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Eureka Eureka lubricating

praezis

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Feb 11, 2008
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Hello,

if time allows, I will finish my Eureka overhaul one day...
But I wonder how to lubricate the ball bearings, where to place lubricant, and which oil or grease to use.
Recommandations appreciated,

Frank
 

John Hubby

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Sep 7, 2000
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Frank, it appears from all these I've worked on that some kind of grease was used originally for the bearings. However, those all turned to gum, polymer or the like. Based on excellent results from using it for clock mainsprings (especially 400-Day clocks) I have been using Mobil 1 High Mileage full synthetic oil (10W40) for about 10 years now with excellent results. It's available in quarts which is more than a lifetime supply but you get that for about half the price of a 4 ounce bottle of "clock oil".
 

praezis

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Feb 11, 2008
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Hello John,

thank you very much for sharing your experience.
These bearings are so far from horological bearings, I was at a loss. Wonder why this question does not appear more often.

Frank
 

James McDermaid

Registered User
Apr 29, 2011
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It is my understanding that the ball bearings should be lubed with synthetic super light clock oil which is wiped almost dry so there is only a light film.

Not grease, you want no drag here.Ball bearings can run nearly dry as there is no friction wear.

Jim
 

James McDermaid

Registered User
Apr 29, 2011
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Another thing to think about is how much electric current flows through the bearings. The coil in the balance wheel gets it voltage return to the frame of the clock through the steel balance spring which I would think has more electrical resistance than through the bearings.

There is nothing to stop the inductive kick (reverse EMF) from the magnet coil when the flag contacts open and I would think there could be a little pitting if the energy is not dissipated, like make sure the balance spring is sightly mounted.

Maybe there is no worry at all :)

Jim
 

praezis

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Feb 11, 2008
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There is nothing to stop the inductive kick (reverse EMF) from the magnet coil when the flag contacts open and I would think there could be a little pitting if the energy is not dissipated, like make sure the balance spring is sightly mounted.
Very true! This is another topic, so I started another thread.

Frank
 

Terry Gray

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Apr 15, 2018
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i am told that modern fully synthetic oil is being used such sa 0 50,clock ball bearings bear absolutely no relationship to industrial bearings,the lack friction is the key,do not put grease any where near them,i use a pair of cir-clip pliers to undo locking ring they can be very tight,i find the points fit exactly,remove glass and metal plate note just where the tab goes,make sure you have a container for the bearings they are easy lost,look at the race for scoring and the balls,if the race is scored it's possible to move it to a new position,new balls are readily available,i use 5/16 on mine,i use pivot oil suit for pivots from .2 to 6 mm but i am sure any good light oil will do,i just cleaned mine in soapy water reassembled with out the glass ie balls and metal then dribbled oil on to the bearings be generous with the oil dont skimp but dont flood them so it will leak out later,the oil will coat the bearings by osmosis,i have used this on my Eureka s and they run very well with in a few minuets a week.