Warco WM250 headstock lubrication

[Mark P.Participant @markp]

[Mark P.Participant @markp]

Hi all,has anyone fitted a headstock lubrication system to a Warco WM250 lathe? Because the only way to lubricate the two taper rollers is to dismantle the whole spindle assy,which is far from satisfactory.I have a pair of drip feed oilers which I was planning on fitting but………………the way the bearings are fitted seems to preclude this idea.Any thoughts welcome.

Regards Pailo.

[MoosEParticipant @moose]

The WM250 manual leads one to bbelieve that the headstock is lubricated from the gearbox below. Not the case! I agree with Pailo there is no easy way to lubricate the bearings apart from dismantling. Leading on from this: My machine is about 18 months old and recently after working it for about 1/2 hour at full speed, the spindle rapidly decelerated accompanied by an awful noise as the motor struggled. Switched off quick! The whole headstock was very hot and the spindle extremely stiff to turn.

On dismantling, the split spindle adjusting nut was unbelievably tight and its two lock screws had not been tightened sufficiently to properly lock it. There was very little grease on and around the bearings. So, failure caused by excessive pre-load and insufficient lubrication?

The chuck-side bearing has a wear mark on the outer race (dark ring in photo 1) and a corresponding mark on all the rollers suggesting point contact and an error in the bearing tapers. Anyone else seen this sort of thing before?

 

Cheers,

MoosE.

Edited By MoosE on 07/11/2011 23:40:58

Edited By MoosE on 07/11/2011 23:44:56

[Chris TriceParticipant @christrice43267]

Well, I don’t think anyone will seriously argue that far eastern bearings are a match for good quality branded bearings. You can feel the difference. You get what you pay for.

[adyParticipant @ady]

All these new units need to be stripped and checked before use.

Some of the overseas places have…um variable quality control.

 

And after saying that…I must admit that as a newbie the last thing I would want to mess with is tapered roller bearings.

[TerrydParticipant @terryd72465]

Posted by Chris Trice on 08/11/2011 03:23:30:

Well, I don’t think anyone will seriously argue that far eastern bearings are a match for good quality branded bearings. You can feel the difference. You get what you pay for.

 

Hi Chris,

 

I thought that Japanese stuff was considered high quality and they are from the ‘Far East’. Am I mistaken in either of those thoughts?

 

Regards

 

Terry

[Chris TriceParticipant @christrice43267]

Yes, very good. You got me there. Fortunately, everyone else knows what I mean.

[Chris CourtneyParticipant @chriscourtney72250]

I believe that all (or at least most of) the major bearing companies have manufacturing factories in China (not to mention India and Brazil), so that good quality branded bearing may well have been made in China.

 

By buying a branded bearing, you are getting a bearing manufactured to a known standard and quality, backed by the reputation of the company. In this day and age, where it is manufactured doesn’t necessarily tell you much about the quality.

Chris

 

[Chris TriceParticipant @christrice43267]

True but in general terms, the meaning of my statement is understood. SKF’s plant could be anywhere but I’ll wager the bearings aren’t made out old railway rails and go through a proper hardening process. I bet their taper bearings don’t contact on just one narrow band either.

[KMPParticipant @kmp]

Moose Hi.

 

Difficult
to be precise without actually seeing the bearing but I doubt it is
poor manufacture, rather it appears to be a classic “smearing” failure
from your pictures. Obviously could be caused by a simple contamination
problem but is mostly caused by poor assembly technique, particularly as
it has run for 18 months or so. Basically the bearing is assembled with
the two races slightly (very) misaligned. The excessive pre-load is
applied without rotating the bearing causing the races to fail to align
correctly and the rollers to be extremely tight at one point and fairly
loose on the opposite side. The rollers then constantly slow down (loose
area) and rapidly accelerate and skid (tight area) leading to the type
of failure you have. The problem is quickly exacerbated by lack of
lubrication. It is sometimes noticeable by a slight tightening as you
rotate the shaft by hand but not always as it is easily hidden by the
drag of other parts of the drive system.

 

There
is a good explanation of failure modes of roller bearings produced by
SKF and will easily be found with Google if you have the odd hour to
waste.

Best regards
Keith

[MoosEParticipant @moose]

Hi Keith,

Thanks for the detailed explanation.

 

MoosE

[Gunnar MParticipant @gunnarm]

Hi MoosE!

I have a problem simelar to yours. I have removed the spindle from the headstock, but the rear bearing is so tight on the spindle. So i haven't any possibillity to know how mutch force i put on the bearing when tighten the nut. Was this similar on yours?

Gunnar

[MoosEParticipant @moose]

Hi Gunnar,

I had exactly the same difficulty. The drive-side bearing inner race was so tight on the shaft it was impossible to "feel" for it tightening and consequent risk of further damaging the bearings. I carefully eased the shaft down with a strip of fine abrasive cloth, cleaned and oiled the shaft and re-assembled. Much better!

Did your bearing race and rollers look like those in the picture above?

I couldn't figure out how to remove the outer races without damaging the headstock casting so had to put the original bearings back. Used molybdenum disulphide grease (Castrol MS3) and the machine has since done a considerable amount of good work.

Cheers,

MoosE

[JasonBModerator @jasonb]

I had a very hard job getting my 280 spindle bearings out when they suffered the same fate. Managed it in teh end and did get the outer races out of the head.

Fitted FAG bearings and it runs so much smoother now but still could not easily judge the load needed to tighten the bearings.

J

[DoddyParticipant @doddy]

How easy was it to remove the bearing outer race from the headstock casting ?

[JasonBModerator @jasonb]

Easier than getting the spindle out and the bearing off the chuck end but still not easy. I cut a bit of 1/2×1" to bear against the back of teh bearing shell, drilled the middle for M12 clearance and then used another bar against the outside of the head casting and then would it out with a M12 stud down the middle, still needed a lot of effort.

Anyone thinking of changing the bearings on one of these type of lathes would do well to have a look at this article on Arc Euro's site, there is a sketch of how to make up a puller to get the spindle out

J

[Gunnar MParticipant @gunnarm]

Hi MoosE!

My bearing wasn't damage like your. I get more and more scattering when i use the lathe. So i tighten the nut on the drive side. It was realy difficult to tight it, use a lot of power before i get any change on the bearing. So when i start again it go well for about 30min. Then the bearing get a littel heat and i get a biggere resitens when turning the spindle. To loosen the bearing again it was so hard that i made a ters. It then get to loose so i was forced to remove it complete. I then do it same way as you, used a abrasive cloth. So i will mount it tonight and try again. Tank you for advice.

Gunnar

[KWILParticipant @kwil]

Just to put this all in context, I used a 5Ton hydraulic ram in a specially made jig to remove and refit simlar (larger) bearings. The final set up was done by measuring the rotational torque once the bearing was up to running temperature. I left the bearing fit on the spindle as per manufacturer. (damn tight).

[JasonBModerator @jasonb]

Thanks KWIL, I'll know where to come if I have to do it again, hopefully not for a long time and I also added a grease point so I can pump in a bit now and then.

J

[KWILParticipant @kwil]

Jason, there is a photo added for your dilectation.

[JasonBModerator @jasonb]

A very elegant solution, good job I didn't take any pictures when I did mine as the design was based on that of Mr Robinson.

You have also saved me some money, I had always fancied a M300 but if the bearings still need replacing like the far eastern lathes I'll stick with what I've got for now

J

[Sub MandrelParticipant @submandrel]

When I fitted roller bearings to my lathe I was distressed at the absence of information on pre-load. I eventually found some guidance and have had no trouble since. I note that the bearings on my lathe are much bigger than those on a typical family car, which are good for 250,000 miles with no extra lubrication.

Neil

[KWILParticipant @kwil]

They did not need replacing, the M300 oil seal is a open cap which allows the oil to drain directly back to the gearhead, however the seal between the cap and the headstock had a small leak which necessitated removal of the cap and that necessitates the part removal of the spindle to the right, to gain sufficient clearance to make the seal good. Original "super-gamet" bearing still in use.

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