Oiling the escapement

Following the discussion in another thread I decided to conduct a little experiment:

First I stripped down my skeleton clock (John Parslow design in ME) and gave it a thorough clean. I re-assembled it using M&P clock oil for the pivots but leaving the escape wheel and pallets dry. I fully wound it and ran it for a week without regulating it and it lost 2 minutes in the week.

I then rewound it and added a tiny drop of M&P clock oil to the tip of a couple of the escape wheel teeth as recommended in the BHI publication "The Practical Lubrication of Clocks and Watches". I expected it to run slightly faster but a week later it had again lost 2 minutes.

Any thoughts?

Russell.

I like the fact you decided to experiment to see if this made a difference, well done.

I'll take a punt that atleast in the short term the oil wont have a noticable effect on the time lost. It may be that the time lost isn't dictated by the lubrication but to more subtle allowances in the part itself.

Michael W

Thanks for your input Michael.

The purpose of my test was to see what the effect of adding oil to the sliding surfaces of the escapement was on the timekeeping. It is often stated that the clock will speed up if oil is added (friction reduced) even though the wider pendulum swing would slow it down. The actual time lost is irrelevant as I had stated that I hadn't regulated the clock.

Russell.

Is there any possibility of dust Russell?

It is my understanding from reading. I am not a clock maker that escapements can be left dry, this avoids dust getting mixed with the oil. there is also no viscous drag running dry. The loads are so small that the parts polish themselves rather than wear apparently?

Regards
John

Edited By John McNamara on 18/05/2016 07:48:52

Edited By John McNamara on 18/05/2016 07:50:03

Escapement were always oiled on the clocks built by my father who spent most of his life as a working clockmaker, Skeleton clocks always went under a glass dome so dust was not really a problem. A rate of 2 minutes a week is very good I used marine chronometer when I was at sea and a good one was about 20 seconds a day but they did everyday.

Hi All

I Found the following search useful.

**LINK**

Gee several oils per movement !

Regards
John

Russell,

I think your demonstration supports our assumption [discussed in the other thread]

i.e. that what Harrison saw was the effect of viscous drag [from stale, gummy, neatsfoot oil] being alleviated by the application of fresh oil.

Your test, although very worthy, covers a different set of conditions ... You have compared a clean, dry, escapement with a clean, freshly-oiled escapement ... The effect of adding the oil may well be 'numerically trivial' in the course of a one week test.

I have no doubt that Harrison observed the effect that he describes in CSM, but I think his point is that other designs were more sensitive [to stale oil] than his. Our modern oils are so much better, that we are unlikely to be 'starting from there'.

Thanks for taking the trouble to do the experiment, and report the results.

MichaelG.

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Edit: corrected a couple of typo's.

Edited By Michael Gilligan on 18/05/2016 08:50:32

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John,

This is a useful overview: **LINK**

MichaelG.

Yes, it's under glass. 2 minutes a week isn't particularly good. When it is properly regulated it gives about ±½ minute a week. Of course a clock in a benign environment on land doesn't have to cope with the condition at sea!

Russell.

Agreed Michael. The application of oil to a dry escapement will reduce the friction losses and I expected it to affect the timing but the effect was too small to measure, particularly with no second hand on the clock. I should perhaps test it over a longer time but then other effects might dominate.

Anyway, it's good news for John who is planning to build an oil free clock.

Russell.