and could go down a size. It's a long time since I ventured into the "innards" of an engine (rebuilding my Lotus Europa 20 years ago I think) but if the shells were similar thickness to the camshaft bearings then they could easily be accommodated within the thickness of the present Babbitt. The other advantage I see in half shells is that as you have said I could adjust for the last few tenths by cleaning up the ends. As an aside although I still play with kit cars, modern engines (Ford Zetec etc) are so reliable and cheap that it is much easier and cheaper to replace than rebuild. Of course this is only possible when any engine will do, for the car restorers and racers out there they still need to struggle to find or develop the old skills which seem to be rapidly disappearing. The one other concern I have is that these modern bearings perform with pressure lubrication although I guess the 1200 or so rpm with flood lubrication would not stress them too much.

That's one of the most impressive things about this forum, everyone seems happy to help and advise where they can and I'm sure that I have progressed more in the last year or so since I found it than in the previous 10 years. With the advice available I have finally settled on the lathes that I NEED and have started to enjoy using them rather than worrying about how accurate/new they are. I find the search facility invaluable and have spent hours reading many helpful posts. I have also learnt to "filter" out some of the less useful posts and had a good laugh at some of the others. My ability to spot a troll (not here of course) is also improving slowly. I'm also surprised by just how many people ask a question (presumably because they don't know the answer) and then spend two weeks arguing with the advice given - there is no accounting for folk.
Anyway Dave, I hope that you and the others who have the knowledge/experience will continue to answer the daft questions and ideas that the less knowledgeable of us pose (many times unfortunately). It is very much appreciated and I'm sure will guide many into this very enjoyable way to spend time (and money). I'm pleased to say that (I think this was said before somewhere) I'll definitely be back, just as soon as the next project takes me outside of my experience zone (tomorrow then). Thanks again.
Best regards
Keith
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In that case I'd go back to the sleeve idea and sleeve up to a convenient size of camshaft bearing bush or bronze bush. Cheaper than chroming and regrinding I would think. Loctite, heat shrink or solder/braze the sleeve in position, grind it true with a bench grinder mounted on another lathe and then melt all the old babbitt out and make the bush. Some of that 50/60mm alloy steel bar that Peter Neill is chucking out today would do you nicely for a sleeve then you can make your bush out of anything you like.
I'd rather spend a few hours boring, turning and grinding fix-on bits than trying to learn how to re-babbitt a headstock and end up in a bugger's muddle. If my soldering is anything to go by I'm quite sure it would be well beyond me. I reckon I could do the sleeve and bush trick though.
--
Dave Baker
www.pumaracing.co.uk
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wrote:

If Hoyt don't sell small (3-5kg) quantities of Babbitt any more, Who does? Out of curiosity, is this a minimum order thing, or some other reason?
Mark Rand RTFM
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If the shaft is unhardened (Brinell less than 200) there are only two ideal materials. The original babbit and aluminium containing at least 20% tin. However bear in mind that wear is a gradual process and if the machine is not going to get much use then a theoretically non-ideal material such as bronze isn't going to cause a major problem. There's a hell of a difference between something that needs to be used at full capacity 8 hours a day, 5 days a week and a machine that's only going to get switched on once in a blue moon.
With that in mind I think you could also consider a leaded bronze which is much more suitable for unhardened shafts than tin or phosphor bronzes. In fact taking this pragmatism to its extreme you could say that a few hours of use a year isn't going to be equivalent to even a month of full time industrial use for the rest of the machine's lifetime and that any material that falls conveniently to hand will do the job. The owner will probably die long before the shaft or new bearing do.
Your other option is to hard chrome or tuftride the shaft which will let you use just about any bearing material you can find.
--
Dave Baker
www.pumaracing.co.uk
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Dave Baker wrote:

Dave, thanks some great thoughts there which certainly increase my confidence no end. I have several pieces of "dubious" bronze that would do the job (in size anyway), but they range from a very yellow colour (not as yellow as brass) through the more normal "bronze" to one that has an almost blue tinge. Does the colour give any idea as to the composition of the material? Would I be better getting the hardness tested or is there another way to "roughly" identify bronzes. I also have some very soft Aluminium so perhaps I should machine a couple of short test bushes and run some mild steel bar in them for a couple of days and see the result. I assume that a "leaded" bronze will machine better than "tin" so perhaps I will just go with the best machining bit I have.
I think I will try re-metalling the current bearings as a trial and then if I b***"*ks that up (highly likely) then I have the safety net of your suggestions. As you quite rightly point out the usage my friend is likely to put the machine to in the next 10 years would not equate to a months running in "proper" use. As I will need to re-bore and scrape in all options any idea what size I should bore as a start before scraping - shaft size plus .001"?
Thanks to all for your replies and suggestions, I now have a way forward that allows for at least one "co*k up" without it being totally unrecoverable. Happily it also appears that the cost might not dig too deeply either. Ah well, enthusiasm topped up, Monday tomorrow, wife going back to work, machines oiled, empty and waiting; what more could I ask for. Retirement is not all bad.
Regards
Keith
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