Tip & How-To about Watches

Clock Bushing Replacement

BUSHING TIPS



-One of the most common stoppage problem is caused by increased friction and mostly due to lack of incorrect amount of or lack of oil. If discovered in time, the movement can be cleaned and oiled with only high quality Clock oil, then it will be good for another 5 years or so. Insufficient lubricants eventually cause wear in the pivot holes and/or bushings.
-After a pivot is worn it will change the depth of the wheels and pinions to such an extent that the power train will stop due to improper gear meshing. Wear causes a pivot hole to become egg shaped.

HOW TO TEST

-One testis to completely let off the power from the power train and rock the main wheel back and forth. Then you will clearly see the pivots that have the problem jumping back and forth.


Sample one:

Sample two:
Examples of EGG Shaped pivots above.

WHEN DO YOU NEED BUSHING REPLACEMENT?

-One rule of thumb used by many repair persons, if a bushing is worn one third or more the diameter of the pivot it needs to be replaced.
-Above is Two example of a worn pivot's [note the black gum med up oil around the pivot in photo above]. This is a dead give away of a potential problem.

centerline PIVOT

-Before disassembly, mark all bushings that need replacement in the correct geometrical direction of centerline.
-Complete disassembly of movement is required.
-Then you will need to file out the exact opposite direction with a small file, this will ensure that when you start drilling out the hole it will be centerline.
-Set-up the drill press and lock the plate on to the drill press making sure you find the centerline of the original pivot hole. Use a steel short stock the same diameter of the old pivot and chuck it in the drill press after the plate is secure, select the proper bushing that you intend to press in.












PRESSING IN THE BUSHING
-With a small broach taper slightly the inter plate before the insertion of the bushing. Do this from the inside of the plate, this will ensure that the bushing will never fall out.


-Select a bushing that is a bit undersized after it is pressed into place, then open the hole up to the correct diameter.
-Use the drill press to push in the new bushing from the inside plate out.
-Be sure to broach out the pivot bushing in both directions, this will leave the hole in an hour glass shape ”===)I(===” and will reduce friction.

COUNTER SINKING.

- Counter Sinking is very important and not only needed to hold the oil in place but also to reduce the amount of actual friction on the pivot. [Note:] don't get carried away the first gears tend to have a lot of torque on them and a lot of bushing surface is needed; however, the final pivots do not and are very sensitive to friction.
-Barrel Bushings, these are often overlooked. This is an example of a bushing before and after replacement.

Hope this tip helps.

R/
David

http://antiqueclock.clockstop.com/bushing.htm

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I have wound muy omega speedmaster automatic to tightly at the bezel and it has stopped working. Can you tell me if there is something inside that can be released tostart it again?


There's a misconception that mechanical watches can be "overwound." Mainsprings in old watches can indeed set in place and freeze up if they are wound tightly and not permitted to unwind, but the steel used in modern mainsprings used in the past 50 years or so is an alloy that's much less likely to bind up compared to 19th century pocket watches. In addition, the winding mechanism in an automatic (aka, self-winding) watch is designed to slip once the spring has been fully wound so that the rotor and winding parts aren't damaged by suddenly binding up. In a manual wind watch, once the mainspring is fully wound, it's simply not possible to wind the watch further unless the mainspring snaps or comes loose from its anchoring--in which case, you'd be able to wind the watch forever without ever storing power in the mainspring to drive the movement. While it is possible for a watchmaker to open your watch and release tension on the mainspring, it's overwhelmingly likely that something entirely different is keeping your watch from ticking and keeping time.

Mechanical watches generally stop running for two reasons: (1) lack of power to the movement; or (2) something in the movement that is preventing the movement from running. If your mainspring is fully wound, you have power to drive the movement. It's time to think about what could be causing #2.

Problems in the movement are usually caused by dust or dirt that preventing a delicate movement part from working properly (e.g., dirt at the pivots can freeze up a gear, stopping a movement). However, it's also possible to have a mechanical failure, such as a bent tooth on a gear in the train. A further possibility is so-called "overbanking," which some believe is the origin of the myth of overwinding. A mechanical watch's balance assembly drives a tiny little forked lever back and forth to control the escapement and the rate at which the watch keeps time. If the watch receives a physical shock or if the parts are worn, it's possible for this tiny lever to get bumped out of its tiny pivot and jammed in place. When that happens, the watch will stop, even though a superficial check will seem to indicate that the balance is still moving freely. At the same time, because the watch isn't ticking, the mainspring isn't unwinding, and so the watch cannot be wound further.

In my experience, watches usually stop running due to dirt at the pivots or on one or more gear teeth. I generally see overbanking in older watches or mechanical watches that have been less precisely made and not routinely cleaned over their working lives--though I have seen it also occur in a few newer watches that were dropped. Better designed watches--and I would include Omega in this category--have escapement levers with built-in guards to make it more difficult for them to overbank.

As for how dirt gets into a watch that's supposed to be water-resistant and generally sealed against exactly that problem--well, as odd as it sounds, watches "breathe," and this process draws in dust and dirt over time. Worn against the body, a watch warms up and expands the air inside it, pushing some of it out of the case; upon cooling, some air is drawn back into the case. This process is obviously reduced in watches designed with a significant degree of water resistance (aka 50 meters or more), but the process is accelerated when you pull the stem out to set the time or even wind the watch via the stem--there's some degree of air gap between the stem and the stem tube, or else it wouldn't be possible to turn the stem. This microscopic dust--in minute quantities--mixes with the lubricating oils inside a mechanical watch and increase the friction in some of the key pivots. Over time, the combination of naturally solidifying oils that are thickening and a minute amount of dust can turn lubricating oil into glue. The watch cleaning process flushes the old oil and accumulated dirt from the pivot bushings so that fresh, uncontaminated oil can be used to re-lubricate these key gear axles.

Bottom line: if your mechanical watch has stopped working, it's much more likely that something is interrupting the intricate gears in the watch movement rather than a problem with the mainspring. A competent watchmaker or watch repair technician should be able to identify the problem relatively quickly and give you a definitive answer as to the true cause of--and cost to fix--your watch.

Jun 11, 2011 | Watches

1 Answer

pendulum in beat but stops running after a few


CLOCK OILING TIPS * NOTE: Many Master Clock Smiths and Hobbyists used many different oils and as many different techniques.
* It is only good sense to use only the best in quality when selecting clock oils and grease. A number of fine oils are made especially for clocks. The oil used should stay in place and not evaporate easily and have no tendency to gum or get sticky as it ages. Most clock oils meet these standards. [CAUTION: Never consider using non-clock lubricants, as they tend to not really work well in clocks. Some are too light and cause unnecessary bushings wear, while others are too thick or can evaporate, over time will gum up and stop the clock prematurely.]

Oiling Procedures
-Main-springs are oiled after cleaning and before they are recoiled.
-Teeth and pinions are never oiled.
-Normally, the dial train of gears, hour wheel, minute wheel and minute wheel post are not oiled. However, oil is used between the center shaft and cannon pinion where slip friction is present in setting the hands.
-All points of friction such as train wheel pivots to bushings are oiled. Verge faces are oiled directly.
-Oil is always used sparingly and should never run all over the plates.

Hope this tip helps.

R/
DAvid

http://antiqueclock.clockstop.com/oil.htm

Feb 08, 2010 | Watches

1 Answer

omega automatic seamaster losing time


Most likely your watch needs to be serviced.

Every watch, both mechanical and quartz needs regular service.

When the oils in the watch dry out they get gummy and will work against the gear train. They also stop lubricating and friction builds up causing wear.

Hope this helps,
Ken
Yellowstone Watch Inc

Oct 04, 2009 | Omega Seamaster 2561.80 Wrist Watch

2 Answers

watch doesnt work even with a new battery


The 2 most common reasons for a watch to not work after a battery change are:
1) The circuit is not functioning properly.  99% of the time it is not efficient to have this fixed.  It almost always needs to be replaced when this is the problem.
2) The oils in the watch have either become thick like car oil, or thin and now the metal parts are causing too much friction.
The 2nd problem can be fixed by having the watch serviced.  Servicing is usually between $50 and $100 for Fossil's depending on where you go.  This may not be efficient since most Fossil's are less than $150.
Stores that service watches are Tourneau and Precision Time: www.tourneau.com www.precisiontimeco.com

Jan 09, 2009 | Fossil CH2331 Wrist Watch

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