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Oliver 25B bearings running hot

John Hal

Plastic
Joined
Mar 30, 2019
Hi, I purchased an Oliver 25B about 9 months ago and finally have it under power. However, the headstock tapered roller bearings (Timken are running hot (too hot to hold the adjacent casting after 15 minutes at approx 1200rpm). It sounds smooth but sounds like it's working too hard.

It could be one of a few problems to my understanding:
-wrong viscosity of grease
-bearings over packed
-thrust nut over tightened
-bearing misalignment

Also:
-I am not equipped to remove the bearings and shaft which means I can't clean or replace them properly (and ensure grease incompatibility)
-I've removed the purge plug from the outboard bearing housing and the cover from the front bearing and run the lathe using centripetal force to get rid of most the old grease

Any advice out there?

-Is there a way of flushing the bearings without removing them? (whilst neutralising the solvent used before putting new grease in)
-What's the best way of semi-repacking bearings still in there housing
-how do I ensure the correct force/tension on the thrust nut?

Failing that, does anyone know how to remove the bearings without screwing up alignment, concentricity etc?

NOTE:
-The 25B is a direct drive machine i.e. the spindle is the motor shaft.
-The motor also appears to be friction fitted to the inside of the headstock casting (real weird) which makes the headstock an incredibly tight space to work inside.
-I can't see or access the inside faces of the bearing.
-Nor can I access the outside face of the outboard bearing because the outboard cast cover plate will not come off.
-I am very cautious of messing this thing up because of the difficulty in working around the direct drive system- I can't afford to damage the motor, bearings or casting.

Please Help!

Thanks,

John

1.jpg2.jpg3.jpg4.jpg5.jpg
 
I think I would check the lateral thrust of the bearings first, it sounds as if someone may have tightened to much. You will need to use a magnet base with a .0001" or at least a .0005" dial indicator to test this the right way. Might cost you on Ebay around $100.00 for a combo for a Chinese combo.

This is conjecture as I am trying to help with out being there and don't know your skill level.

If you can't afford one loosen the spindle approx. 10 degrees of the nut. If you have a mag base indicator loosen the nut 90 degrees and tap the spindle loose, opposite the spanner nut. Then tighten it 10 degree's and put indicator on spindle front and with .005" pressure push the spindle and check reading and tighten and check slowly until you have zero slop or backlash. Then tighten the spanner nut 10 degrees. The spindle should be tight and Timkens need a preload. As far as cleaning the bearings.

Only one time in 50 years of rebuilding can I remember not pulling a spindle to flush the grease. It was on a Hardinge and we had a air sprayer with a screw on quart canister we put mineral spirits in and put on a cap and face shield as it was a messy job. The grease was 30 years old and hard as a rock as the machine had been in government storage and never used. The customer didn't want us to pull the spindle. After we cleaned them we used a syringe filled with Mobil #32 red horse grease. Replaced the drive belts too. Put the covers back on and ran it. Never heard back from the customer. In my business new news is good news. LOL I find it hard to believe 1200 rpm would make it get over 120 - 140F degree's (when it is to hot to touch) I was also thinking the motor could be wired wrong or the stater is shorted. Have to be a detective and after you figure it out please come back and tell us. Oh and be sure to buy some good industrial grease and not something you buy at a hardware store. Rich

PS: Only fill the bearings to about 30%. To much grease will make bearings get hot. But usually the RPM is around 2000 where I see heat issues.
 
John,

The pictures show lots of nice fresh grease....way too much in my opinion, and too much can get things cooking in short order. Before I ripped things apart I would pull any cover over the bearing cavity that's easy to pull and wipe out as much grease as I could. I would then use some brake cleaner with an extesnsion tip and blow as much grease as I could out of the bearings, letting them dry overnight.

I would speculate those bearings need no more that 30% fill to operate correctly, and that's not a whole bunch.

Stuart
 
Lots of SALES related, but little if any TECH help

Oliver Machinery Co. - Publication Reprints | VintageMachinery.org

So, it will be up to you

Its only a machine - study it. It went together, it must come apart.

A first step on the left end would see about getting ALL off BEFORE the cover you want to pry on

Second photo post #1 above.....then pdf page 4 under Head Spindle in link below

http://vintagemachinery.org/pubs/609/291.pdf

Says that plate (for outboard face plates) is SHRUNK on spindle - so that is a rather formidable barrier to get off prior to cover you want to pry on. None the less, that is how Oliver did it
 
Just a perspective:

The headstock bearing on the Weiler LZ330 I have is designed to be adjusted by assessing the temperature rise of the bearing and headstock after a period of time running.

I found it interesting to note that the temperature was quite high, 80C IIRC and the adjustment was in the bearing preload when using the prescribed grease.

It may seem a bit trivial, but if the bearing is not completely sealed, overheating will cause the grease to run out. In a way, self correcting.

I suggest running the spindle at around 700 rpm for several hours, then ramp up to the 1200 rpm over several steps and several hours for each step.

Of course, if you can slack off "the big nut" one flat, everything might fall in place in short order.
 
I have a 25a (same headstock, no riser underneath) and a manual and I believe parts explosion of the headstock. I can email you some pictures if you send me you address.

Peter
 
Richard, They generally don't post Oliver manuals in respect to Rich Fink at Eagle who stills sells them. I have a couple for the machines I own, and an amazing catalog that I picked up on eBay a number of years ago. It is circa 1950 and it is a bound collection of all their sales Brochures. It;s very complete and has their more modern machines unlike the old hard bound Catalogs, would be a bear to scan as it is over an inch thick!

Pete
 
I dont know if you have seen this or if it will be relevant to you but I have found this to be the best video describing the process of preload. He is a forum member and a very talented person. This may not be relevant to your machine but it is well done and worth the watch.

YouTube

Charles
 
Pete mention Rich Finbk at Eagle Machinery, he is the man to talk to about this. No one has more experience or knowledge about Oliver machines.

Eagle Machinery

I have a 25C which I love. They are so smooth and accurate, a real pleasure to use. Yours looks very clean and well equipped.
 
It all comes out the outboard end. I was told they didn't build them with any consideration to how to take it apart later.

I just rebuilt one of these head stocks.

Have to pull rotor to replace outboard bearing.

Sent from my SM-N960U using Tapatalk
 
Mr Green, can we assume that it was necessary to press off the outboard hub to get to the outboard bearing? If so, how did you do that?
No, it all comes off the inboard side. Nothing comes off out board end, other than sliding entire thing out of the head stock that way. To get to the out board bearing you have to pull the rotor off.

Sent from my SM-N960U using Tapatalk
 
oliver-25 - 1.jpg

Here is the cross section of the headstock. You can see clearly what Mr G is saying about it all coming out the back. you have to pull the rotor off of their joiners and planers to get them apart as well. Isn't too bad a job, especially if it only needs doing every 50 years or so.

Pete
 
View attachment 254661

Here is the cross section of the headstock. You can see clearly what Mr G is saying about it all coming out the back. you have to pull the rotor off of their joiners and planers to get them apart as well. Isn't too bad a job, especially if it only needs doing every 50 years or so.

Pete
Other than it's a really heavy assembly, have to be careful with the windings and you will need a long reach heavy duty puller to get the rotor off.

It's a days worth of work and about 180 bucks worth of races and bearings.

Sent from my SM-N960U using Tapatalk
 
Yeah, I recall welding up a special set of jaws for one of my pullers when I did my Oliver planer.

Richard, It's definitely been too long!

Pete
 
John
The Rotor on these motors are long and heavy. It would be easy to have the end drop down and damage the windings while you are trying to slide it out.
You would not that to happen it would be very expensive to have the stator rewound.
I would suggest making a long support tube to fit on the nose of the arbor to use as a support as you slide the assembly out by sitting block of the proper height on the inboard side of the lathe. If you have a steady rest that may work or you may be able to adjust a tool rest to the proper height.

Good luck with this
Ron
 








 
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