I have never been completely happy with how the movement runs in this Junghans Crispi wall clock. When I got the clock in 2017, I jumped right into restoring the case because it was an interesting challenge to put the clock together from a bunch of parts.
Junghans wall clock, circa 1899, model – Crispi
Now, eight years later, the clock continues to disappoint. The case remains in great shape, but the movement has been a consistent letdown.
Movement as found, about as dirty as it gets
Let’s take a step back in time.
Winter2017
After completing the work on the case, I turned my attention to the movement. During the disassembly and reassembly process, I accidentally broke not only the strike paddle but also a retention spring. In 2017, my skills weren’t advanced enough to repair the paddle and retaining spring myself, so I had the movement professionally serviced.
Broken strike paddle
During its 2017 service, the paddle was repaired and a new spring was installed. In addition, the movement had received extensive bushing work: six bushings on the front plate and six on the rear.
Three months later, I picked up the clock and hung it on my dining room wall. It ran perfectly for over two and a half years.
Spring2020
For some undetermined reason, the strike became erratic—it would strike incorrectly, fail to strike at all or strike incessantly until the mainspring ran down.
I had a number of other clock projects on the go so I kept the time side going and left it on the wall until later that year.
December 2020
In December, I disassembled the movement and discovered a slightly bent arbor on the strike side cam wheel. All other pivots were straight, and there were no noticeably worn pivot holes—everything else appeared to be in good condition.
I did notice a small amount of dirty oil around many of the pivots. While I was initially a bit surprised, it’s not entirely unusual after more than two years of regular operation.
Unfortunately, disaster struck again. While manipulating the plates, I snapped the paddle arbor retention spring—again! This time, however, I was able to repair it myself.
There was just enough of the original spring left to reuse. The wire is very thin (0.5 mm), extremely brittle, and breaks easily under even light pressure. Using a micro drill with a 0.5 mm HSS bit, I carefully enlarged the existing hole in the plate, reinstalled the spring, and secured it with Threadlocker Red to bond it firmly in place.
The movement was reassembled and tested. After the testing period the movement was returned to its case and ran well until about 6 months ago.
Fall 2024
While the time side was running well, the erratic striking returned, and after a few weeks, the clock began stopping just before the warning phase. I wound both the time and strike sides again to replicate the problem, and each time it stopped at the warning point. Feeling frustrated, I left the clock on the wall, wound only the time side, and still it stopped. Since I had other projects to tend to, I decided to leave this one on the back burner for a while.
The movement on a test stand
Spring 2025
Since I was free of immediate projects, I removed the movement from its case and placed it on the test stand. As expected, the time side ran fine. It was serviced not so long ago. For the last couple of months, however, it has been striking erratically or not at all. It enters warning without issue, but seems to almost stall during the striking process. I want to address this issue, but I also want to disassemble the movement to clean up both the pivots and the bushing holes, as the oil is dirtier than I expected.
Judging from similar movements I’ve worked on, I believe there are three issues at play:
A power issue, which suggests the mainspring is weak.
One or more bent pivots, preventing the wheels from turning freely.
The paddle is not correctly positioned in relation to the star wheel. The hammer begins lifting immediately at the drop-off, which stalls the strike train. Once it gets going again, the hammer lifts easily and quickly. I’ll try repositioning the star wheel to allow more run time before the hammer paddle is engaged.
The first issue means replacing the strike-side mainspring. The second issue involves manipulating pivots. There is always a risk of breaking a pivot when attempting to straighten it, not a pleasant experience, as re-pivoting is necessary.
Check back later for an update on what I discovered—which of the three issues turned out to be the culprit, and whether I was finally able to fix a clock that, at times, seems determined not to be fixed.
As a clock repairer, there are several compelling reasons to keep the original mainsprings if they are still in good condition.
Keeping the original mainsprings ensures that the clock remains as close to its original condition as possible. Collectors and enthusiasts often value clocks with original parts, as they maintain the authenticity and historical significance of the clock.
Older brass mainsprings are not replaceable
Many older mainsprings were made with higher-quality steel and manufacturing techniques and modern replacements may not be of the same quality. Original springs, if well-preserved, may outperform modern equivalents in terms of durability and performance.
Consider the original design of the movement and how it is powered. The original mainspring is designed specifically for the clock’s movement, ensuring the proper balance of power delivery and running time. Replacements, even when sized correctly, may not deliver power consistently due to slight variations in material and design.
Modern mainsprings can sometimes deliver too much power, especially in delicate or vintage movements, leading to accelerated wear or damage to gears and pivots. Original springs are often “seasoned,” meaning they’ve been conditioned by years of use and may be gentler on the movement. Even replacements that have the same dimensions as the original are overpowered. Recommended replacement springs might overload the movement and lead to wear issues sooner rather than later.
Laurie Penman, who authors a regular feature in Clocks Magazine, stresses the importance of considering replacement springs in the September 2024 issue, stating “it bears repeating that if you fit a spring that approximates to the original nineteenth century the movement will be overloaded”.1
Cleaning an open mainspring
If the original mainspring is functional, reusing it can save the cost of purchasing a replacement. In fact, finding an exact replacement for some older or rare clocks can be very challenging for the repairer.
That said, we certainly do not need to send more items to landfill sites. Reusing parts when possible reduces waste and the environmental impact of manufacturing new components.
Inspect the mainsprings during every servicing
Part of servicing a clock movement includes inspecting and cleaning the mainsprings. While open mainsprings are easier to inspect and work with, some repairers may be tempted to skip cleaning those encased in barrels. It’s important to learn how to open mainspring barrels for proper maintenance.
Mainspring barrel
Over time, the mainspring(s) can accumulate old oil, dirt, rust, and debris, which can impede its smooth operation. Removing the mainspring from the barrel or open springs from a movement allows for proper cleaning and lubrication, ensuring the clock runs efficiently.
Open mainsprings that have been serviced
Removing the spring also allows you to apply fresh mainspring oil evenly along the entire length of the spring. But that is not the only reason.
When Should You Replace the Mainsprings?
Removing the mainspring allows you to thoroughly inspect it for any signs of wear, fatigue, or damage that might require replacement. If the spring is in good condition but the hook end is cracked, it can be reused by cutting the spring and fashioning a new hook end. This will make the spring slightly shorter.
However, after a thorough cleaning, the movement will run more efficiently and require less power to run through its designed cycle, be it a day or a week, two weeks, and so, there may be little to no effect from a shortened mainspring. That said, the task of repairing a mainspring is best suited for an experienced clockmaker.
The most straightforward solution for the novice is simply to replace the spring.
Although they may appear set to some, this spring is perfectly usable
As a clock repairer, I rarely replace a mainspring. Even if a mainspring appears “set,” it often still has functionality. The important step is to return the spring to the movement and test it to ensure it meets the required standard by completing its designed cycle. If there is a significant loss, a running time of 2-3 days for an 8-day clock, and if there are no other obvious issues the mainspring must be replaced.
For some, ensuring a clock runs while preserving its original parts might take priority, even if the original mainspring cannot power the clock through its designed cycle. It is therefore essential to balance preservation with functionality.
Using a spring winder while working on a spring within a barrel
By carefully evaluating the mainspring’s condition and the specific needs of the movement, you can make an informed decision that respects both the clock’s history and its mechanical performance.
I am currently working on a mantel clock from the Hamburg American Clock Company. This is Part II in a two-part series. For Part I go here.
The Hamburg American Clock Company is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU and in many parts of the world, it is simply known as HAC.
HAC mantel clock circa 1926
In Part I, I described the steps taken so far which are disassembly, inspection, cleaning of the parts, and polishing of all pivots. The next steps are bushing work, reassembly, oiling (the mainsprings were oiled in a previous step), and finally, testing.
I believe this is the No. 36 movement by HAC.
HAC clock movement #36
The wheels that spin the fastest typically show the most bushing wear, but wear can also appear in other areas, such as the main wheels, which endure significant torque. For instance, I observed punch marks on the cap side of each mainspring barrel. While punching around any bushing hole is generally poor practice, it appears this was done at some point in the clock’s history and can’t be reversed. Nonetheless, the repair seems to have held up well.
Bushing Work
I have seen similar movements with much more wear than this one, but I felt that some bushing work was necessary to extend the clock’s lifespan.
Bergeon Bushing Machine
Six Bergeon brass bushings were installed in total. For the time side (T), bushings were placed at T1 (front and back) and T3 (back). For the strike side (S), bushings were installed at S3 (back), S2 (front), and S4 (front). The numbers indicate the wheel location in the train beginning from the bottom. A couple of pivot holes were borderline, but I decided to leave them as they are.
Reassembly
It pays to be patient and methodical during reassembly. Rushing can lead to mistakes, such as missing steps or improperly aligning parts, which could cause malfunctions or even damage later. Taking the time to carefully double-check the placement of parts, and ensure everything is in its correct place will help ensure the reassembly is smooth and successful.
An older HAC movement, without the barrel cutouts
Once the wheels are in place the lever and there is only one multi-arm ever that resides between the plates. Position it such that the long arm rests in one of the deep slots of the count wheel while a short arm is placed in the cut out of the cam wheel (as above).
Positioning the pivots is a delicate process, and any forceful handling can result in a bent or broken pivot. In this, as in all cases when aligning pivots, a pivot locator is your best tool.
Pivot locator
My usual practice is to position all the wheels and the lever(s) on the plate with the movement posts, first. Once the wheels are correctly located, I lower the front plate onto the back plate. I secure two nuts to the mainspring end which prevents the movement plates from coming apart as I position the upper wheels in the train.
The pin-wheel, which is uppermost and one wheel removed from the fly on the strike side, is placed in approximately the 12 o’clock position, the warning position. At the same time the hammer paddle is positioned between two of the points on the star wheel. More than once I have had to go back in to make minor adjustments when the paddle hangs up on one of the star points. It looks like this one is also a candidate for that very adjustment.
A Timetrax machine is used to adjust the beat and the rate of the movement.
The movement has been placed on a test stand and the time side Is in beat and running as it should according to my Timetrax machine. Curiously, the Timetrax manual lists only one HAU/HAC movement, a three-train one but this one is likely similar to Junghans bracket clock movements which runs at 164 bpm. Junghans is mentioned for comparison because, by 1930, the company had successfully taken full control of HAC.
Testing
The testing phase is crucial in the process of servicing a clock, often taking the most time because it ensures that the clock is functioning properly before it is reunited with its case.
During this phase, the clock is put through various operational checks to simulate real-time performance, which helps in identifying any issues that may not have been apparent during the initial servicing or cleaning process. Issues such over-tightened or loose components can present themselves as well as problems with the escapement mechanism.
The testing phase serves as an important diagnostic step to identify what further repairs or adjustments may be needed.
This concludes the servicing of an 8-day HAU/HAC movement. If you have any comments or feedback on any of the steps in the process, please feel free to share!
Among clock collectors and admirers, the Hamburg American Clock Company is a well-known German company. It is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU and in many parts of the world, it is simply known as HAC.
Time and strike mantel clock, shown without the crownand as purchased
About the Company
The company was formed in Germany in 1873 by Paul Landenberger and Phillipp Lang. Originally called Landenberger and Lang, it became the Hamburg Amerikanische Uhrenfabrik in 1891. The company was very active from 1885 onward, became a cooperative in the mid-1920s, and eventually merged with Junghans, one of the world’s largest clock companies, in 1930.
Original investors insisted that “American” be in the company name but “American” also refers to the manufacturing system adopted from America. The name of the company adds confusion to the novice repair person who might assume that what they are working on is an American-made clock.
HAU adopted the cross arrows as their trademark in 1892, and it became synonymous with the brand.
HAC trademark
In 1925, a few years before its merger with Junghans, the company had a workforce of 2,200 individuals. Junghans remains a successful and thriving company today, specializing in high-end watches.
Condition of Case and Remarks
The case is in very good condition but was missing the crown when I purchased the clock in 2021. Since then, I have sourced a crown, and based on the research I have conducted online, it appears to be the correct “topper” for this clock.
A crown was sourcedand it definitely improves the look
The dial face is in good condition and shows some wear but not like the heavily worn dials I have seen on similar HAC clocks.
A commemorative brass plaque at the base reads: “The Rev. J. H. Cox Chyndale Wes’ Church Aug. 1926.” I assume this church is in the UK, but my online search yielded no information about this person. However, this inscription helps date the clock to no later than 1926. It is possible the clock may have been on a retailer’s shelf for several months or even up to a year or more before that date.
The Movement | Notes and First Steps in Servicing
In typical HAC fashion, the movement is robust and compact and it is a countwheel strike. The spring barrels are capped in the usual manner but feature four holes that make the mainspring visible. Earlier HAC movements had fully enclosed barrels—perhaps a cost-saving measure to use less brass! Otherwise, everything else is standard HAC.
Four nuts hold the movement plates. Once separated I removed the parts and divided the time and strike wheels.
Take careful note of two wires protruding from the rear plate. They act as tension springs, one for the strike hammer and on the opposite side of the movement, another for the lifting lever. These can easily break off, so handle the movement with care.
After disassembling the movement, it was cleaned in an ultrasonic cleaner. My aim wasn’t to achieve the shiniest brass possible but to ensure the brass and steel parts were thoroughly cleaned. There was some rust on two movement posts, which I removed using emery cloth. All parts were thoroughly dried.
The process may vary, but I moved on to polishing the pivots next. Since pivots are quite delicate, especially the fly, it’s important to handle them with care. Avoid applying excessive pressure on the pivot when using a metal lathe for polishing.
Polishing a pivot with an emery board
I know some repairers prefer to avoid servicing mainsprings due to the difficulty of extracting them. However, it is essential to do so for several reasons. Clean and lubricated mainsprings ensure consistent power, enhancing the clock’s accuracy and performance. Additionally, it provides an opportunity to inspect for defects, cracks, and rust and replace them if necessary.
Once cleaned and lubricated, the springs are returned to their barrels using a spring winder such as the one made by Olie Baker.
Spring barrel in Olie Baker spring winder, with an appropriately sized collar ready to be inserted in the barrel to extract the spring
Since brass is softer than steel pivots one should expect some wear on the bushing holes. There are parts of a clock movement that exhibit more wear than other parts.
For instance, the wheels that spin the fastest are often the areas that show the most bushing wear but wear can show up in other places as well. I noticed punch marks on the cap side of each mainspring barrel. While punching around any bushing hole is generally poor practice, it appears this was done at some point in the clock’s history and can’t be reversed. Nonetheless, the repair seems to have held up well.
Next Steps
After inspecting and cleaning the movement, and polishing the pivots, the next step is to install new bushings. In my next article, I will focus on this process, along with the reassembly and testing of the movement.
A clock spring barrel is a cylindrical component found in spring-driven clocks. Its primary function is to house the mainspring, which stores energy to power the clock.
The mainspring barrel works like this
Themainspringis a tightly coiled strip of metal that, when wound, stores potential energy. The barrel holds the mainspring in place and allows it to unwind in a controlled manner, releasing energy to drive the clock’s gears and ultimately the hands.
Mainspring barrel
The arbour, a shaft running through the center of the barrel, is connected to the winding mechanism by means of a gear. One end of the arbour accommodates a key, used to wind the spring. The other end of the arbour connects to the movement plate. When wound, the arbour twists the mainspring, storing energy. As the mainspring unwinds, it turns the barrel, which transmits power to the clock’s gear train. And that’s it!
A time-only clock made by Empire with a single barrel
A typical clock may have one, two, or even three barrels.
In a clock with a single barrel, the mainspring powers only a timekeeping train. Clocks with two barrels use one to power the time train and the other for the strike train. In clocks with three barrels, each barrel powers a separate function: one for the time train, one for the strike train, and one for the chime function.
Why remove the mainspring
Part of servicing a clock movement involves checking and cleaning the mainsprings.
Over time, the mainspring(s) can accumulate old oil, dirt, and debris, which can impede its smooth operation. Removing the mainspring from the barrel allows for proper cleaning and lubrication, ensuring the clock runs efficiently.
Removing the spring allows you to apply fresh mainspring oil evenly along the entire length of the spring. But that is not the only reason.
Mainsprings can weaken, crack, or break after years of use.
Removing the mainspring from the barrel allows you to thoroughly inspect it for any signs of wear, fatigue, or damage that might require replacement. If the spring is in good condition but the hook end is cracked, it can be reused by cutting the spring and fashioning a new hook end. However, this will make the spring slightly shorter. This task is best suited for an experienced clockmaker. That said, the most straightforward solution is to simply replace the spring.
If the mainspring is no longer functioning properly (e.g., losing power too quickly, damaged, or completely broken), it must be removed and replaced.
Broken mainspring
Regular maintenance, including removing the mainspring when necessary, helps prolong the life of the clock and ensures reliable running.
Remove the barrel from the clock movement:
Complete disassembly of the movement is necessary before working on the mainspring barrels. However, it’s worth noting that some German clocks are designed to allow the barrel to be removed without fully disassembling the entire movement, provided that only a broken mainspring needs to be replaced/repaired.
Ensure the mainspring is fully unwound before proceeding. If it is still wound, use a let-down tool to gradually release the tension.
The letdown key
The barrel consists of a cylindrical case and a cap. The cap is press-fitted in place and must be removed.
Hold the barrel in a gloved hand with the cap facing your palm (and the arbour between fingers), then give it a quick tap against a block of wood. The shoulder on the arbour inside the cap is enough to be able to supply even pressure to the centre of the cap and pop it off. This method ensures that there is no damage, and no scratches, plus it’s very simple to do.
Exercise caution to prevent bending or damaging the barrel. Although a screwdriver can be used to pry open the barrel, the risk of bending the cap or causing unsightly scratches is too great.
A mainspring winder
Attach the mainspring to a mainspring winder by securing the inner end of the mainspring to the winding arbor of the tool.
Mainspring barrel in Olie Baker spring winder, collar readied for the spring
Wind the mainspring slightly to loosen it from the barrel walls. Insert an appropriately sized mainspring collar and slowly unwind the mainspring into the collar and then gently remove it from the barrel.
Use thick leather gloves to handle the mainspring
Wind the spring again to remove it from the collar and then relax the spring for servicing.
The mainspring is inspected for damage, dirt, or rust. I use a Scotch-Brite scouring pad to clean the mainspring of dirt and debris. After cleaning, I wipe the spring with a soft cloth to remove any residue, and then lubricate it with Keystone mainspring oil.
After servicing, it is time to reinsert the mainspring into the barrel. Wind the mainspring tightly, place the collar back on, and secure the spring within it. Insert the collared spring into the barrel, ensuring the hook end catches on the notch inside. Finally, remove the collar and carefully unwind the spring into the barrel.
Using a mainspring winder such as one made by Olie Baker is the safest and easiest method for removing and re-installing the spring, as it ensures controlled release.
A mainspring can be removed manually, and there are plenty of YouTube videos available that demonstrate how to do it “properly.”
In Summary
It’s important to mention that there are specific barrel issues, such as broken catches or bulging barrels, which fall outside the scope of this article.
The mainspring barrel houses the mainspring and enables controlled energy release to drive the clock’s gears and hands. Proper maintenance of the mainspring, including its removal for cleaning and inspection, is essential to prolong the clock’s life. Regular servicing, including checking for wear and replacing damaged mainsprings, helps maintain the clock’s performance and longevity.
In the fascinating world of horology, many terms and expressions are often misunderstood or misused. A classic example is the frequent confusion between the words “mantel” and “mantle” to describe certain types of clocks. While “mantel” refers to a shelf over a fireplace, “mantle” is something you wear, like a cloak.
Another pervasive myth is the notion of “over-winding” a clock. How many times have you heard, “It was running fine until I over-wound it”? This phrase is commonly found on clock forums, Facebook groups, and among enthusiasts. However, attributing clock malfunctions to over-winding is a misunderstanding of how clocks operate.
American time and strike clock movement
While it is technically possible for a mainspring to be damaged by excessive tightening—winding it until it’s tight and then continuing to wind it further—this is not the primary cause of most clock failures. The real issues often stem from different sources.
Consider the spring barrel, as shown in the photo below.
When the spring is wound, it coils tightly around the winding arbor, with the other end hooked to a small stud inside the barrel. This hook can become fatigued over time due to repeated excessive winding or the riveted stud can break free, but this is not the typical cause of a clock stopping.
In American open mainspring clocks, what appears to be “over-winding” is often a result of old oil, rust, and dirt accumulating in the mainspring coil. These contaminants can cause the coil to stick and seize somewhat like the action of an adhesive, making it “seem” as though the clock is “over-wound.”
This spring is re-useable
When I receive a clock that is said to be “overwound”, I use a let-down tool to release the mainspring partially or completely, apply mainspring oil generously, and then rewind the clock. This step will help in some cases, but it’s important to note that it doesn’t replace a thorough cleaning or address other potential issues that might be causing the clock to stop.
The letdown key
Disassembling the movement and removing the mainspring allows for a proper inspection. Dirt and old oil can be cleaned, light rust can be removed with emery paper or steel wool, and heavy rust necessitates the replacement of the mainspring. The spring should also be checked for cracks or breaks. Often, a mainspring in good condition can be salvaged with proper care even if there are minor problems with the connecting section of the spring.
I frequently reuse mainsprings in my clock repairs, as long as they are not “set.” A mainspring is considered “set” when it has developed permanent deformations or has lost its original flexibility and strength due to repeated use or overstressing. In such cases, reusing the mainspring compromises the clock’s reliability and shortens its operational cycle.
When a mainspring is “set,” I typically replace it to ensure the clock functions optimally and to avoid potential issues. If I were operating a clock repair business, I would replace the mainsprings as a standard practice and pass the cost onto the customer.
“C” clamps used to contain the power of the mainspring
Another potential issue is the click mechanism. In some clocks, such as those made by Sessions for example, the click rivets can become fatigued and fail. Inspecting and repairing/replacing this component is a common procedure in clock servicing.
Worn click on Sessions movement
When buying a new clock, do not assume it has been recently serviced unless the seller can confirm it. If there’s no assurance of recent servicing, plan to have the movement serviced as soon as possible either by yourself or a competent professional.
Regular maintenance is crucial for any mechanical clock to ensure its longevity and proper function.
“Over-winding” is a myth that often misguides clock enthusiasts. The real causes of clock issues are typically related to dirt, old oil, or mechanical wear, not the act of winding the clock. Understanding this can help in better troubleshooting and maintaining your cherished antique or vintage clock.
Mechanical clocks, especially older or larger ones, can pose various dangers during operation and maintenance. In this post, we will cover some of the risks and hazards.
Mainsprings
Do not underestimate the power of a clock with mainsprings. Mechanical clocks often use powerful mainsprings to drive their mechanisms. If these components are mishandled, they can release a significant amount of stored energy suddenly (potential energy), with the risk of causing serious injury.
Mainsprings restrained with “C” clamps
Without the right knowledge and tools, attempting to disassemble or reassemble a mechanical clock can result in damage to the clock and potential injury. When working on a clock and particularly when disassembling clock movements ensure that the mainsprings are safely secured. The best way is to use a specially designed mainspring clamp.
“C” clamps or a strong wire are considered safe methods in clock repair.
Even the simple act of winding a clock can produce a nasty surprise since the sudden release of tension in a mainspring can be dangerous.
I almost lost my thumb when the click let go on the strike side of a Mauthe wall clock while winding it.
Damaged thumbnail but I survived
If I am unsure of the mechanical condition of a clock particularly one that I have recently acquired, I always wind it with my letdown key set. That way I can control it if the click lets go. If I follow that simple rule I don’t get hurt.
A letdown set used to safely wind a newly acquired clock
Gears and sharp components
The gears, escapements, and other moving parts can cause pinching injuries. These parts may also be sharp or have pointed edges, increasing the risk of cuts.
The delicate nature of some clock components, such as thin gears or escapement wheels, can break easily. Working on them without proper knowledge or tools can damage the clock and possible injury from sharp, broken pieces may result.
Mercury
Some antique clocks may contain materials known to be hazardous, such as mercury in pendulums or lead-based solder. Exposure to these materials can pose health risks. For example, most American-made crystal regulator clocks have nickel slugs in glass vials for the pendulum that resembles mercury at first glance. They are completely safe to handle.
Note the pendulum bob in this clock
In contrast, French-made four-glass clocks often contain actual mercury pendulums, which if handled can pose a poisoning risk. The purpose of mercury is to maintain accurate timekeeping despite temperature variations.
The degree of mercury toxicity depends on how much contact one has with it. Here is an excellent article I found on the risks involved and precautions when handling mercury.
Electric clocks
Early electric clocks can pose a significant risk of electric shock if not properly handled or if the wiring is faulty. These clocks are often improperly grounded, and may have worn cords with exposed wire. Those that run hot to the touch when operating are particularly dangerous. Switches and knobs and other components are designed according to past standards and lack the safety protocols of today’s designs.
The danger of electric shock may increase during maintenance or operation.
Sessions 3W electric table clock C.1930
Electric clocks are best handled by individuals knowledgeable about electrical components and their operation.
Radium
Clocks, especially older alarm clocks with luminous dials can pose a significant risk. The culprit is radium. Even a clock that has lost its luminescence may still have traces of radium on its dial or particulate matter that has fallen from the clock-face making them equally dangerous.
As much as you may be curious about how these clocks work, leave them alone and appreciate them as decorations or alternatively, safely dispose of them.
Baby Ben, made in China(a later design with safe luminous material)
It must be emphasized that Inhalation or ingestion of flakes or dust containing radioactive materials is extremely dangerous.
Clock tools and equipment
When working on clock springs or components when there is a potential risk of injury or with tools like a lathe, consider wearing leather gloves, and an apron, along with face/eye protection as needed.
Gloves and safety goggles are an important consideration when working with mainsprings. A winding arbor breaking in a mainspring winder or a mainspring letting go while winding it up might result in the spring, wheel, and arbor flying around the room and possibly toward the repair person.
Thick leather gloves used for spring maintenance
Using a Dremel machine without proper eye protection, especially with wire brushes that rotate at high speeds, can easily lead to serious eye injuries if a piece of wire breaks off.
In sum
To mitigate all risks, it is important to have a good understanding of the clock’s mechanism, use appropriate tools, follow safety procedures, and possibly seek training or assistance from an experienced clockmaker. If you ignore common sense, accidents are sure to follow.
A dirty clock movement ready to be serviced
Those new to clock repair may be eager to dive in and take things apart. However, a slow and cautious approach with a focus on safety will reap benefits in the long term.
Kienzle might not ring a bell for many clock enthusiasts, but it was a major German producer of clocks for the general public.
Kienzle Uhren GmbH, was founded in 1822 by Johannes Schlenker in Schwenningen, in Black Forest region. Jakob Kienzle joined the family by marriage in 1883 and became the sole owner in 1897. He revolutionized clock production through mass production, leading to significant expansion. By 1939, the company employed over 3,500 people and produced around 5 million clocks annually. Kienzle eventually transitioned to wristwatch production and continues to operate as a watchmaker.
Kienzle wall clock C. 1930
This Kienzle wall clock was bought at auction in 2021. It was my second Kienzle, the first, an attractive desk clock from the early 1950s. But in general, I was unfamiliar with the maker. I later learned that the clock was missing some details: a case decoration above the number 12, both standoffs and the pendulum rod retainer was broken. However, the case itself is in relatively good condition.
The time and strike movement in this round top box clock is compact, with a 43 cm pendulum length and a beat rate of 104 per minute.
Kienzle movement
I serviced this movement in 2021 shortly after acquiring it. At the time I found It exhibited typical wear for its age, with the time side running relatively freely and the strike side being somewhat sluggish. After disassembly, an assessment revealed that the movement required 10 bushings: 6 on the backplate and 4 on the front. The work was completed without issues, the movement was reassembled and tested and the clock ran reliably until this year.
Front of movement
Now it has stopped. In short, I’m not entirely sure what caused it to stop.
Suspecting a power issue, I removed the movement from its case and took off the hands and dial face. I also let the mainsprings down but left enough tension to supply power. I unscrewed the crutch bridge to remove the pallets which allowed the escape wheel to run freely. So, not a power issue. I continued to inspect the wheels and pinions and found nothing amiss. While out of the case, I re-oiled the movement.
The issue seems to be with the time-side mainspring. Looking back at my notes, I serviced both mainsprings in 2021 and didn’t observe anything unusual about them at the time. However, I’ve noticed that if I fully wind the time side, the clock is reluctant to start. This issue has happened more than once. Releasing the tension of the time-side mainspring with a wind-down key allows the movement to start running again. If I don’t wind the time side mainspring completely, the clock seems to run without any problems.
I can only conclude that I did not clean the mainsprings as thoroughly as I should have. Residual dirt and grime on the inner part of the coil seem to cause the spring to seize when wound tightly. In the meantime, the solution is not to wind the time-side mainspring fully.
Unfortunately, the mainspring barrels cannot be removed separately as in the case of some German movements, necessitating the complete disassembly of the movement to replace/inspect the mainsprings in case of an issue. If it were feasible to remove the mainspring barrel independently, I would have taken the opportunity to remove the mainspring from the barrel and clean it more thoroughly.
Kienzle movement on the test stand
I am not about to disassemble the clock again as I have more pressing projects on the go but in the meantime, it will run as long as I do not wind the time-side spring too tightly.
Among clock collectors and admirers, the Hamburg American Clock Company is a well-known German company. It is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU and in many parts of the world, it is simply known as HAC.
In this post, I will outline the procedures involved in servicing the movement of a HAC mantel clock produced circa 1925. It’s worth noting that HAC crafted clocks for international markets, and in the case of this particular clock, it spent a period in England after its initial manufacturing.
Time and strike mantel clock made by the Hamburg American Clock Co. known as HAC or HAU
Disassembling the movement
After removing the clock hands and releasing the six screws that attach the movement to the front dial board the movement can be maneuvered carefully around the bronze rod gong without having to remove the gong itself.
Front of type 36 HAC movement
Once out of its case, the first step is to remove the suspension spring and pendulum leader. A taper pin secures the spring onto the suspension post.
Next, safely let down the mainsprings using a letdown tool. On this movement, and I have not seen it elsewhere, there is a small pin on each rachet. Once the letdown tool is placed in the arbour, it is a simple matter of pushing the pin on the click with a small screwdriver and allowing the rachet to run freely, under control, of course.
The pin is indicated by an arrow
At this point, the two exterior wheels, both rachets with their retainers and the click springs can be removed as well as the “V” shaped stop lever.
On the front of the movement, two screws hold the pallet arbour plate, and with it comes the crutch. Note the position of the small pallet arbour plate for future reference. This is also a good time to remove the hammer from its arbour but the plates can be separated with the hammer still attached.
At this stage release the 4 nuts holding the movement and the back plate can be removed. There are two springs which look like stiff wire, one is for the count lever and the other for the hammer. Do not break these springs and be careful handling the plate once it is separated. The wire springs can be repaired if they break but it adds more work to servicing.
Plate is removed
Once the plate is lifted from the movement, the wheels and levers can be removed. Strike and time side wheels are then separated into containers. I like working from the top down and carefully removing each wheel one at a time. The centre cannon is the last wheel to be removed. The half-hour cam, a star wheel with two points, is on a tube which can be pulled off the arbour and the centre wheel easily lifts out. Once the centre cannon is removed the mainspring barrels can be extracted and put aside for servicing.
Assessing wear
Identifying whether a movement has undergone previous work can be challenging, but scratch marks around pivot holes typically suggest past work. An unmistakable sign of prior servicing is the presence of punch marks, as observed around the mainspring barrel on the time side. The aggressive punching suggests that the arbour hole was enlarged considerably. However, the arbour’s fit through the barrel appears sufficiently tight, indicating no immediate concern.
Time-side mainspring barrel showing punch marks
While it’s not approved today, punching pivot holes was a common practice in the past.
The movement is relatively clean but over-oiled the result of simply lubricating the clock over the years without actually checking to see if it required new oil.
There are very few issues with the movement with a potential need for two new bushings on the strike side and just one on the time side.
Cleaning the movement parts
Cleaning a clock movement’s parts is a fundamental step in the maintenance and restoration process. It not only improves the immediate performance of the clock but also contributes to its long-term durability and accuracy.
Cleaning a mechanical movement’s parts before reassembling a clock movement is crucial for several reasons, to remove dirt and debris, prevent wear and damage, optimize performance identify and any perfomance issues. Cleaning is often accompanied by the application of fresh lubrication to key components. Lubrication reduces friction between moving parts, minimizing wear and ensuring smoother operation. This step is vital for maintaining the health of the movement.
Last week I began working on a Junghans round top mantel clock. For first impressions and background information about the clock itself, you can find the article here.
During this segment of the maintenance process, my attention will be focused on the mainsprings.
Upon my initial assessment, it appeared that the movement was found to be in decent condition, overall. A noticeable accumulation of dirty oil in the majority of pivot holes told me that a thorough cleaning was necessary.
Junghans movement with the back plate removed
Upon closer inspection, elongated pivot holes in three locations tell me that new bushings need to be installed: specifically, on the third wheel time side, back plate, and both the front and back plates of the star wheel. The star wheel runs off the count wheel and it is the star points that activate the hammer for the strike.
But first, let’s focus on the mainsprings.
In my experience neglecting certain steps during clock servicing can result in potential future complications.
One side of the barrel is open
For example, there is a temptation to overlook the mainspring barrels, yet it becomes evident that unless one is confident about the absence of accumulated dirt and grime within the spring barrel, certainty can only be achieved through disassembly. Moreover, the open design of this particular barrel increases the likelihood of dirt penetrating the springs.
While mainsprings can be removed from their barrels by hand and subsequently coiled back in by hand, a mainspring winder, such as one made by Olie Baker, is an essential tool for the serious repairer.
Time side mainspring on an Olie Baker spring winder, an appropriately sized collar is on the right
Removing and reattaching the caps to any barrel can be quite cumbersome. With this particular barrel, a convenient and swift method involves using a small slotted screwdriver in one of the two small openings to easily pry open the cap.
A small slotted screwdriver is inserted in the opening to pry open the cap
The importance of wearing leather gloves for safety cannot be overstated.
Tightening the mainspring allows for the insertion of the collar
A firm grip on the barrel ensures a predictable and controlled process.
The collar is in placeand the spring can be let down and removed from the barrel
During the removal of the mainspring, a thorough inspection is conducted to identify potential issues such as stress cracks, unusual wear, pitting, and the accumulation of rust. Subsequently, the spring undergoes a meticulous cleaning process to eliminate any dirty oil, followed by reoiling, before being reintegrated into the barrel.
Reattaching the cap to the barrels can be accomplished by employing two small clamps to gently guide the cap into position.
Two clamps help to guide the cap in place
Once more, the use of gloves guarantees safety.
Upon proper placement, the cap will emit a distinctive “snap” sound.
Both mainsprings have been serviced and the barrels cleaned in the ultrasonic machine
The springs in this particular clock appeared to be in excellent condition and are suitable for reuse.
Meanwhile, it is essential to inspect the barrel teeth for signs of wear, particularly focusing on any bent or damaged teeth during this stage. Worn teeth may result from a spring that is too powerful and not correctly rated for this clock, while broken or bent teeth could be indicative of a mainspring failure.
Next, we proceed with the remainder of the maintenance for this time and strike clock, moving on with the polishing of pivots and bushing work. Join me in a few days as we continue the servicing of this Junghans movement.
The example is a Fleet time and strike mantel clock from the 1930s. Fleet Time Company of Montreal, a company that was operating four short years, sourced movements from Germany prior to the Second World War. It was a very common mantel clock sold through department stores across Canada.
I like the step side design and the general simplicity of the clock.
Fleet Time case, refinished
The case was in need of refreshing but the movement looked to be in reasonably good condition and required a good cleaning and I was expecting some wear.
The movement was completely serviced with several new bushings installed. The mainsprings were removed, cleaned, and returned to their barrels.
Fleet time movement
In this movement, the mainsprings can be removed without disassembling the movement, handy for such things as replacing a broken mainspring assuming, of course that nothing else has been damaged.
During the testing phase, the mainsprings were partially wound. The intent was to see if the clock would run well. Once satisfied that the movement was running as it should I returned it to its case.
I wound the strike side fully and then wound the time side. Just as I was feeling resistance, CLUNK, the arbour turned freely. If it was a broken click or broken mainspring, either one could easily be replaced.
It has nothing to do with the force of winding a movement. Having a mainspring go bad with winding force from a key is rare, in my view.
But mainspring barrel teeth do not simply fall off.
Fleet time barrel
At times it is a mainspring but sometimes something far worse occurs.
It is not uncommon to find secondary damage to the movement, secondary or collateral damage due to the extreme shock that broke or bent the teeth and teeth cannot be straightened.
The main problem area beyond the barrel itself will be the second wheel and possibly the third wheel arbors, leaf pinions and pivots and/or damaged or missing teeth on the second and third wheels and bent or broken pinions.
Fleet second wheel, a bent leaf cannot be unbent
Is it fixable? Yes, but weighed against the value of the clock, it is just not worth it. It is much more cost effective to harvest parts from another movement.
Given the right equipment, it can be repaired. Once repaired a mainspring must be sourced and although the barrels may be identical, the mainsprings will likely be different.
The solution is locate a donor movement. In the meantime the clock has been put aside.
Let’s clear something up right away: I am not a “Dunkin Swish” enthusiast. If you’ve been researching the clock-collecting world for a while, you might have come across this term. If you haven’t, consider yourself lucky—it’s something best avoided at all costs.
“Dunkin Swish” (apologies to those named Duncan) refers to the practice of placing an assembled movement into a cleaning solution or an ultrasonic cleaning machine, drying it off, and then declaring it “clean.” This is the absolute worst method for cleaning a clock movement and is never a good way to clean mainsprings within their spring barrels.
Why? Only by disassembling the movement can you properly inspect parts, polish pivots, peg holes, and thoroughly remove the dirt and grime that accumulate in the small crevices of a movement—buildup that will accelerate wear over time.
There is only one method to properly clean a clock movement, and complete disassembly, which includes removing mainsprings from their barrels/arbours.
Here are the steps I always follow when cleaning clock parts.
Hermle movement parts after cleaning
In most cases, clock parts can be safely cleaned using an ultrasonic cleaning machine. However, in rare instances, when working with something very old and delicate, hand cleaning may be the only viable option.
For the purposes of this article, I will assume that most clocks you work on are standard common-place brass mechanical movement types found worldwide.
Let’s get started.
Pre-cleaning
Once I have the movement disassembled, I clean any stubborn stains and wipe off excess oil from the parts beforehand. From experience, I’ve learned that while an ultrasonic cleaner works remarkably well, it’s not a magic solution—tough stains don’t always come off easily in the cleaner.
Pre-cleaning has an additional benefit: it extends the life of the cleaning solution. The solution can be reused multiple times, but once it becomes too dirty or cloudy to see through, I dispose of it. Proper disposal can be a challenge, which is why I always opt for a non-ammoniated, biodegradable solution.
I also clean all the pivot holes with peg wood or toothpicks and remove oil from the pivots beforehand. Additionally, I wipe away excess oil and dirt from the mainsprings.
The ultrasonic cleaner
In the early days of my clock repair work, I used an inexpensive ultrasonic cleaning machine. It was adequate for small jewelry items and acceptable for clock parts, but as I could afford something better, I decided to invest in a commercial-grade product.
Ultrasonic cleaner
I came across many Chinese-made ultrasonic cleaners on Amazon and eBay. While some may have had positive experiences with these machines, and the prices are certainly appealing, I was looking for something of higher quality and with a solid warranty. I have no issue with Chinese ultrasonic machines, but I would only consider them if they offered a reliable return policy and warranty.
I chose L&Rfor two main reasons: their reputation and warranty. I get no credit for mentioning this company, but the link will allow you to explore their product line to find the right size for your needs. After four years of continuous use, my L&R cleaning machine has performed flawlessly. L&R meets all of my requirements.
L&R Quantrex Q140, 3.2L with heater
The Q140 with heater is the size I opted for. It will hold one complete movement but is a tight fit for larger movements. Its smaller size means less cleaning solution is used and quicker heat-up times.
A high-quality ultrasonic cleaner will not disappoint. While there may be other brands that are equally good or even better, you generally get what you pay for.
Using an Ultrasonic Cleaner
Ultrasonic cleaners use cavitation, generated by ultrasonic waves, to clean objects made of non-absorbent materials. Ultrasonic cleaning effectively removes dirt, grease, and other contaminants from delicate components without causing damage. Just look at how bright and shiny this 30-hour movement looks after ultrasonic cleaning. That said, achieving an absolutely shiny movement is not the goal.
30-hour movement after cleaning in Ultrasonic
Should everything go into the ultrasonic cleaner? Avoid mixing metals beyond brass and steel in the cleaner as they may react with each other. I also avoid placing anything plastic in it. Some modern clock movements with plastic or nylon gears and parts should be cleaned separately and not placed in the ultrasonic cleaner. Hammer heads made of leather should not be placed in an ultrasonic.
Use your own judgment with friction-fit parts, such as a center gear and pinion, as there is a risk of damaging them if you’re not confident they can be reassembled easily. Otherwise, disassemble as much of the movement as possible.
Choose the Right Cleaning Solution
Avoid using flammable substances such as alcohol, gasoline, or other volatile liquids. These can vaporize, potentially causing a fire or explosion, and release harmful gases into the workspace. Inhaling these toxic fumes is never safe.
Only solutions that are specifically designed for an ultrasonic cleaner should be used. Among acceptable cleaners is Polychem Deox 007 as a cleaning solution that works effectively. The mix is 5 to 1 ratio with water and it is free of odour. According to their product brochure Deox-007 is “an environmentally friendly, non-ammoniated concentrate cleaner. It is mildly alkaline for the efficient removal of oils, grease, tarnish, stains, corrosion, and oxidation from brass, bronze, copper, gold, and silver”. Once it has outlived its usefulness it can be safely dumped down the drain.
Wire basket holding an American-style movement in the ultrasonic before thesolution is added
Many cleaners have a safe fill line, typically about 1 inch from the top of the tank. Whether you’re cleaning one part or several, always ensure the solution reaches this fill line.
A stainless steel wire basket is also necessary as it is not advisable to place parts directly on the bottom of the cleaning tank. A stainless steel wire basket is necessary because placing parts directly on the bottom of the cleaning tank can cause them to become damaged. The basket keeps the parts elevated, allowing the ultrasonic waves to clean them evenly without contact with the tank surface.
Not quite dirty enough to throw away
Although I always drain the solution after each use, I understand for the sake of convenience why some repairers leave it in the tank if the ultrasonic cleaner is used daily.
No cleaning method I’m aware of is as effective at cleaning lantern pinions as an ultrasonic cleaner. The results are truly remarkable.
The Ultrasonic Session
I pre-heat the solution which involves pouring in the solution, turning on the heater, and allowing the ultrasonic to come up to temperature. It takes about 10 minutes.
Green heater switch
I typically run the ultrasonic for 20-30 minutes, which is usually sufficient for most jobs. On rare occasions, I’ve run parts through a second time.
Next is drying all the parts and this is where speed is essential. It is surprising how quickly rust forms on the steel parts. I use shop towels and for difficult locations such as lantern pinions, I use a hair dryer. Occasionally, if my wife is baking I will put the parts in the oven during its cool-down phase.
Years ago, some repairers salvaged parts from discarded hot-air popcorn machines, but I don’t see those around anymore. Additionally, in the past, some repairers designed heat boxes using a light bulb, but today’s LED bulbs run far too cool.
Sessions mainsprings are cleaned and ready to be re-installed in the movement
If you choose to place mainsprings in the ultrasonic cleaner, it’s important to dry them as quickly as possible.
There are two reasons why you might prefer to clean them by hand. First, they can be easily cleaned on a spring winder, and second, the solution will become dirty very quickly, shortening its lifespan.
Cleaning a mainspring
One could clean in phases—first the time side, then the strike side—if drying is a concern. Ultimately, it’s up to personal preference.
Using a small metal lathe to buff the Wheels
To buff the wheels using a small metal lathe, securely mount the wheel on the lathe’s spindle and gently apply an emery board to the wheel. Run the lathe at a low speed, applying light pressure to achieve a smooth, shiny finish.
Next, clean the pivots with an emery board. To clean the pivots with an emery board, lightly hold the board against the pivot while moving the emery board up and down at a low speed. Use gentle, consistent pressure to remove any grime or oxidation without altering the pivot’s shape or surface. Use a soft cloth to wipe off any excess residue from the pivots.
Polishing a pivot
Next Steps
Once everything is dry, the next phase involves any necessary bushing or pivot work, followed by reassembly and testing.
So, that’s the method I follow. If you have a different technique or additional steps that you include in your process, I’d love to hear about them.
About a year ago I picked up two clocks. I had my eye on one, an Arthur Pequegnat Canuck shelf clock, and the other was “thrown in” as part of the deal. We completed the transaction on the Pequegnat clock and the seller asked me if I wouldn’t mind looking at a mantel clock stored on a shelf in his garage. He said, “for $10 more you can have this”. I did not know the make at the time but for $10, why not! It was in sad condition as you can see in the next photo.
Fleet clock with a worn finish
A tin plate affixed on the back of the clock told me what it was made by the Fleet Time Company of Montreal (Canada).
Many of these clocks were sold at department stores across Canada during the pre-war (WWII) era. However, this little-known Canadian clock company had a brief life span. Between 1936 and 1940 the company produced a range of two and three-train mantel clocks with movements sourced from Germany but were forced to end their operations when the war began.
Fleet Time Co. label
The Second World War took a heavy toll on this company as the source of movements dried up and so did the company’s fortunes.
Wood cases were made in Canada for some models while other cabinets were imported from Germany.
Servicing the movement
I had completed work on the case a few months ago and now it is time to service the movement.
3 train Fleet movement by Gufa
The clock has a Gufa Westminster chime movement. Gufa is the Guetenbacher Uhrenfabrik, located in Gütenbach, Germany. They manufactured 400-day clocks, cuckoo-clocks and later they became the “Jahresuhrenfabrik” (August Schatz & Sons in Triberg, Germany). Gufa is not a name horologists come across very often in North American. There is a chime gear patent date number ending in 34 which likely refers to the year 1934 indicating manufacture between 1935 and 1939. It is a solid, well-built movement.
Assessment of the movement
I had replaced the time mainspring shortly after I bought the clock but I knew that I would eventually have the movement on the workbench. As is typical of German clocks of this period in that the mainspring barrels can be removed without dismantling the movement, so, replacing the time mainspring was an easy fix.
The clock was running, though not well. On the fourth or fifth day, the chimes (and strike) would stop though the time train would soldier on a few days more. Wear issues on the strike and chime train had to be addressed.
I disassembled the movement, put the parts into the ultrasonic cleaner, and discovered afterwards that the plates had been lacquered. With the ultrasonic heat setting on, the lacquer stripped off but not uniformly. As it is a $10 clock I am not concerned about aesthetics.
Fleet movement wheels tied together according to location
To eliminate the chance that I would mix up the wheels for the 3 trains, I tied each set together. Once out of the ultrasonic cleaner I untied them and placed them in their respective trays. Westminster chime movements have similar-looking gears in the three trains and it is best to separate them to avoid frustration during re-assembly.
After inspecting the movement I determined that new bushings were required on the second wheels plus the motion works arbour. Three of the second wheels on the backplate, one bushing for the strike side second wheel front plate, and one for the motion works for a total of 5 new bushings; not bad for a 3-train movement. These are the typical wear points on three-train movements as the second wheels handle the greatest load.
Bushing work
Once the pivot holes were pegged out and the wheels rechecked in their locations, the bushing begins. Aside from the second wheels, most other pivot holes were in good shape. I don’t often use bushings with an outside diameter of 4.50mm but this movement required 4 in total. All bushings had to be reamed out with a cutting broach followed by a smoothing broach. All wheels were test fit with the plates together and things looked good.
Reassembly
Next is reassembly. With so many wheels it is a bit trickier than a two-train movement but it is important to work slowly and carefully to avoid a bent pivot. Once the wheels are positioned, test each train to check that everything is in place. After the nuts are tightened, the remaining parts such as the locking plate, chime locking lever, warning lever, rack snail, mainspring barrels and so on are installed/attached.
Testing
Of all movements, three trains are the most difficult to set up correctly. Although all three trains spin independently they are interconnected by levers. In order for everything to function in unison, careful attention must be paid to the job of each lever, what it does and how it performs its function every 15 minutes.
Gufa movement, front plate showing rack, snail, levers, and so on
Everything went fairly smoothly. Both the strike side and chime side go into warning as they should, the locking plate stops the chime at each quarter-hour including the hour, which is a good sign the locking hook on the chime train is in the correct position.
Gufa movement on the test stand
The chime strike lever is, however, sticking on the strike warning pin. Without taking the movement apart I used 1600 grit memory paper to smooth the hook end surface where it meets the strike warning wheel pin. The polishing allowed it to function a little better but continued testing revealed that that solution did not work. I finally had to remove the chime strike lever and polish the hook. the polishing was successful.
The next issue is the strike paddle which is ending the strike sequence hanging off one of the star points. The plates on the strike side must be opened up and the paddle repositioned. For safety reasons and to preserve the mechanism should things go awry, the power is let down on all mainsprings. Adjustments such as these come with the territory as nothing should be expected to work perfectly the first time.
Gufa movement, the upper wheel is the main chime wheel
After the aforementioned adjustments are made, next is the chime sequence and that means loosening the set screw for the main chime wheel and rotating the drum till the quarter strike is at the 1-2-3-4, the beginning of the sequence.
Once the adjustments have been made it is back to the test stand.
Okay, my strike paddle adjustment did not work but in the meantime, the testing of the movement proceeded and everything looks very good at this point. I will give it a few days and return to re-adjusting that paddle.
Everything is working now.
I’ll be honest, 3 train movements are not my favorite type to work on for 4 reasons. One, they often need major work only after a few years. Secondly, it is often not enough to install new bushings for worn pivot holes lower in the trains but to address other worn holes up the trains, as well. Thirdly, they are labour intensive and finally, except for modern movements, parts are almost impossible to find.
In many cases, certainly as far as a modern Hermle is concerned, it is often more cost-effective to simply replace the movement rather than repair it.
The world of horology reveals an assortment of interesting expressions as well as the misuse of words and terms. For classic example; why do some refer to shelf clocks as Mantle clocks when a mantel is something you wear like a shawl or a cloak? Mantel, such as a shelf over a fireplace, is the correct term.
I want to focus on one very common expression. How many times have you the heard the expression, “it was running fine till I over-wound it”? I have heard it often enough on clock forum, Facebook sites and among acquaintances. It is an ubiquitous expression. Do not blame the last person winding the clock for they are not the cause of a so-called “over-wound” clock or one that stops mysteriously.
Over tightening
While it may be technically accurate that a mainspring can become damaged by repeated over-tightening that is, winding the spring until it is tight, and then continuing to tighten it more just to be on the safe side, there is another reason why this occurs.
Take a spring barrel like the one in the following photo.
Barrel and winding arbour
When the spring is wound it is coiled tightly around the winding arbour. The other end of the spring has a small hole which is hooked over a small stud, which is riveted into the interior wall of the barrel.
The hole allows the spring to be hooked to the inside of the barrel
The hole in the spring can become fatigued because of years of repeated “over-tightening”, and/or the stamped hook or riveted stud breaks free. “Over-winding” is not the reason.
A dirty movement
American open mainspring clocks “appear” to be “over-wound” because of a buildup of old oil, rust and dirt in the mainspring coil which causes the coil to stick and the spring to seize.
Clocks which might appear to be “over-wound” and non-working can be persuaded to run again by letting down the mainspring completely with a let-down tool, liberally applying mainspring oil and rewinding. This procedure is by no means a substitute for a good cleaning and it does not address other issues that may be causing the clock to stop but it is one step in troubleshooting your clock movement.
It is only when the movement is disassembled and the mainspring is removed from the arbour that you can examine the condition of the mainspring and decide whether to keep it or replace it. Dirt and old oil can be easily cleaned up. Light rust on a mainspring can be removed with emery paper or steel wool; heavy rust and the mainspring should be replaced. Inspect the spring for cracks or breaks. In many situations the mainspring can be saved.
In some cases the click can let go because the rivet securing the click becomes fatigued. For example, Sessions clocks have weak clicks and rivets. Inspection and remediation of a bad click is a typical procedure when servicing a Sessions clock.
Open mainspring click riveted in place.
Do not expect a newly acquired clock to have been serviced recently or at all unless the seller can prove it. Moreover, servicing a mechanical clock on a regular basis is an important part of ownership.
“Over-winding” is one of those terms that one hears quite often and is a very common myth.
Most refer to the name “Horse Crown” when describing this clock and it is easy to see why. Many would also consider it a Vienna Regulator style of clock. I have been putting off servicing this movement for a while and a long time has passed since it was properly serviced. So, let’s get started. First, some background.
Mauthe “Horse Crown”
The clcok was complete save for a missing bottom centre finial. I installed a new one shorty after I bought the clock
Clocks such as these are often missing not only a finial or two but the crown and other parts so this clock is in good condition.
Replacement middle finial
Year it was made and a history of the company
From my research, the trademark on the front plate tells me that the movement was made between 1895 and 1914 though the exact year of manufacture is unknown. Mauthe trademarks are very distinctive and from the trademark design, one can place the clock within a specific period of time. Unfortunately, the production number on the movement is a mystery as there is no known database for Mauthe clocks.
Trademark, production number, length of the pendulum (34cm), BPM (116) & patent number
Mauthe clocks have had a long and illustrious German history. In 1844 Friedrich Mauthe and his wife Marie founded the company in Schwenningen to produce watch parts. They were very successful through the years and diversified in several areas but after 1946 following the production of wrist watches the company gradually fell into decline.
This clock reminds me of what Forest Gump once said, “life is like a box of chocolates, you never know what you are going to get”
Now let’s open it up
The clock hung on my living room wall for three years. When I bought it I knew that it would eventually require servicing but there were so many other projects on the go, it could wait. The clock ran for several months at a stretch and there were months that the clock did not run at all. So, now that other projects have been completed the time is right for a thorough servicing.
Mauthe wall clock with new bottom centre finial
Forest Gump once said, “life is like a box of chocolates, you never know what you are going to get”. When inspecting any antique clock movement for the first time I have learned to expect just about anything.
As I move through any project my intent is not necessarily to correct mistakes of the past since they are an important part of the clock’s history but to ensure that past repairs do not cause me grief in the future. If it is a crude but functional and sturdy repair, I will generally leave it alone. I have learned that past repairs are part of the history of the clock.
When I took the movement out of the case I discovered something quite interesting. The dial is not original. Yes, it is a Mauthe dial but not for this clock. Two brass strips are fastened to each side of the front plate to accommodate a replacement dial. The added holes drilled into the side braces tell me that it once has a slightly smaller dial.
I am sure that those of you who are collectors have experienced the dilemma of identity
I am sure that those of you who are collectors have experienced the dilemma of identity. When I bought my first Vienna Regulator I began to realize that many parts were replaced over the years and it made me wonder what is original and what is not. It as an unwinnable argument and I have learned to accept the notion that it may not matter to me or to a casual observer who would not think of questioning whether a clock and its parts are original.
Two extensions, soldered to the sides to accommodate a replacement movement
But, let’s move on. A repair was made to the strike hammer which appears to have broken off at one point. Again, a rough but solid repair.
Hammer repair, you can see a pool of oil on the pivot to the left
The clock was coated in oil which was dripping down the plates. However, in terms of its general condition, there is surprisingly little wear. Perhaps the liberal application of oil had a hand in preserving the movement but I suspect that it did not run much over its life.
Mainspring servicing using the Olie Baker spring winder
The mainsprings are enclosed in barrels. I opened up the spring barrels to service the mainsprings. The mainsprings are in good shape with no evidence of rust. They cleaned up nicely. Broken mainsprings in German clocks can be problematic. Severe damage can result in missing mainspring barrel teeth and broken lantern pinions when the mainsprings let go, a challenge for any clock-maker.
Top plate removed
Strike side levers, escapement
The movement was disassembled and the parts were cleaned in my L&R ultrasonic cleaner. The springs and barrels were cleaned separately. All parts were washed in warm water and dried. Finally, the pivots were inspected and polished. Although this movement has a count wheel between the plates with levers much like an American time and strike there are no annoying helper springs to frustrate the re-assembly process.
After lubricating the mainsprings with Keystone Mainspring Lubricant, I put the movement together without the levers to check end-shake, meshing and the condition of the pivot holes. Two lantern pinions had some flat-spot wear but not enough to warrant replacement. Two pivot holes are slightly enlarged on the third and fourth wheel strike side but not so bad that they need immediate attention. If I were in the business of repairing clocks for a living I would bush those two and repair the lantern pinions.
Parts are cleaned & positioned, ready for the front plate
To reassemble the movement I secured the bottom front plate nuts to the back plate and then positioned the pivots into their holes working upwards. Once the pivots are in place on the strike side I attach the third nut loosely and continue guiding the pivots and the two lever assemblies in place. Unlike American movement which have larger pivots, care must be taken not to force the relatively small pivots into their holes.
Much like an American time and strike movement, the cam lever must be in the deep part of the cam while at the same time the count hook is in the deep slot on the count wheel. I made a note of the position of the stop wheel beforehand and in so doing managed to correctly position it on my first attempt.
I generally run a movement for an hour or so without lubricant to determine if everything is functioning properly. No point in oiling the movement repeatedly if it has the be dis-assembled to correct an issue. Once I am satisfied that the movement is running as it should, I apply oil to the pivot holes.
Having the movement out gave me an opportunity to clean up the case, paint the gong mount and movement rail and give the entire case two coats of shellac (traditional 1 lb cut). The movement is now reinstalled in the case.
With respect to my comments concerning the pivot holes and lantern pinions, putting the movement on a shorter 2-year cycle will enable me to monitor wear.
I had just completed servicing this German Mauthe time and strike wall clock and everything seemed to be going well. It was keeping good time,striking on the half hour as it should and maintaining a consistent an 8-day cycle.
During my regular Saturday clock winding ritual, I decided to begin with this clock. I inserted the key into the strike side arbour, began to turn the arbour and “bang” went the mainspring. The winding key almost took my thumb off.
I think I am going to lose that nail
Ignoring the excruciating pain I just had to investigate the problem. I took the movement out of the case and took the dial off. Of course, I feared the worst. A sound like that is never good. The barrel seemed undamaged, the teeth were intact, no bent arbours and there did not appear to be any collateral breakage.
Aha!, there it is, a loose click spring. The click released when there was not enough tension on the click to hold it firmly to the ratchet wheel.
My fault entirely. When I dis-assembled the movement I bent the click springs out of the way and did not recheck the spring’s tension. When I re-assembled the movement the click on the strike side was evidently loose but it looked tight enough. I wondered why the strike side ratchet sounded “tinny” but I thought nothing of it. Now I know.
Clicks on Mauthe movement
I increased the tension of the click spring. To be on the safe side I checked and tightened the time side one as well. Both sides now have that reassuring click-click sound. As you can see in the above photo It is not the best click spring design.
A reminder to anyone working on clocks that potential (or stored) energy in the form of powerful mainsprings can be dangerous. All is well, lesson learned. But my poor thumb!
Some folks collect clocks without actually working on them. Collecting clocks and repairing them are two very different things. I know people who would gladly send their clocks out for servicing and don’t seem to mind the extra cost. I like to do my own work.
If you work on your own clocks or service clocks for others you know how important it is to ensure safety at all times. Servicing a clock movement requires that you disassemble it completely and safely. There are specific tools designed not only to make life easier as a clock repair person but will ensure your safety at the same time.
Before taking the pins or nuts from the movement plates there are important steps you must follow to ensure your safety working with movements. There is a minimal threat of injury working with weight driven clocks (unless a weight drops on your foot) so the following information pertains to spring driven clocks be they open mainsprings or springs contained in a barrel. The let-down tool is designed specifically for spring driven clocks.
Click, click spring and ratchet
The letdown key is engaged prior to releasing the click
Some clock movements from French, English and German clocks, for example, contain mainsprings within a barrel, safer than open mainsprings. If the spring lets go in a barrel there is still a risk of damage to the gear teeth and wheels however the break will be contained within the barrel itself. The letdown key is used to release the power of the mainspring into its barrel.
The flat clamps (upper left in photo below) are for those open mainsprings which do not leave a lot of working room. Otherwise, the round clamps are good for most applications. Prior to working on a movement the mainsprings must be letdown or restrained in their clamps.
C-clamps used to contain the power of the mainspring
A flat C-clamp is wrapped around the mainspring as you can see in the next photo.
Mainspring contained in a C-clamp
Once the mainspring is safely contained you can work on it with a spring winder, like this spring-winder from Olie Baker .
Mainspring servicing using a Olie Baker spring winder
Here’s how it works. There are four pieces in the let-down set. There are 3 chucks in sizes #5-6, #7-8 and #10-12 plus the handle. Choose the size that fits the winding arbour of your movement. Then insert the let-down end with chuck into the winding arbour. Turn it until the mainspring is compressed. Fit a clamp around the mainspring. Once the clamp is secure around the mainspring release the click spring with a small screwdriver and push it out of the way. Once the click spring is out of the way move the click away from the ratchet while firmly holding the let-down key. The power of the spring will be transferred to the key. Allow the spring to gradually release its power by letting the key handle spin gently within your hand. There, the mainspring power has been restrained and you will be able to proceed with dis-assembly.
Your journey into the world of clock repair requires essential tools The let-down set should at the top of the list. Always minimize the risk of injury by restraining the power of the mainsprings. The letdown key is the safest method of letting down the mainsprings.
An antique clock stopping unexpectedly can be frustrating, especially if it has been running smoothly for years. However, a stopped clock doesn’t always signal a major problem. In many cases, the issue can be resolved with a little troubleshooting and basic maintenance. Whether it’s a cherished family heirloom or a recent addition to your collection, understanding the possible reasons behind its stoppage can help you decide on the best course of action to bring it back to life.
Perhaps you’ve recently acquired a mechanical clock—whether inherited, gifted, purchased at an antique store, bought online, or one you’ve had for a while—and, for no clear reason, it has stopped working.
Categories of Clocks
There are four general categories of clock movements; quartz, electro-mechanical, electric, and mechanical. This post focuses on mechanical clocks, whether antique or vintage and if your mechanical clock has stopped, I may be able to help you get it working again.
Running Time
It may surprise some that mechanical clocks require regular winding. Eight-day clocks need to be wound once a week, while 30-hour clocks require daily winding. 31-day clocks only need winding once a month, and 400-day clocks, also known as anniversary clocks, are wound once a year. Additionally, many German and a small number of American clocks run for 14 days before needing a wind.
Kundo Standard 400-day clock winds with a key once per year
Arthur Pequegnat Moncton, 14-day time-only clock
Winding a Clock Movement
What does winding a clock actually mean? It means providing enough power to a mechanism that will allow it to run for its designed cycle.
For example for clocks with mainsprings, winding a mainspring implies turning the key until the clock winds no further. Time and strike clocks will have two winding arbours, chiming clocks generally have 3 winding arbours.
Clocks with weights have one, two, or three winding points. Absent the odd exception, a time-only clock will have one winding point, a time-and-strike clock will have two, and a chiming clock will have three. If there are no winding holes on the clock face, it is a weight-driven clock and the weights must be pulled up by hand.
In the case of clocks with mainsprings that provide the motive power for the time, strike, and chimes, wind each arbour until resistance is met and you cannot wind any further.
One key will fit all the arbours except the regulator arbour (on clocks that have this feature) which requires a smaller key. Clocks that have a regulator arbour originally came with a double-ended key; the smaller key is for the regulator.
Clocks generally wind clockwise but it is also common to find winding arbours that must be wound counterclockwise.
Over-winding
The idea of overwinding a clock is a myth. If a clock stops after being fully wound, it typically indicates that dirt, old oil, or grime on the mainspring has caused it to seize. Even if the mainspring, once unseized, has enough power, it still needs cleaning, which requires disassembling the movement and checking for other potential issues.
A clock in good working condition should complete its full cycle, whether that’s 30 hours, 8 days, 14 days, 31 days, or any other duration.
Winding arbors on a Seth Thomas mantel clock (arrows). The arbour over the 6 requires a smaller key to regulate the clock
Why Has My Clock Stopped
First and foremost, all clocks require motive power. Winding a clock stores potential energy in the mainspring, which is gradually released over a designed period of time. This energy is regulated by the escapement, a mechanism that controls the release of the energy in small, consistent increments, ensuring the clock keeps accurate time. Weights resting on the bottom of the baseboard will stop a clock and a completely unwound spring-driven clock will not run.
Is the clock in beat? Put your clock on a level surface. Listen to the tick and the tock of your clock. Try to minimize the sounds in the room you are in so that you can listen closely to its rhythm. It is in beat when its ticks and tocks are even….tick…tock…tick…tock…, and is out of beat when they are uneven, either, tick….. tock or tock tick…… Put another way, there must be an equal amount of time between the ticks and the tocks. When a clock is out of beat, it will not run, or it will run for a short time and stop. A clock’s beat must be regular to work properly.
Is the clock level? There are two ways to put a clock in beat. The first is to tilt the clock sideways, one way or the other, and listen for the beat to even out. When the beat is even, prop the clock to stay tilted that way. If it is a wall clock move the bottom section from side to side till you hear a steady beat. Now it will run in beat but it will obviously not look good.
Adjusting the crutch Adjust the crutch to one side or the other until the beat is even. The crutch is the rod that extends down from the pallets which rock back and forth on the escape wheel. The pendulum rod passes through either a loop (called a crutch loop) or a forked foot at the end of the crutch as indicated in the photo below. Incidentally, that rod needs to be in the middle of the crutch loop and can’t be tight inside the loop nor too loose. The crutch is attached to the pendulum leader which is then attached to a post with a suspension spring. Other mantel clocks require similar adjustment to the crutch and instructions may be provided on a label or a pamphlet that came with the clock. A clock with a balance wheel or lever-type escapement rather than a pendulum will operate on a non-level surface.
American made time and strike
Have repairs been done recently? Unless you had a friend fix your clock most reputable clock-makers will offer a warranty, typically 6 months to a year. If your clock stops within that time frame, contact the clock-repairer who may offer a few suggestions in the form of adjustments, over the phone before taking it back to the shop. If it still does not work have that person take a look at the clock.
Do you have the correct pendulum? Other than the winding key, it seems to be the item that gets lost the most. If lost or misplaced, ensure you buy a pendulum that is correct for your clock. One too light may mean that it does not run at all, too heavy and the centre of gravity is lowered and the clock might run too slowly. Clock suppliers such asPerrin or Timesavers will have the correct pendulum for your clock.
Pendulum bob with an adjuster for a French time and strike
Something is broken? If there is no resistance when turning the winding key, the mainspring has broken or a click has let go. If the mainspring winds but releases in your hand, the most common cause is a broken or worn click spring. This is a repair that requires removing the movement from its case, taking it apart, and replacing the worn or damaged part. If you are skilled with that kind of repair, go ahead and fix it, if not, a specialist is required.
A loud BANG when you turn the key indicates the mainspring has broken or let go. It may not be as simple as replacing the mainspring. If the mainspring breaks it might have taken out other parts with it such as pinions and gear cogs. This is called collateral damage. An inspection and a full servicing of the movement is the only solution. Occasionally a broken mainspring is the only problem but the broken spring must come out of the barrel. Some movement designs allow the barrel to be removed without disassembling the mechanism. Whether the barrel is removable or not, a correct mainspring must be sourced to replace it and installed in the barrel which is a job for an expert.
The mainspring inside the barrel may also have become unhooked. This could occur if the clock was wound backward or if the hooked end of the mainspring is split or broken. To address this, the clock will need to be disassembled, the spring barrel opened, and the cause of the unhooking identified. In some cases, a replacement mainspring may be necessary.
For time and strike clocks with open mainsprings, the break may be on one mainspring or both. The clock must be completely disassembled, mainsprings replaced, the movement inspected for other issues, reassembled, and tested.
Sessions click, brass spring, and ratchet
Why does my weight-driven clock stop? Ensure that the weights are in their correct location. If it is a new acquisition of a grandfather clock the three weights have a specific location. Look underneath the weight shells for marks indicating their location “L”, left side, “C”, center and “R”, right side. If there are no markings, use a scale to determine the one that is the lightest weight and put that on the left side.
Ridgway grandfather clock
When bringing up the weights to the top of the clock be careful that they are not run past their stops. You should have a full view of the weights on a weight-driven clock once wound.
Antique Ogee clocks and other weight-driven shelf clocks often lack their original weights, as these have been lost or misplaced over time. Eight-day clocks typically have heavier 8 or 9 lb weights while 30-hour clocks have lighter 2 1/2 lb or 3 lb weights. Incorrect weights for these clocks will cause them to stop.
Is the weight cord or the brass cable binding in any way? The cord or cable should be just long enough to accommodate the weights. A cord or cable that is too long will bind while being wound and stop the clock.
Gustav Becker two-weight wall clock requires a winding crank
Some clocks like weight-driven Vienna Regulators can be adjusted by a transverse regulating screw assembly where the crutch inserts into a slot in the pendulum. Turning a screw in one direction or the other will correct the beat.
Final thoughts
In conclusion, if you encounter a unique issue not addressed here, it’s advisable to consult a professional clock repairer or someone with expertise in mechanical clock repairs. Working with mechanical clocks carries a certain level of risk, as the power stored in the mainsprings can cause injury if not handled carefully. On the other hand, weight-driven clocks generally present less risk.
Although this article may not cover every possible scenario, I hope it has provided you with a clearer understanding of your clock’s issue and how to approach its resolution.
There is no maker’s mark anywhere on the case or the movement
The clock is an unsigned 8-day carriage clock in a rectangular brass case. This attractive little clock has a white enameled dial with Roman numerals, blued steel hands and a spring driven time-only movement with platform lever escapement visible through the top beveled glass. The brass case has 4 beveled glass panels complete with a fold-down travel handle.
In taking the movement apart to clean it I can see “73” stamped on the bottom of the case, the case handle, the door edge and 2 or three places on the movement and the letter “B” on the back of the front plate but no maker’s mark. What do the numbers mean? I think it is an internal production stamp. Thousands of these generic carriage clocks were made and I may never know the maker. The only taper pins on this movement are those that attach the dial face to the movement. However, judging from what see and its general construction I would comfortably date this clock to the 1880s.
The movement plates are secured by screws rather than taper pins. Older carriage clocks would have taper pins securing the movement plates. This clock would have been produced for the English market since it has “S”and “F” stamped on the escapement (Slow and Fast). The key has “France” inscribed on it so if it is original, then the clock is French.
Unsigned French Carriage Clock
Time-only carriage clocks are relatively easy to work on although the platform escapement takes a extra care. I chose not to service the escapement at this time.
First, let the mainspring down to release the power. If you take a wound clock apart it can injure you. Some of the compression points between cogs can have a very high gearing so even a weakly wound clock has the capacity to trap or pinch your fingers as well as throwing out and damaging components. I use a let down key that can be purchased at any clock supply house.
Carriage clock platform escapement
Movement side view, re-assembled
Taking the movement out of the case involves releasing 4 machine screws in the base. I use several elastic bands to keep the glass in place while I lift the sides and door off the base. When holding the clock firmly observe the effect of loosening the screws. The pillars have become loose and the glass can now move a little in the frame. If you unscrew all the screws completely without understanding that the glass is loose, it is too easy for the glass panels to slide out and break. They are not easy to replace! I’ll describe my work on glass cleaning later.
There are two screws which hold the base to the movement. Unscrew those and proceed to take off the front face. The enameled face is secured by 4 taper pins. In my case they were difficult to get out so I decided to take the back plate off the movement to allow my pliers inside to release the pins. Removing the platform escapement requires releasing 4 very tiny screws. A precision slotted screwdriver is absolutely necessary. It is best to unscrew all 4 together and leave them in place once off the movement so you do not have to fiddle with them when reattaching the escapement later, unless, of course, you intend to service the escapement.
Back plate after a cleaning
I then separate the plates and inspect the wheels, pinions, pivots and pivot holes. I found a little bit of play in two pivot holes only observable with a loupe but not enough for bushing work. I polished the pivots, pegged the pivot holes and cleaned the wheels, plates and other pieces except the platform escapement in the ultrasonic cleaner.
Assembly of the movement is relatively simple as there are so few gears. Attaching the hour hand was interesting, however. Both the hour and minute hands are pressure fit, but the hour hand was a challenge because I had to use a screwdriver to push the hour shaft forward (gently) through the clock face while simultaneously attaching the hour hand. It was very tight. After a number of tries I managed to press it in securely.
It is actually quite small
Back to the glass. It is also important to put each panel back where it belongs. I discovered that there is a top and bottom orientation to each glass panel, they are cut so fine! There is enough resistance if you try to put the wrong end into the channels you will encounter difficulty. Each glass panel is taken out and cleaned with Windex and, of course, put back exactly how they came out.
Once everything is assembled the clock is oiled, wound and the time is set. Polishing the brass case is the final step. Brasso was used to clean up the brass and bring the clock back to its former glory.
We often cruise the HiBid sites. While they may be wholly Canadian I am sure there are similar sites in the US. HiBid are a hosting service for antique online auction companies and from time to time clocks come up on estate sales.
One day in early February 2017 we were on a Nova Scotia HiBid auction site and noticed a Jauch drop octagon with a PL42 movement. I made what I thought was a reasonably good bid. We had errands to run that day so I just left the bid, got home later and realized and surprised that I had won. It was a good purchase. After running for several weeks I opened the case up and discovered its hidden secret.
Time-only Jauch movement
The clock easily runs a full 8-day cycle but it gains about 5-7 minutes at the beginning of the cycle and loses the same at the end of the cycle. A dramatic difference! A properly functioning clock is designed to run at an acceptable rate of + or- 1 minute per week but this depends on adequate power to the escapement with very little fluctuation in that power.
Scored pivots and worn barrel arbor holes are real issues for this movement. The pivots are small, a light touch with a buff stick and a minimal polish along with pegging and round broaching the holes should be the first steps in reviving this clock. Bushing work is also quite possible. The barrels are another matter. If worn, they require bushing. The cap is too thin to bush without making a thin flange or leaving the bush a bit proud and peening both sides. The barrel is narrow and it is said that they really get the wobbles when worn.
This is an inexpensive German movement but finely made and well engineered. An overhaul should result in a good long run.
I took the movement apart and discovered two things. One, it needs at least 3, perhaps 4 bushings and secondly, there is a significant gap in the barrel cap as seen in the photo below.
Barrel cap showing a wide gap caused by wear around the arbour, weak point of this movement
Front plate is removed showing going train
The real issue for me is the barrel cap. I can attempt to bush the cap but the bushing would likely not hold unless it is peened. The gap is causing an unbalance in power transmitted through the gears as a result of the wear. The soft brass barrel cap is definitely a weakness of this movement. The result is the erratic running described above and a wobble in the pendulum. I contacted a gentleman in Arizona who would be prepared to correct the wear by installing two new bushings on the gear side and cap of the barrel. The cost is 1 1/2 times the value of the clock so I have decided against that option. It is just not worth it!
1 Day Later
I installed 3 bushings. The front side of the escape wheel arbour, the front side of the second wheel and the minute shaft. I re-assembled the movement, oiled it, adjusted the pallets, reinstalled the worn barrel and have put the movement back into its case. It is now running and in the next week or two I will see what effect new bushings will have on the running of the clock. My hope is a marginal improvement given the worn barrel.
A barrel repair will have to wait until I have the proper tools.
In a precious article I wrote about my frustrations getting this clock to run reliably. No matter what adjustments I made it ran poorly.
“You’ve got to be very careful if you don’t know where you are going, because you might not get there”, Yogi Berra
This time and strike movement (Hermle?) has been out of its case and lying in drawer for the past year or so. When I met the seller in a parking lot some time ago as I handed him $20 for this Dugena mantel clock he climbed into his car he said, “I hope you don’t expect much for $20; it’s not perfect”. Well, it’s not perfect.
It was keeping poor time, losing an hour or so a day but I thought, what a great clock to practice on and practice I did.
Oiling the movement had no effect. Issues? A weak spiral spring, a worn jewel on the floating balance, a power issue associated with a weak mainspring or perhaps pivot wear. I disassembled the movement several times and serviced the mainsprings. I had an issue re-hooking the strike side mainspring and so, discouraged, I put it aside.
Dugena time and strike German made mantel clock
Dugena – is it a clock company?
Dugena was a German retail clock name only, a marketing name, not a maker of movements or cases. Dugena was a registered cooperative society, a “Genossenschaft”, that bought clocks from other makers to sell them under their own brand. A brand name for a retail chain more or less.
Dugena floating balance
The clock runs slow, this bent spiral spring does not help
Floating balance clocks are much more accurate and above all, they do not have have the disadvantage of the pendulum; these clocks work even when the case is at an oblique angle
A great invention – the floating balance
The floating balance movement in this clock could have been made by anyone; Urgos, Jauch or Hermle perhaps. Hermle is likely since it was one of the leading companies using the floating balance escapement. The floating balance was invented in the 1930s but it took till 1941 for the patent application to be registered. It took another 10 years after that for the patent to be granted slowed by the war years and the challenges of industry recovery following the Second World War.
The floating balance was a great invention. Floating balance clocks are generally more accurate and above all, they do not have have the main disadvantage of the pendulum; they will work even when the clock case is at an oblique angle.
Time and strike movement, maker unknown
Back to the the clock
Months passed. I took the movement out, looked at the strike side barrel a second time, popped the barrel cap off and using pliers gave the inner part of the mainspring a turn and it hooked onto the catch. Success at last. The mainspring barrels can be removed without dis-assembly of the movement, so, in it went. Despite my minor triumph with the strike-side mainspring, straightening the spiral spring and adjusting the balance wheel to its fastest set point, the clock ran only marginally better. The only consolation is that although it runs 5 minutes slower per day it runs a full eight day cycle.
Despite the minor disappointment it has been a productive learning experience but I am inclined to put it aside as I have other projects on the go. Every time I think about the issues I am having with this clock it always comes back to the balance wheel.
In this age of everything electronic, it may surprise some people that a newly acquired mechanical clock bought at the local garage sale, flea market or antique store needs to be wound on a regular basis. Winding a mechanical clock takes a level of care but a few simple guidelines should have you on your way.
Here’s how to wind an antique or vintage mechanical clock correctly. By following these tips and guidance, you’ll gain the skill and confidence needed to wind your clock properly and maintain its functionality.
A typical German mantel clock
Let’s begin by discussing some terms.
Winding Arbours or Winding Points and Their Function
On your clock’s dial (excluding cable-driven tall case clocks), you will notice one, two, or three holes, known as “winding arbours” or winding points. Each arbour serves a specific purpose, and the number of winding arbours indicates the number of gear trains (or sets of gears) in the clock.
For example, a clock with one winding hole is a time-only clock. Two winding holes typically indicate a time-and-strike clock. These clocks strike the hour on the hour and may also strike on the half-hour, either on a bell or gong. Clocks with three winding arbours chime on the quarter-hour, producing a musical tone. On such clocks, the center arbour winds the time train, the left arbour winds the strike train, and the right arbour winds the chime train.
On some clocks, there is a smaller hole on the clock face near or above the 12 o’clock position. It is also an arbour, but a smaller one used for regulating the speed of your clock. If you have a double-ended key, the small end fits that arbour. Some clocks will have the regulating arbour located under the centre cannon where the hands are attached.
The Difference Between Strike and Chime
A strike or a chime is simply the clock sounding the time. An antique or vintage “time and strike” clock indicates the hour by striking once for each hour or using a two-tone strike, such as a Normandy or “Bim-Bam” strike.
On the other hand, a chime is a musical tone and a typical musical tone found on most clocks with three winding points is the Westminster chime. Some clocks provide more choices such as the Schatz W3 bracket clock which has 3 musical tones, St Michael’s, Whittington and Westminster.
On older clocks, there may or may not be an additional strike on the half-hour. Older antique clocks from the mid-1800s, for example, typically do not strike on the half-hour to preserve the wind on the strike side.
Typically, striking clocks have two winding points, while chiming clocks have three.
Where Winding Points Are Located
On this spring-driven, Seth Thomas mantel clock (photo below) the left arbour, indicated by an arrow, winds the strike side and the right arbour, the right arrow winds the time side. The smaller hole just below the centre cannon is for regulating the clock using a double-ended key.
Winding arbours on an antique Seth Thomas mantel clock
On the Ingraham clock (photo below), there is only one set or train of gears that indicates it is a time-only clock, hence the single arbour or winding point. The barely visible, smaller hole in the loop end of the “2” on the number 12 is for regulating the clock.
Winding arbour on an Ingraham Nordic banjo clock
If you find the sound of the strike unpleasant or it disturbs your guests, you can wind only the time side, and the clock will still run perfectly fine without winding the strike side.
However, to ensure even wear and proper maintenance, it is advisable to wind both sides of a striking clock.
The Running Time or Cycle of a Clock
Most clocks are designed to run for eight days. Some older clocks run 30 hours and others run as long as 30 days on a wind. Still others such as anniversary clocks will run 400 days on a wind.
Double-ended Key
For eight-day clocks, winding once a week ensures the clock continues running smoothly. Establishing a routine, such as winding your clock(s) on the same day each week, is a helpful habit. It’s also a good idea to make occasional adjustments to your clock, such as fine-tuning its speed to account for seasonal changes. You can find more details in an article I wrote about regulating your clock.
Clock Keys
It is common for a newly acquired clock to come without a key, and if it does have one, it is usually a replacement. Finding a clock with its original key is quite rare. The key that accompanies the clock is likely to fit, but if your clock has a speed adjustment arbour (marked F-S) on the dial, typically located near the top, it should have a double-ended key.
If your clock has a one-ended winding key and a speed adjustment arbour is present, the key is not original to the clock. Double-ended keys are necessary because the speed adjustment arbour is considerably smaller than the winding arbour.
Key Size and Type
All mechanical clocks require a winding key, like the one shown below. The exceptions are alarm clocks and some carriage clocks, which have built-in winding keys. Keys come in various sizes, so it’s important to have the correct size for your clock’s arbour. The key should fit snugly without being too loose.
If your clock came without a key it can be purchased at any clock supply house such as Perrinin Vancouver, Canada. Timesavers and Merritts are clock suppliers in the USA where keys can be purchased.
Ingraham Huron winding key. Home-made but functional and over 120 years old
Over-winding a clock is a common myth. A clock which “appears” to be over-wound seizes because of a buildup of old oil and dirt in the mainspring coil
Winding Your Mechanical Clock
If the dial is covered by a glass door, open it to access the clock face. Insert the key into one of the winding arbours and use your non-dominant hand to steady the case while winding. To protect the finish of the case, it’s a good idea to wear a cotton glove on your non-dominant hand.
Next, turn the key clockwise. If it doesn’t turn clockwise, try turning it counterclockwise. Some clocks wind in either direction, so this is normal. Avoid forcing the key; apply minimal pressure and continue winding until you feel resistance. Once you encounter resistance, stop winding and do not force the key further.
Below is a clear example of a previous owner using excessive force to wind the movement in the wrong direction. The right spring barrel has become unhooked from the main wheel, which only happens when significant force is applied while winding in the opposite direction.
If you lose the key, simply purchase a replacement. Never use pliers or any other hand tools to wind a clock.
Chinese clock movement
The “clicking” sound heard while winding the arbour is the click engaging the ratchet on the mainspring. The ratchet’s purpose is to secure the mainspring in place with each turn of the key.
An 8-day clock usually requires about 14 half turns of the key as the arbour does one complete turn per day.
Mainspring ratchet and click.
Allow the key to gently return to its click. On the rare occasion that the click slips or breaks, resist the urge to release it quickly. Instead, let the key slowly unwind in your hand to prevent potential damage to the teeth, gears, and even your hand. Letting the key go suddenly can cause collateral damage to other parts of the movement.
The myth of overwinding a clock is common, but a clock that “seems” overwound actually seizes due to a buildup of old oil and dirt in the mainspring coil, which causes the coil to stick. Regular servicing of a mechanical clock is an essential part of ownership and helps prevent future issues.
Clocks with Weights
Not all clocks use springs — for example, grandfather clocks and one-day ogee clocks are weight-driven. On these clocks, the weights must be raised to the top to begin the weekly time cycle. This can be done either by inserting a crank key into the winding arbor on the clock face or by manually pulling the chains to lift the weights.
For clocks with winding chains, gently pull down on the shorter side of the chain until the weight reaches the underside of the wooden seatboard, stopping at the weight stop bar. Repeat this process for the remaining two chains if it’s a chiming clock. Allow the chains to do the work — do not assist by lifting the weights at the same time. Pushing up on the weights could cause the chain to slip over the winding gear teeth or become unhooked. To protect the brass finish on the weight shells, wear cotton gloves while steadying the weights as they are pulled up.
For tall case clocks with cable drives, use a crank key to wind by inserting the key into each winding hole on the clock face. Turn the key slowly until the weights are raised to the top.
All three weights on a chiming grandfather clock descend more or less together through the week.
On older tall case clocks with weights hidden behind an access door, open the door to watch the weights rise as you wind the clock. As the weights near the top, slow down and stop when you feel resistance.
Thirty-hour time and strike or one-day clocks are typically wound with a winding crank inserted in the dial face winding points once per day. Wind the weights to the top of the case at approximately the same time each day.
Final thoughts
In conclusion, take pride in your mechanical clock and the craftsmanship it represents. Wind it regularly, care for it properly, and have it serviced when necessary. Even if you prefer not to keep it running, cherish it as a remarkable piece of horological heritage.
For visual learners who prefer to see the process in action, I’ve created a helpful video demonstration showing exactly how to wind a clock. You can watch it here:
This is Part II of a multi part series on the Sessions Westminster A chiming mantel clock.
Side view of Sessions Westminster A
Inside the plates they are a conventional Sessions clock. Outside the plates is an entirely different story
Sessions Westminster A clocks are true chiming clocks that play the Westminster chime sequences on the quarter hours and strike the hour count on the hour. The unique design combines the chiming and striking functions in one train powered by a single main spring. Between the movement plates these movements are very similar to other Sessions non-chime (strike only) movements. The going (time) train is controlled by a basic recoil escapement with the strip pallets or verge located between the plates. Inside the plates they are a conventional Sessions clock.
Outside the plates is an entirely different story. At the front of the movement one will notice that this is a rack and snail strike train but it has TWO racks and TWO snails. A look at the back of the movement reveals a small cam in the middle of the plate and a large “player drum” or pin drum. The two racks working together with the little cam and the player drum, which can shift outward to play chimes or inward to strike the hour, is what makes it all work. The chime sequence is self‐synchronizing and with so few working parts, once setup correctly this can be a relatively trouble free movement. (Source R. Croswell’sTaming the Sessions Two Train Clock)
This clock requires servicing for two reasons;
It runs for several minutes or an hour or so and then stops
The striking and chiming is very erratic. It might strike 4 o’clock one hour and 9 o’clock the next and the hammers “hang up” during the quarter hour chime.
There are a number of “exterior” parts that must be removed before separating the plates
Dis-assembly of the Westminster A is conventional however there are a number of “exterior” parts that must be removed before separating the plates. The regulator gearing, verge, drum assembly, hammers and racks as well as other parts are removed one after another. The additional parts add considerable complication to the movement and can lead to issues when servicing. I will describe two particular issues I have encountered in the process of working with this movement. I believe these issues, which I will describe later, are likely what frustrate most clock repair persons when working on the Westminster A.
Rear plate showing regulator, verge and chime drum. Clamp on mainspring
I chose to leave the mainsprings in while taking the movement apart though I contained the power using C-clamps. On this clock the mainsprings can be removed without dis-assembly. This allows the repair person to easily service the mainsprings or the clicks (which are notoriously bad on Sessions clocks generally).
Unfastening the drum and hammer assembly went without issue since there are only two bolts securing it to the plate.
The 2 racks, a unique feature, work together to produce the strike. They are located one on top of the other and are secured to a post.
Two racks stacked on top of each other. The post on the right accommodates two springs
Taking them off requires releasing a pressure washer on the top of the post. They came out easily. However, one rack is missing a return spring which might partly explain the erratic striking of the clock. Such a simple thing that may make a big difference. I may have to buy or fashion a spring.
Rack with spring
Rack without spring. The spring clips into the hole on the rack arm
Specialized tools are needed to remove some parts. Those I don’t have
Two issues.
One, I could not remove the hub supporting the gathering pallet pins seen here. It’s unfortunate because there is more lateral movement of the arbour that I am comfortable with which tells me that a bushing is required. I did not want to risk damaging the arbour and I don’t have specialized tools to do the job. I may have to live with it. However, it may not be so bad once the other bushing work is completed.
Gathering pallet pins
Two, I could not remove the centre cam despite pulling and gently prying.
Centre shaft cam
Again, I did not want to risk damaging the arbour. Specialized tools, such as a puller in this case, are required to remove it. That, I don’t have.
This clock has a unfortunate reputation for soft pivots
I will have to work around these two issues. Pressure fitted parts on any movement are very frustrating when said parts cannot be removed without special tools and this one is a challenge indeed. Re–assembly might be a little frustrating particularly with the centre arbour still attached to the rear plate which may effectively be “in the way” of positioning other wheels in place.
I inspected the pivots on the wheels and they all look good (no tapering) with expected wear for a clock of this period. I was worried because this clock has a reputation for soft pivots and perhaps because this is a later model, Sessions might have been introduced harder steel for the pivots. There is plenty of bushing work that needs to be done, however.
On to cleaning, bushing work, re-assembly and testing in Part III.
This is an antique German Junghans time and strike spring driven clock made in the style of a Vienna Regulator. It came to me as a box of parts. To some a box of clock parts and pieces is discouraging but to me it is a challenge.
Part II of a three part series on my newly acquired Junghans Crispi wall clock.
This is Part II of a three part series on my newly acquired Junghans Crispi wall clock. In Part I described the circumstances by which I came across this clock and it’s incredible story as a survivor of the Halifax Explosion of Dec 6, 1917.
This is a German count-wheel strike typically found in the lower lines of Mauthe, HAC and similar clocks. It is an open plate “bread and butter” movement, not of the highest of quality but well built and reliable. The count wheel is located to the rear between the plates and the mainsprings are enclosed in open barrels. There are no helper springs to worry about and all of the wheels are located in the centre and the upper side of the movement.
As you can see in the next two photos the movement was very dirty and I accepted the risk of running it for a day to see what issues might arise. I gave the pivots holes plenty of oil to mitigate any additional wear. What I found was a sticky hammer assembly that would malfunction intermittently which I attributed to dirt and grime buildup, otherwise the movement ran very well after not having run for 100 years. Imagine all that kinetic energy stored in the springs since 1917.
The movement is relatively easy to re-assemble but I had to install the lower centre wheel, the spring barrels and the centre cannon together with the top plate and then slide the gears in between the plates. Fortunately this process is not as difficult as it sounds but very different than laying the top plate right over the gears as you would in an American movement.
Very dirty movement
Mainspring barrel with years of dirt showing
I gave the pivots holes plenty of oil in the testing phase to mitigate any additional wear
Plates cleaned up well
All the wheels between the plates
I found everything within acceptable limits and decided that bushing work was not required
The accumulated grime of 100+ years came off following the ultrasonic cleaning. In fact I have never seen the ultrasonic solution so dirty. The plates cleaned up very well and I gave them an additional polishing with Brasso. After the parts came out of the ultrasonic I tested the movement for any evidence of excessive play and found everything within acceptable limits and decided that bushing work was not required. The pivot holes were pegged and the pivots were polished.
Springs were inspected, cleaned and oiled
There were no cracks or unusual issues with the mainsprings though I found it curious that they were very clean with no rust. There was also very little lubricant remaining. The springs are somewhat tired as you might expect but I think there is enough power remaining for a full cycle so I decided not to replace them at this point. I applied Keystone mainspring oil to the springs once I returned them to their barrels.
With the movement back together, it is time to adjust the strike side. The strike wheels must be set up correctly with respect to each other ensuring that the third (hammer lifting star wheel) and fourth wheels (the strike cam) align with he count wheel. The warning pin on the last wheel (which actually protrudes from the plate) has to be high enough for sufficient rotation. In order to count the strikes properly this relationship must be right. Unfortunately, I can never get this correct the first time.
The servicing of the movement is not without headaches, however.
The servicing of the movement is not without headaches, however. I bent a pivot on the warning wheel which I managed to successfully straighten out. The hammer arbor paddle was barely touching the star wheel and while trying to adjust it, I accidentally snapped it off along with the retaining spring. Although the clock will go though the strike sequence the gong will obviously not sound. I don’t have the tools to put in a new paddle so I will have to get that attended to somehow. I managed to correctly adjust the strike side but the clock mysteriously stops after about an hour or so. Something is definitely amiss and more investigation is required.
I have had more success with the case restoration that you will read about in Part III. In the meantime I have to constantly remind myself that this movement has not been running in 100 years!
It is time to buy the tools I need for clock repair. I already have a number of basic tools to get me started; pliers, letdown chucks, screwdrivers, etc.
However, my first significant tool is an Ollie Baker Mainspring Winder which arrived from the USA today. It is pictured below. The Ollie Baker comes with an assortment of collars for every size of mainspring.
Olie Baker spring winder
The spring winder will enable me to inspect, clean, and re-install barreled or open springs on all the clocks I will be servicing. My first impression is that it is a robust and well-machined tool that will give years of service. Indeed, one of the most important tools for clock repair enthusiasts is the spring-winder.
I also ordered bushing kit #5488 from Perrinstoday which will enable me to have the bushings I need in order to use the Bergeon Bushing Machinethat I will purchase later on this year.
The Bergeon Bushing tool is “Swiss made” and exudes quality. In every clock, due to considerable wear, the plates have to be bushed from time to time. This tool allows the bushing of plates of various sizes. The kit includes driving punches, centering bit, stakes, and reamers. I can bush by hand which some folks do by using appropriate reamers and files but I know that a bushing machine is a must-have. The first photo shows a clock movement that I had professionally bushed. It required 5 bushings in all in addition to cleaning and oiling and it runs very well.
With these tools, I can progress more seriously into this most interesting hobby.
Antique and Vintage Mechanical Clocks 
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