|Bob Stevenson||10/05/2021 16:32:01|
|514 forum posts|
I have a Warco supplied WM180 which I have owned for three and a half years. For those who don't know this lathe it's the smallest of the 'WM' lathes made apparently by the Weiss factory in China and supplied world wide to many suppliers including Warco and two or three other UK companies in different colours and model names.
This lathe is well equipped with 'oil ports' on slideways and leadscrew mounts etc and I oil these frequently as laid out in the sparse owners booklet. There is almost no mention of the main headstock bearings other than a small paragraph pointing out that they were adjusted in the factory and that increasing the end loading excessively can damage the bearings.....
Because of the readily accessible oil ports I not unnaturally assumed that the headstock had sealed or shielded bearing which require no lubrication by the user.
Over the last year or so there has been an ominous rumble developing when the lathe is at speed and when the chuck is turned by hand one can feel a distinct 'texture' rather than a freely turning bearing.
The spare parts list/drawings gives the bearing as '30602' and this is a conventional taper roller bearing such as you might find in the front wheel of and older car. A washer against both bearings are listed as a 'grease cover'. There appears to be no means of re-lubing or greasing the bearings other than a complete strip down and knocking out the bearings from the casting.....
Replacement bearing of reputable brand are between £15 and £30 a pair and I am quite prepared to carry out a bearing change,...but frequent bearing lubrication seems to not to have occurred to the 'designers'....
I wondered how other users and those with the larger 'WM' lathes have got on with headstock maintainance....??.......anyone got any observations please?
984 forum posts
I have the WM250 (2007 vintage) and like you could find no mention in the manual of main spindle bearing lubrication. As there is no way to get at the bearings I also assume that they are sealed for life. Mine are still fine but definitely not over-used. The definition of 'life' is of course somewhat open to interpretation.
I shall just keep going until either the bearings fail or I do...
|444 forum posts|
Good afternoon Bob,
Seems to be the same for my WM250. I don't particularly like the idea of "sealed for life" taper roller bearings. Not sure how you would reliably seal a two part adjustable bearing assembly?
Have you tried adjusting the bearings as suggested in the sparse and pretty useless owners manual. Not sure about the WM180, but my manual is several iterations out of date.
20637 forum posts
My 280 was a very early model and a few suffered with dried out bearings including mine after a couple of years use. I had similar symtoms and the headstock also got warm.
Changed them for FAG bearings and greased them when I fitted them and they have not needed any further grease or adjustment in the 10plus years since.
|Mike Woods 1||10/05/2021 18:22:25|
|40 forum posts|
I suppose you could sum this up with a question - how often do you lubricate the wheel bearings on your everyday car? They are packed with grease on assembly, the car is driven until play/noise is detected then the bearings are replaced. The only problem here is the variable quality control we sometimes see evidence of in these Chinese manufactured hobby lathes which may affect the service life of the bearings. Correct pre-load, correct quantity or quality of grease etc. Maybe some parallels here with some of the cars from a certain era.
I have a Chester 920. Like others here, there is no provision for lubrication of the spindle bearings. It runs fine, makes no untoward noises and no discernible bearing play. If it does start to show adverse signs, the bearings are cheap, readily available and fitting is not too difficult for most.
A pal of mine has Chinese manufactured1326 size lathe on which the spindle bearings are splash fed with gearbox oil and now he has fixed the numerous oil leaks from poorly designed/manufactured sealing arrangements on the gearbox controls, no longer requires routine topping up. Almost a maintenace free system now and no longer regarded as a Torrey Canyon.
|Bob Stevenson||11/05/2021 07:55:31|
|514 forum posts|
Thanks to all respoinders so far!......your thoughts and experiences are very interesting.
Mike,...."how often do you lubricate wheel bearings".........When I was involved with 'vintage' Volkswagens I repacked and adjusted the front wheel tapered roller bearings every 6 months or so. although the bearing was much the same as in the WM180 it was completely different in that one could readily look and indeed examine the bearings. The point about WM bearings is that one cannot even know how well lubrication has been carried out or even what lube has been used, quite apart from complete ignorance as to the quality of the bearing used,...without pulling tghe whole lathe apart!
......Some decent design whould not have been amiss I think...(?)
|Niels Abildgaard||11/05/2021 08:09:10|
|395 forum posts|
Earlier South Bends and their Boxford copies had Stauffer cups for grease.
When Boxford went underdrive they changed and called it sealed for life bearings.
It was basicly the same old arrangements of discs with 0.2mm clearance around spindle and better grease.
It should have been named greased instead of sealed for life but British marketing at that time was say a little dubious.
The solution to day is to pull the spindle out without removing the cups ,unless they can bee seen to be damaged,apply some quality grease, assemle and do not worry anymore.
Edited By Niels Abildgaard on 11/05/2021 08:11:01
Edited By Niels Abildgaard on 11/05/2021 08:12:04
7229 forum posts
Bearings, and why they fail, have been much researched. Sealed roller bearings outperform other types - last longer and are more reliable. The problem is dirt. Open bearings are extremely vulnerable to contamination resulting in rapid wear. Open bearings need frequent maintenance, and - on average - even if cared for properly, still clap out faster than sealed units.
Though convincing, the advantage isn't universal. Much depends on what the bearing is doing. Roller bearings aren't suitable for all purposes, and sealing a poorly made bearing doesn't magically fix other faults. However, when a machine has a limited life, and they all do, it usually pays to fit the cheapest bearings that last longer than the machine. Unless done for free by an enthusiastic amateur and downtime doesn't matter, maintenance is gob-smacking expensive. In a clean location a cheaper unshielded bearing, or Oilite, or even an axle running in cast-iron might be good enough.
As always, there's a balance. Wheel bearings are a good example - they work hard in dirt. Early on, the answer was regular maintenance in hope new grease would force out any muck that had penetrated. Didn't work that well, the old-bangers of my early motoring all needed replacement wheel bearings. Much time and money wasted. Old-fashioned wheel bearings screamed 'room for improvement' and eventually it happened, hurrah. Cars are more reliable now I don't have to crawl underneath with a grease gun every 6 months!
Same problem with production tools; while an employee might not care about downtime, the owner has to keep tools operating. Machines that aren't cutting metal are burning money. Ideally the bearings are maintenance free, and if they do need replacement it can be done quickly. To achieve high reliability, a production lathe is probably fitted with high-specification bearings. Home machines are much less cost critical: my lathe is fitted with distinctly ordinary sealed bearings, still fine after 5 years light use. If they fail, I shall replace them with better, but so far so good!
Bearing life is measured as the number of revolutions before any sign of fatigue can be detected. How many of us us have any idea what our bearings are rated for, or how many revolutions the bearings have already done, or how many revolutions we add per year? Understanding the numbers reveals if the design is good or bad. I feel even mildly neglected inferior bearings should last years in amateur hands without much fuss.
How much time does your lathe spend cutting per week? Not much in my case, I'd guess about an hour per week on average. From this table, at that rate, a rather ordinary bearing will last 150 years. Someone cutting a hour a day, might get 20 years. Note that although the ordinary bearing is OK for the likes of me, it's no good for anyone needing 'Continuous 24 hour operation, reliability important'.
Over specification in engineering is an egregious sin. 'Engineering is the art of doing for 10 shillings what any fool can do for a pound'. Incidently, the quotation has been attributed to George Stevenson, the Duke of Wellington and Neville Shute. I'm sure it predates Neville. Does anyone know for sure - it's not in my Dictionary of Quotations.
5505 forum posts
About 200,000 miles and 26 years on my last Toyota sedan without looking at the wheel bearings before I traded it in. Good quality taper bearings in good grease run "forever".
But Chinese bearings are of a widely varying quality and so is their grease. If you replace with SKF, FAG or Timken and use good quality clean wheel bearing grease you should get your 200,000 miles out of your lathe.
The ArcEuroTrade website has a couple articles on changing bearings on mini lathes that might be applicable to yours as they all seem much of a muchness. (Well to this uninitiated outside observer anyway.)
Edited By Hopper on 11/05/2021 10:54:52
|Ketan Swali||11/05/2021 11:10:10|
|1355 forum posts|
I think you should re-check the TRB number. The last digit 2 means it is a 15mm bore.
Is it possible you meant 30206 which would make it a 30mm bore?
Ketan at ARC
|Bob Stevenson||11/05/2021 18:56:08|
|514 forum posts|
Thanks fro the later crop of responses which are all valuable to me.....
Ketan,......Yes, a slip of the keyboard.....30206 it is!.....I'm impressed with your site and the disassembly photos for mini-lathe.. Excellent resource for users.
Hopper......Thanks for info, encouragement and the tip about ARC site!
S.O.D., (Dave)....Great overview and info on bearings...read it twice so far.....think quote is in second volume of bio on Wellington by Eliz. Longford..can't remember title but first vol. is 'Years of The Sword'...
Niels,......Thanks for advice....I may do this for starters and see how I get on....
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