Timken bearings or Babbit?

ShagDog

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Looking at an Atlas lathe 10" and trying to figure out if it has Timkens or babbit headsotck bearings. The serial # is D5511 S, if that says anything, maybe at least a year? If it is babbit, is it relatively simple to switch to Timkens? If not timkens, anything wrong with babbits?
 
Nothing wrong with babbitt, I owned one and liked it. Babbitt is an issue if it is worn out, because you cannot convert bearings directly. I had a Timken head I rebuilt but never installed because the babbitt head was true and smooth.

The easiest way to tell the difference in a photo is by looking for the bearing cap bolts on top. Babbitt heads are made to be shimmed down as they wear, so the caps come off. Timken heads have no bearing caps or bolts, the bearing cartridges install in bores.
 
To my knowledge, the conversion is not practical from babbit bearings.
Babbit bearings are preferable for woodworking, but metalworking is best done with roller bearings
Babbitt is pretty hard, lots of tin in it. It's a bearing, after all. Having run both, I'll say the babbitt is smoother and quieter and gives a better finish. The Timken head is stronger and deflects less, but sounds like a runaway skateboard on a rough road when it runs compared to the babbitt. Timken rolls with noticeable but negligibly less resistance. Twenty four little balls have to roll on a squeaky clean surface in order not to jitter, all else being equal. Wick fed open-case bearings in a total loss system isn't what I'd call squeaky, it's a dirty environment for those bearings, the open case was designed for Babbitt, which can only be contaminated by means of the oil, and retrofit with bearings that have access to the belt, sheaves, and back gear's drippings.
 
As far as no muss no fuss the roller bearings win. A babbit setup that's badly worn is a nightmare to rebuild since it may involve a new spindle.
Roller bearings can be adjusted for zero runout by just making one simple adjustment- piece of cake compared to babbit
I recommend beginners stick with roller bearing headstocks
-M
 
but a babbit setup can be more accurate and quieter .. (no balls or rollers moving). A well maintained babbit can be a super accurate machine.
 
I agree, once the babbit is out of round and out of adjustment shims, it's done. Pouring babbitt may not be black magic, but getting and keeping alignment during the job is beyond benchtop resources. You would have to be one committed individual to pursue that feat, and the Atlas lathe budget would be blown out of proportion badly by the time you were done.

Babbitt heads show wear in the direction that work deflects when you feed the tool inward. Because of the factory installed shims, they tend not to show nod at the chuck face until the very end of their life. Use a convenient piece of stock and a dial indicator to see if it is prone to excessive deflection in that direction. Bring a 9/16 and pull the bearing caps too. If there is even one shim left, it's looking good. If it's a Timken head, this discussion is moot. The difference in function is trivial.
 
I have an older (1916) Seneca Falls lathe that has babbited bearings in the headstock. It's still running true, but when the time comes (if I'm still around) I wouldn't hesitate to repour them even though I've never done any in the past. Personally, I think it would be fun challenge and a great learning process.

The company I worked for had several ancient (circa 1910) ammonia compressors for refrigeration. They ran 24/7 keeping production rooms, coolers, and freezers operating at the correct temperatures. They were serviced on regular intervals which included rebabbiting the flywheel bearings every 5 years. When the time came the 12' diameter flywheel was hoisted out of the pit and the millwrights went to work. They melted out the old babbit, out of the 8" shaft pocket, put in dams to retain the new material and began the pour. Pouring was the easy part. Scraping to size was where the skill came in. The job was finished, and the flywheel was usually reinstalled within a 2-day period.

The compressors were a joy to watch. The huge flywheel probably spun at around 60 rpms pumping ammonia through several miles of refrigeration and freezer coils. Not only was the system efficient, but it was also extremely cost effective. Unfortunately, there was a powerhouse fire in the late 1990's that destroyed the compressors. Since they were nearly 100 years old no replacement parts were available, and the cost of having them made was prohibitive. They were replaced by more modern (and far noisier) screw compressors. Rather than hearing a methodical thump, thump, thump throughout the day we now had something closer to a screaming banshee to contend with. The company spent several hundred thousand dollars to add sound deadener to the compressor rooms.
 
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Thanks for all the responses. Looks to be babbit bearings, based on the bearing cap bolts, per Pontiac428. Interesting discussion by the way.
 
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