My lathe is the same. The strange thing is that if I top up the oil cups and run the lathe in forwards, one bearing immediately sucks up the oil and the other throws it out of the oil cup. If I top up the cups again and run in reverse, the first bearing throws it out and the second sucks it up. Very odd. Anyway, as these are self oiling bushes, they should run for years without needing replenishment. I now do it once every six months or so and don't worry about it.

Andrew M

Ian

The bushes in question on the Super 7 were originally specified as "Oilite". What may have been changed over the lathe's life is another matter

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In my opinion, Norman, your understanding was correct; and the answer to your question is NO.

At the risk of being ridiculed for debating 'How many Angels?' … let's try thinking about this:

• Oilite bushes are engineered to retain oil within the structural interstices, and to release it gradually to the bearing surface.
• Capilliary action is involved in both aspects of this process.
• Between the rotating shaft and the bearing surface, there will be a small but finite gap [if the gap is large, something is already worn, and this analysis may not apply] which fills with oil.
• The shape of that oil-layer will, in reality, not be a 'cylindrical tube' because of side loads on the shaft. [it also differs in orientation, in the two bushes; producing the 'odd' behaviour]
• Rotation of the shaft, combined with surface tension of the oil, acts as a pump and draws fresh oil through the Oilite bush.
• Drilling the bush would change the dynamics; for the worse.

Over to the drillers, for their counter-argument

MichaelG.

In response to a similar enquiry of mine (but in a different application) on this board the weight of opinion then appeared to be:

Fit two oilite bushes of such length that there is a small gap (say 1mm) between them coinciding with the oil-feed hole.

I adopted this suggestion, which superficially to me at least, appears to exploit the characteristics of the oilite bushes and allows easy oil replenishment and 'top-up' without any drilling or machining of the bushes. It appears to work very well for me.

Regards,

Phil

Somewhat dubious as to the value of simply adding an undefined "oil" to Olite bushes. As supplied oil and bush will have been engineered to work well together over the projected life of the bush. Adding a different oil could well affect the flow characteristics within the bush leading to oil starvation making things worse. As with so many things steady development over the years has resulted in modern components having much better performance than older versions when used as per book recommendations. Flip side being that straying outside the book is often a very bad idea. Back in the day being inspector meticulous and careful about how you did things could often win much better performance in your specific applications. Not so much today. Its hard to beat millions of development hours!

Inclined to think that the "soak in oil before fitting a bush that has been on the shelf for a long time" are more about ensuring there is a local oil film on the surface immediately on start up than actually getting oil into the bush proper. Penetration into the bush is probably minimal so the proper oil soon drives out the added oil.

Always felt that a felt wiper between oil hole and a plain bush is much better than simply pouring oil into a hole. Especially Southbend countershaft style where a rectangular felt sits in a groove distributing oil all along the bearing. Steel on cast iron lasts forever so long as the felt is kept wet.

Clive.

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Clive,

I can't argue against that ^^^

But I would mention that Myford offered [as the politicians say] "very clear" advice regarding lubrication of the countershaft bearings, on pages 17-19 of the manual:

• Use ESSO NUTO H32 oil
• Replenish the two oil cups daily
• 'The hardened steel countershaft runs in oil impregnated bronze bearings which are located in the swing head. Oil cups are provided for occasional lubrication.'

MichaelG.

I suspect the daily replenishment of the oil cups is for a machine in regular daily use for a fair spell of use each day, too much oil will do less harm than too little so a bit of mess can soon be wiped off.

Mike

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This is worth a look: **LINK**

http://www.bowman.co.uk/news/a-brief-of-oilite-bearings

MichaelG.

.

Well … there's the two that are currently fitted to Norman's S7

[see the opening post]

But, I suspect that those have been 'improved' by some previous owner.

MichaelG.

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P.S. … I should have said that you make an excellent point 

Edited By Michael Gilligan on 17/07/2018 22:44:11

Oilite bushes have been around in the current form for 90 years. 25% of the bearing is oil space.

Ian S C

If Nottingham Myford drilled it, drill it. Gainsayers should provide compelling technical backup and then still agree with the Manufacturer!