Essential Clock Movement Servicing Steps

Why does a mechanical clock movement require servicing? The answer is quite straightforward. Maintaining your clock’s movement is essential to ensure it continues to function properly and extends its lifespan.

Regular servicing reduces wear and tear, ultimately preserving the clock’s functionality. Ideally, most clocks should undergo servicing every three to five years to maximize longevity.

This article outlines the seven steps I typically follow when servicing an antique or vintage clock movement, using a common American, pendulum-driven movement as an example, Seth Thomas’s Type 86 8-day time and strike movement.

Step 1 – Initial Assessment: Upon receiving a clock, my first task is to determine if it runs. I assess whether it runs and strikes correctly and completes its full 8-day cycle. If it operates for fewer than 8 days, there may be an underlying power problem, which could stem from various factors like weakened mainsprings, worn bushing holes, bent arbours, and so on but more often than not a good cleaning will improve its run time even if there is some wear in the movement.

_{The movement is mounted to the front of the clock}

Step 2 – Addressing non-running clocks: When the clock does not run, I conduct an examination to identify potential issues such as missing or broken components, bent wheel assemblies, and arbours, damaged or worn gear teeth, worn pinions, snapped mainsprings, and broken or broken clicks along with any missing parts like suspension springs or pendulum bobs.

Nevertheless, when all components are intact and the mainsprings appear to be in good condition, I take measures to ensure the clock is properly adjusted for an even beat.

I’ve observed that on many occasions, the mainsprings are wound tightly, and relieving this tension tends to address the problem (albeit temporarily), allowing the clock to operate relatively smoothly. However, if it stops running soon after starting, I note the problem areas and set it aside for servicing.

Step 3 – Disassembly and assessment: After removing the hands, dial face, and taking the movement out of the case (4 screws hold the type 86 in place), I conduct a thorough visual inspection. This step involves checking for damage, dirt, and excess oil, and determining the extent of cleaning required.

I use retaining clamps to safely secure the mainsprings’ power and then proceed with disassembling the movement. Disassembly includes removing outboard parts such as the crutch and suspension rod, releasing the four or five bolts holding the plates in place, and proceeding to remove the wheels and levers.

I assess wear in various areas, including pinions, pivot holes, arbor conditions, and connections between plates and pillars. I also look for tool marks and indications of previous servicing.

Step 4 – Cleaning the parts: Cleaning the clock movement parts is crucial, and I prefer using an ultrasonic cleaner. I use a mild alkaline, biodegradable degreaser concentrate for cleaning. I organize the parts in compartments for easy identification, with strike parts separated from time-side parts.

For open-loop mainsprings such as the type 86, I detach them from the main wheel before cleaning. To guarantee that the mainwheels and springs are reinstalled in their original spots, I mark them with either “T” or “S” for clear identification.

Drying the parts promptly is vital to prevent rust formation. I use shop towels and a portable hair dryer to ensure all areas are dry. Lantern pinions tend to be especially difficult to dry and a hair dryer is an ideal tool to remove excess water.

After cleaning, I inspect the cleaning solution and, if suitable, reuse it.

Step 5 – Polishing pivots: The next step involves polishing the pivots. If the pivots are in good condition, a few passes with an emery board are sufficient. A small metal lathe is ideal but a portable drill will do.

For pitted pivots, more aggressive cleaning and polishing may be necessary, and in extreme cases, pivot replacement may be required. Cleaning and wiping the pivots with a soft cloth is essential, followed by bushing if needed.

Step 6 – Bushing, broaching, and pegging pivot holes: I determine which pivot holes need bushing by assessing lateral pivot movement and marking each one (with a black marker) to be bushed.

I use a Bergeon bushing machine known for its precise work. After making the bush hole, I clean it from chips and burrs, followed by broaching if necessary. In the process, both cutting and smoothing broaches are used to ensure an optimum fit.

Drilling a hole with Bergeon bushing machine — _{A hole is enlarged with a} _{cutter to accommodate a new bushing}

All pivot holes are pegged with toothpicks until no residue remains.

Step 7 – Making necessary repairs: Other potential repairs include re-pivoting, straightening or replacing wheel teeth, sourcing parts, making new parts, and addressing issues with worn lantern pinions and escapement components.

Step 8 – Reassembly, testing, and adjustment: Finally, I reassemble the clock movement, carefully securing the gears and levers in place. I use a pivot locator to move the pivots to their correct location. Once reassembled, the movement goes through a testing process and adjustment on a test stand, ensuring it is in beat and properly regulated. This testing phase can take up to a month before returning the movement to its case.

_{A movement on a test stand. Attached is a microphone for a beat amplifier}

In conclusion, servicing antique or vintage clocks significantly extends their lifespan. These seven steps provide a general guideline for clock movement servicing, though some steps may require further explanation, and individual procedures may vary among clockmakers.

September 29, 2023

From chaos to order – reorganizing my clock office

My wife calls it the clock office. It is, after all where I work on my clocks and where some are on display. It is also where I compose articles for this blog.

However, it has been getting very cluttered, and I am tired of how disorganized it looks.

We have 4 bedrooms in our 2-story home and my office is in the smallest one. It is also the one I prefer because of the afternoon sun and it is probably the brightest room in the house with two large windows facing west.

In 2018 the office was manageable but as anyone who collects things or has a hobby, space runs out very quickly.

By December 2022 the office was getting very crowded and it was at that point that I decided a major change was necessary. I was also getting tired of looking for places to put things and losing things amid piles of stuff.

The small desk and hutch had to go. It is a real junk collector but more importantly, the hutch area limits the size of computer monitors I can use and I always work with two monitors. The computer desk and hutch will now go to the curb. The computer desk will remain in the same location, however. A new computer desk with a more open design and a back upper shelf for the monitors is replacing it.

_{Corner bookcase} _{with spring winder and Bergeon bushing machine}

I have been making small changes in the last 4 years but this will be the biggest redo ever. In 2018 I built a shelf for my ogee clocks putting them up on display where they belonged instead of on the floor.

_{From the left are clocks made by Waterbury, George Clark, and two Chauncey Jeromes}

In early January 2023, I added a shelf on the south wall for my Canadian Clocks, the same width, and height.

_{From the left are clocks made by the Hamilton Clock Co, an Arthur Pequegnat Canuk, two Arthur Pequegant Maple Leafs, and a steeple clock made by the Hamilton Clock Co.}

The new computer desk may look smaller but it is in fact one foot wider and made with tubular steel and the finest Chinese pressed wood and veneer that money can buy. It also allows for the scanner (not yet placed in the photo) to be located on a lower shelf. The wires in the back are a bit of an eyesore at the moment but a little cable management will fix it.

The bookcase has been moved to a closet that has had the door removed. With the bookcase out of the way, it frees up space for the lathe.

The basement has a work area where clock case repairs, restoration, painting, veneer work, and so on are done. A year ago I moved my Taig metal lathe to the basement but with the reorganization of my office bringing it back up will eliminate frequent trips up and down stairs.

So, that’s it for now. It’s not finished yet, call it a work in progress. When everything is where I want it to be and I am happy with the reconfiguration I will update with a few photos.

January 17, 2023

Forestville mantel clock servicing – not fun when things go wrong! Part II

Back in October (2020), I wrote about the challenges of working on this mantel clock by Forestville.

Recap so far

It is a nondescript Art Deco-style German mantel clock made in the 1960s sold under the Forestville name, a Toronto-based company that assembled clocks up to the 1970s.

The rack and snail movement is relatively simple to work on with all the adjustments, save for the stop wheel, on the outside of the plates. The mainspring barrels can be removed separately for servicing, typical of movements of the period.

The hairspring escapement is something I did not attempt to clean. They can be finicky to work on and if the movement has been running beforehand, like this one, there is no pressing need to mess with it. Three screws detach it from the movement.

The bane of clockmakers – the broken pivot

When working with German and French movements particularly one must always be very careful of the small pivots. Normally when I work on this type of clock I am very aware of how easy it is to bend or break the tiny pivots and this clock was no exception. After taking apart the movement and reinstalling the gears to determine bushing wear I noticed the front plate center wheel pivot had come off.

Thinking I was careful guiding each pivot in place with a pivot locator I either applied too much pressure closing the plates or it was hanging on like a tread. Regardless, it broke. Compared to a pair of tweezers it is very small.

Broken pivot compared to a pair of tweezers

My experience with pivot repair is limited. I don’t come across broken pivots very often. Compared to an American clock that has much larger pivots these are tiny, perhaps 0.5mm or so. Although I have bushings that fit I do not have pivot wire that size and had to make do with a piece from my assortment of 0.85mm to 1.10mm wire. Not pretty but functional.

First, using a centring bit followed by a high-speed bit on my Taig metal lathe, I drilled 5mm into the shaft, enough to securely anchor the pivot wire. Once the wire was inserted, I applied high-strength Permatex Threadlocker Red to secure the wire in place.

A centring bit is essential when drilling a starting hole in an arbour.

After the 24 hour curing period for the adhesive, I installed a bushing in the front plate and put the gears back together to check the action of the new pivot. It is working okay. I will reserve judgment on the repair until the other bushings are installed.

There is more wear on the time side that at least 3 new bushings are required, two on the front plate and one on the back.

Out of an abundance of caution, I installed an additional 2 bushings. In total are T2, T3, T4, rear plate, and T4, T5, front plate. All bushings are on the time side which tells me that the strike side did not see much action, typical for many mechanical clocks since some folks find the noise of the strike bothersome.

2 new bushings on the front plate, new pivot in the centre of the photo (untrimmed)

3 new bushings on the rear plate using a Bergeon Bushing Machine

Servicing the mainspring barrels was more frustrating than I anticipated. Both mainsprings refused to catch on their hooks when I attempted to install them back into their barrels. The mainspring opening must be precisely on center to catch. Lesson learned; after a few tries, I successfully got them hooked back into the barrels.

Re-assembly

The new pivot was trimmed to fit and given a final polish prior to installation. Now to put it all together and see if the work has paid off.

I was especially careful putting everything back together and very mindful of how easy it is to snap off one of the delicate pivots. All went well. On the test stand, I ran the strike side through its sequence; it is going into warning and striking on the half-hour as it should. Now for the time side.

Repairing a broken pivot. Left on the lathe overnight to cure the adhesive and keep the pivot straight.

At first, the escape wheel would stop after a minute or so but after oiling the pivots including those on the hairspring (minus the jewelled ones, of course) it runs well.

Testing the Forestville movement on a non-standard stand

I will continue with the test of the movement but so far, after two 8-day running cycles, things are looking very good. The next step is to re-install the strike hammers and other moving parts and return the movement to its case.

November 19, 2020

So you want to fix a mechanical clock – Part II – advanced tools

tools are essential for clock repair because they enable precision and accuracy, which are critical when working with delicate mechanisms and intricate components. Let’s identify the key reasons.

Antique and vintage clocks can lose significant value if repaired improperly. Using the right tools minimizes the risk of damage, preserving their historical and monetary worth. The right allows you to handle small parts without causing damage. Specialized tools ensure components are handled carefully and correctly.

Proper tools make the repair process faster and more straightforward. Having the right tools helps build confidence and competence. They allow you to focus on understanding clock mechanisms without being hindered by improper equipment.

This article will describe some of the more advanced tools required to tackle the repair and/or cleaning of mechanical clocks.

Based on years of clock repair experience, I recommend the following tools for those ready to advance their skills in clock restoration and repair. Most specialty items will need to be ordered from clock supply companies such as Timesavers (USA), Perrin (Canada), or Meadows and Passmore (UK). Other items such as an ultrasonic cleaner can be ordered through online merchants.

Part I of this two-part series describes the basic tools for those just starting out. The tools/equipment described here are for the more advanced hobbyist/amateur horologist.

A Suggested List of Items

Ultrasonic Cleaner: This Harbor Freight special will do for now but it is so low-powered that a newer, more powerful machine is on the horizon. It does not perform as well as better quality machines and it has a limited load capacity. An eight-minute limit for each cycle means that several cycles are required to properly clean clock parts. It is a start.

Spring winder: An essential tool. Disassembling clock movement also includes servicing the mainsprings. Mainsprings must be inspected for breaks, cracks and splits, cleaned of old oil and rust (as long as there is not too much rust) and lubricated prior to re-installing them into the movement. Too much rust and they should be discarded. I generally do not replace springs in a movement unless they are quite set, or have breaks or cracks. I have found that the steel in the original movement is better quality than can be found today. Mounting the spring winder on a piece of hardwood provides a stable tool and allows it to be clamped to a work-desk.

Although there are other types of spring winders, the Olie Baker winder is one of the better choices in my view. It is well made and should last for years. If you can find a used one you will save a little.

Joe Collins has plans for a homemade spring winder that you can find on the National Association of Watch and Clock Collectors site.

_{Mainspring servicing; taking the clamp off to inspect and service the mainspring}

_{Mainspring barrels require collars supplied with the Olie Baker spring winder}

Bergeon 6200 Bushing Machine: Some bush by hand and they are to be applauded for their patience and skill. I chose a bushing machine for the delicate work of installing bushings. This is the Bergeon 6200 which is made in Switzerland. It is exceptionally well made and relatively simple to use.

The machine can be bought separately or with a set of cutters and other hardware (above). The cutters can last 15 years or more. Of course, you must also have an assortment of correctly sized brass bushings that are purchased separately from any clock supply house.

To operate, a correct size cutter is placed in the bottom end of the steel shaft, holes are cut after which the new bushings are punched in place with a hammer head fitted to the shaft.

Punching the bushing home — _{Pressing a brass bushing into the drilled pivot hole}

Six bushings on back plate — _{Six new bushings on the back plate of a mantel clock}

Lathe: Good quality mini lathe are available from Sherline, Taig and others. A cost effective option is the Taig Miniature Lathe for metal. The Taig lathe was originally designed for precision machining of watch and clock parts; ideal for clock repair applications. The small office space in my home means that its compactness, portability and relative simplicity are attractive features.

Reference/Reading material: I recommend the Steven Conover series of repair manuals. The manuals are well-written, and detailed and are great resources for the beginner or the advanced amateur.

Steven G. Conover; Clock Repair Basics
Steven G. Conover; Striking Clock Repair Guide
Steven G. Conover; Chime Clock Repair

The acquisition of clock supplies and equipment has been a personal journey for me. I started with a few basic tools for disassembling movements, gradually learning what additional tools were necessary and steadily expanding my collection over time.

Several years ago, my first major purchase was the Olie Baker spring winder. A few months later, I added a Bergeon bushing machine, complete with cutters and a supply of bushings. Most recently, I acquired a Taig mini lathe with accessories. This mini lathe will enable me to advance my clock repair skills by allowing me to polish and burnish pivots properly, replace worn or damaged pivots, and perform other specialized repairs. As new challenges arise, I plan to seek out additional specialized tools and equipment to further enhance my capabilities.

And finally

Set a specific goal, research your requirements, and build your collection of tools and equipment gradually while sticking to a reasonable budget. Clock repair can be more affordable than you might expect, especially when costs are spread out over time and some tools can be sourced from the used market.

I hope you found this helpful! If there’s a tool or piece of equipment you consider absolutely indispensable, I’d love to hear about it.

November 18, 2017

Rate this:

Share this:

Rate this:

Share this:

Rate this:

Share this:

A Suggested List of Items

Rate this:

Share this: