Shielded Bearing Evaluation - Cleaning/Regreasing

Hello,

I've recently picked up a 9 inch Logan bench lathe (9B-28-1) and am working through making it usable. It doesn't have any markers of being particularly worn, but it sat for about 15 years before I got it. Before it sat, someone bothered to coat it in grease, which has now hardened to a flaky crust, but all the important bits show no sign of rust or corrosion.

The spindle rotates, and I can't feel any deflection, nor are the measurements significant, but the spindle "settles" into the spot it had been resting in for years. When you spin it a few times by hand, you can't feel the bump or sticking, but it does feel a bit like you have to move some hardened grease out of the way to get it going. I use a Logan at work and it has a smooth action when you turn the spindle by hand.

Considering this is a Logan, with the specially pre-loaded bearing, I'd like to salvage it if possible, as I can't afford the cost of a new bearing.

Is it possible to clean and regrease these bearings? If I remove the shield to do so, do I risk much harm by putting the bearing back into the machine without it? It's fairly well tucked into the headstock casting. Am I evaluating it incorrectly in the first place? I didn't want to run it with the hopes of warming it up and moving some of the grease around, in case it really was dried out and I was going to damage the bearing more.

Edit: I just realized this might not be acceptable content for this subforum, but I'm not sure where would be more appropriate.

Don't know if it's similar to my 211, but in that the bearing is unshielded. I think shield(s) slide on or press on the nose. If yours is similar, definitely pull it apart, clean it and regrease it. It's a slow speed machine so you don't need a fancy expensive grease. Get some Chevron SRI.

Thanks Conrad, but unfortunately the bearings are like those shown in this post: Logan 4. Headstock. | The Hobby-Machinist Forums

I appreciate the tip on the grease though, wasn't sure what I was going to pack back in it once it's cleaned.

No guarantees but I once dribbled a half dozen drops of three in one oil into the bearings of a Logan 200 to soften the grease. It ran smooth after that. Worth a try if the alternative is bearing replacement.

You should be able to remove the spindle/bearing assembly and maybe expose the bearings enough to relube. One thing you don’t want to do is remove the front thrust bearing from the spindle. Easy to damage that way. The rear bearing should come out with the right tools

Shields will be a problem, but the recommended way to clean bearings is to soak them a solvent such as Stoddard solvent, rinse and repeat until the solvent comes out clean. I like the idea of putting the bearings and grease in a plastic bag and pulling vacuum. When reinstalling the bearings, check for how they should be assembled, as in the thrust direction. Check on line with bearing mfr's for the correct orientation.

Tom

Maybe the bearing will have shields held in with snap rings. In any case, it would be nice to get it cleaned out and regreased. Even my ancient one runs pretty nice after cleaning and greasing.

Could you show us how you do it? I’d like to see. We see so much about replacing bearings, I’d like to see what regressing Logan bearings involves.

I wonder if you're sure it isn't the belt, they get a set when they sit and try to go back to where the set is?
Dan

Hi Dan,

It's not the belt, as no belt was installed at the time.

I've since removed the spindle, and the same feel exists outside of the headstock. I'll have some time to evaluate the bearings further tonight.

Mach2, if I end up cleaning and reusing this set, I'll document it.

It is probably a double row bearing, internally preloaded by ball selection. Bith ways loading is identical, in general, but it should have a snap ring that makes it fir only one way.

being double row (in one piece) it can get to be an issue to remove all the old separated grease. I did not succeed, and had to replace mine. Logan did not then know about the preload, and sold me one with clearance, so it was a disaster, and I eventually preloaded it externally.

I never have been able to remove the grease from the old one. Nothing seems to dissolve the lumpy coagulated "soap" used to make the grease.

Naphtha, soaking, brush with long bristles, soap and hot water with the sprayer at the kitchen sink, compressed air (don't spin it). A combination of those things, repeated several times, got mine clean.

That sort of treatment did NOT clear out the congealed "soaps" from the grease in mine. Might try it again sometime. My old one is very unlikely to be worn or bad, just crudded up with grease crap.

So I've got them rolling freely after a soak in mineral spirits, but there is clearly some crap in there that doesn't want to come up with repeated flushing. They spin, but some grit or chip is floating around inside.

That said, this is a single row bearing New Departure 773L08, which doesn't seem to be carried by Logan Actuator, nor does it seem to be a special bearing with preload, unless I'm mistaken in thinking that a bearing with preload would have little axial play between the races.

Would anyone know if the 9b Logans used a simpler bearing setup than their heavier brethren? Modern examples of that bearing seem to run about $15, and NOS Delco/New Departure seem to run the same.

Hmmmmmm.....

Were there more than one of 'em?

Are there any belleville springs? Some Logans were made with single row opposed, preloaded with Belleville spring washers.

I believe JST is referring to 800/1800 series lathes in post 10. The 10” 800/1800 series used double row angular contact bearings and were preloaded at the factory. I don’t believe bearings from the 800/1800 series lathes will fit your lathe or the 200 series 10”. The 800/1800 and 200 series lathes had different spindle outside diameters along with different bearing setups, the 200 series having a smaller diameter spindle. I have no experience with the Logan 9 but it might be helpful to post the physical bearing dimensions; id, od and thickness from your machine for comparison by someone with a Logan 200 series.

No experience with ultrasonic cleaning but have you considered that possibility?

Yes, the 200 series had double row. Some others did also, but I don't know which.

Also correct on the spindle size, as far as OD. Not sure if the larger size used double-row though... I had thought that was where they started using the preloaded opposed single row.

You could ask Scott Logan which has what, and if there are bearings available for that machine if you cannot get them cleaned.

Frankly, I doubt any of them are actually "worn out"... The double row have a rating of something like 4 tons, and never saw anything remotely close in the machine, the single row are probably similar. With that sort of derating, they will probably run nearly forever unless damaged by crud getting in. Wash the heck out of them, and then see.

I would have re-used mine, if I had been able to get it clean. It's probably still much better than the POS I actually got from Logan at the time (they have good ones now). But being double-row and half-shielded, I just have not been able to get out all the old grease. It's still bumpy and lumpy.

Sorry for the delayed response here. I ended up getting NOS bearings and will be using those. They roll a little stiffly, but smoothly, and I can see that the grease is intact and unhardened. I don't have the facilities to properly clean whatever is in the old bearings out, no ultrasonic, or parts cleaner, etc...

For future reference, if someone else is working on a Logan 9B - they are not double row bearings. They are not specially preloaded. They are preloaded with the assistance of the spindle nut and belleville washers on the rear side. This pulls the front bearing against a stop on the spindle itself and takes up any slack. I will follow up with pictures. I don't think this is the most common Logan lathe, but they still must have made thousands of them, so eventually someone will have my questions.