Grease or Oil in Old Lathe?

[Larry C in Auburn, WA]

I have my Dad's old, old lathe. Gawd it's heavy!!! My question is it has Babbitt bearings (I think that's what they're called) so do I use oil in the reservoir or do I use grease? It has about a 1/4" fill hole that gets covered with a machine screw if that provides a hint. My Dad is long gone and of course there's no manual or any info on it. Is it typical that one or the other gets used or does it vary among machines?.

I guess the second question is I put oil in it to get it going and because I didn't even think of using grease until my wife's Uncle suggested I should have used grease. Any great suggestions for getting the oil out without tearing the thing apart or do I need to worry about it and just pump it full of grease (if grease is the right choice and not oil)?

Any help any of you can provide would be appreciated as I'm out of my element here.

[Unisaw A100]

I don't do babbitts so I can't say for certain which oil is best/allowed but you can/should Google the archives on the OWWM site. Lots on babbitts there.

owwm.com

UA100

[Tom]

I have an old 1960's craftsman-atlas metal lathe. I've always (and my dad before me) used regular 30w motor oil to fill the bearing reservoirs, and no problems. Instead of machine screws, mine has a spring loaded cap. Unless the thread is the same for a grease nipple, I'd say use oil.

[Phisherman]

The best thing to do is follow the Babbitt recomendations for maintenance. Actually, that goes for every piece of equipment. I use a combination of lubricants. When grease is recommended, it is usually lithium grease. Oil is very short term unless it is enclosed in some kind of housing. For cleaning off old crud, I use kerosene and the Mother-in-law's toothbrush.

[George]

Oil for sintered bearings. The recommendation for 30 weight is probably enough, but you will want a non-detergent oil for best lubrication. That may kick you up to a bit heavier stuff like 50 gear.

Does it have wicks?

[CW]

Use oil. The way a babbitt bearing works, grease would leave it running dry.

[Dave Fleming]

Oil it is. Non-detergent at least 30 Wt. I wouldn't be a bit surprised if there were not a few BABBITT sites out there. FWW may have an article or two on Babbit Bearings either in a back issue or one of the books on restoring/rebuilding woodworking machinery. AND as 'keeter' mentioned the OWWM web site is a font of knowledge on 'old arhn'. Tales of a Boatbuilder Apprentice

[CW]

Babbitt is not sintered. You are correct however that a non detergent 30 weight would be the way to go. Most autoparts stores carry it.

[Larry C in Auburn, WA]

Thanks for the help guys! As always you've given me good info. I did DAGS and looked at OWWM before posting, but couldn't find an answer. It might be out there, but after about an hour of very interesting reading I still hadn't found the answer.

The shaft is enclosed in a housing, but I'm not sure how the oil gets up to the shaft which is at the top of the housing. It's 5 inches from the bottom of the housing to the bottom of the shaft. How does the oil get to the top or do I have to ensure it's always completely full of oil?

[George]

Friend of mine was an oiler in the boats on the great lakes. He went round and round, filling the reserviors....

[George]

He thinks, therefore I don't know. Nonetheless, if they were sintered bearings a non-detergent oil would be more important than with lead.

Sintered bearings usually have oil wicks, thus the question.

[Ian Wheeler]

Typically Babbit bearings like these are 'Oil Ring' lubricated. A ring (usually Brass or Bronze, maybe Iron) about 2 to 2.5 times the shaft dia sits on the shaft, the bottom of the ring dips into the oil several inches below. As the shaft turns, there is enough friction to let the ring spin with it; then it picks up the oil and drops it on the shaft, where it spreads out into the bearing.

If this is an oil ring bearing and the ring is missing - it won't last very long. Also, if the oil level is to high it will fail. The oil level needs to _just_ cover the inside surface of the ring at the lowest point, any more and the oil will cause more resistance to rotation than the shaft friction creates, then the ring doesn't turn. Another issue, it's been a long time since I last worked on Babbit bearings, so I can't remember the oil viscosity numbers, but if the oil is too thick is puts to much drag on the ring as well.

It's possible that the bearings are lubricated some other way, but if the level is so far below the shaft it sounds like oil ring lube to me. If there is an access hole (plugged or with a spring loaded cap) directly above the bearing, you may be able to see the ring in there sitting on the shaft. If you can, it should run very smooth, any bucking from side to side or skipping indicates to high an oil level or to thick oil. If it's bone dry, then the oil level is to low.