Troubleshooting A Strike Issue on a HAC/HAU Movement

The maker of the movement is HAU or HAC. The familiar cross arrows trademark of the maker is stamped on the movement, in the middle of the backplate.

HAC was formed in Germany in 1873 by Paul Landenberger and Phillipp Lang and was originally called Landenberger & Lang Uhrenfabrik. The company changed its name to Hamburg Amerikanische Uhrenfabrik (HAU)/Hamburg American Clock Company (HAC) in 1883. The famous crossed-arrows became their trademark in 1892. In 1926 the company went into a cooperative with Junghans and in 1930 they finally merged with Junghans.

HAC/HAU clocks can be difficult to date prior to Junghans acquisition of HAC/HAU in 1930. Once Junghans and HAC began their collaboration in 1926 some of the movements were date coded.

Now on to the adjustment of the movement that is the subject of this article.

Strike Adjustment Required

Earlier in the fall this time and strike mantel clock was serviced. During the servicing six new bushings were installed, all components were cleaned, the mainsprings serviced and the clock reassembled and tested.

_{The movement has been cleaned and serviced}

However, during testing, the movement did not strike correctly. While there can be several causes, the most common of which is a misalignment of the hammer tail with the star points on the star wheel. This issue frequently arises during the reassembly of this type of clock movement.

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. Once the wheels are in place 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.

My usual practice is to position all the wheels and the lever(s) on the plate that has 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 moving around as I position the upper wheels and their pivots in the train.

Setting up the strike side can be tricky. The wheels and levers must be set up correctly or the strike will not function. For instance, the width of the slots on the count wheel tells us that there is no “passing strike” on this movement. In some count wheel movements, for example, in many American-made movements, the half-hour is actuated by a cam on the centre arbour.

The pin-wheel, which is uppermost and one wheel removed from the fly on the strike side, is placed in approximately the 10 to 12 o’clock position, called the “warning” position. This allows for a half-turn to set up the strike.

To make the adjustment of the star wheel there is no need to completely disassemble the movement. Loosen the nuts on the strike side and gently lift the plate taking care not to dislodge the wheels on the time side. Disengage the star wheel from the adjacent wheel and rotate it slightly so that the hammer tail is in the middle of two of the star tips.

_{Tail and star point (arrows), in this photo, the tail is almost resting on the star point which is not the optimal position}

The adjustment was made. On the test stand, the hammer tail isn’t perfectly centered between two of the star points, but it should function adequately.

If the hammer tail is in contact with the star point at the end of the strike sequence, it will hold in the raised position and the strike may not function at all from that point onward. While you are making this adjustment, ensure that the strike lever spring (which is a straight wire) is on the outside of the strike arbour.

In Sum

Adjusting the strike mechanism on an HAC movement requires patience, precision, and attention to detail. By carefully aligning the hammer paddle, star wheel, and other components, you can restore the clock’s striking functionality and ensure reliable performance. While challenges such as this are common when reassembling these movements, a systematic approach and an understanding of the mechanism’s function can make the process smoother.

January 28, 2025 0

Hamburg Amerikanische Uhrenfabrik | Servicing an 8-day Countwheel Strike Movement – Part II

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.

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.

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.

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.

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!

October 1, 2024

Hamburg Amerikanische Uhrenfabrik | Servicing an 8-day Countwheel Strike Movement – Part I

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 crown} _{and 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.

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 sourced} _{and 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.

Mauthe Horse Crown spring barrel in Olie Baker spring winder — _{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.

September 27, 2024

Hamburg Amerikanische Uhrenfabrik: The Clock Company with an Alias

This article traces the historical journey of a significant German clock manufacturer, ultimately absorbed by the Junghans Clock and Watch Company in the late 1920s. After providing a brief overview of its history, the article will delve into the specifics of the clock movement that is next on my workbench.

_{HAC 14 day time and strike, a relative’s clock}

HAC trademark, crossed arrows — _{HAC trademark}

HAU adopted the cross arrows as their trademark in 1892, and it became synonymous with the brand.

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 the production of high-end wristwatches.

Before I embark on servicing a clock from my collection, I make an effort to gather information about the clock’s history. If details about the clock prove elusive, my fallback is to delve into the broader history of the company behind it.

Two Hamburg Amerikanische Uhrenfabrik clocks

The two HAC clocks in my collection are mantel or shelf clocks.

The clock pictured above was acquired several years ago.

It has an earlier version of a HAC production movement because of the solid front and backplates. It is quite possible that this clock was made in or around 1900 or a little later.

_{HAC clock movement with solid front plate}

Now, turning our attention to the second HAC clock in my collection, the one I will be working on next. The clock was acquired about two years ago from a clock collector in Ottawa, Ontario. The previous owner knew nothing about the clock but a plaque on the clock case gives a glimpse into the clock’s history.

This clock is a later production model because of the construction of the plates which I will explain further.

HAC clock number #2, model unknown, a later production — _{HAC clock number #2, model unknown, with a dedication plaque}

While the wheel positions, levers, and movement size remain identical, there exists a noticeable difference between the two clock movements as can be seen by the solid front and back plates on the first clock movement and the various cutouts in the front and the back of the second movement.

_{Open plate, a later production movement}

The use of open plates typically indicates a cost-saving decision made by the company. This choice is often driven by the aim to reduce manufacturing expenses by minimizing the amount of brass used in a movement.

HAC clock #2, #36 movement — _{HAC #2 movement}

Aside from the four brass mounting straps and the slight difference in the positioning of one “V” shaped lever springs, HAC movement #2 has all the characteristics of the #36 movement pictured below.

_{No. 36 HAC time and strike clock movement}

The story of two clocks made at different times in the company’s history is both captivating and compelling.

And finally, who is The Rev. J.H. Cox? A search online reveals nothing at this point.

Before concluding that the clock was manufactured in 1926, it’s important to note that relying solely on plaques for dating may not always be accurate. The clock might have spent time on a retailer’s shelf, or it could have been acquired second-hand, introducing questions as to its actual production date. However, there is a 5,25 number on the upper left of the back plate which might be a date code. HAC was known to have begun dating their movements in the 1920s.

Now, on to servicing the clock movement the details of which will be covered in a forthcoming post.

March 22, 2024

Servicing a HAC Clock Movement

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.

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 on the click is indicated by an arrow — _{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 exposing wheels and levers — _{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.

March 19, 2024

Dating a Hamburg Amerikanische Uhrenfabrik (HAU) shelf clock

During the Christmas season, we split our time between Calgary, Alberta, and Ottawa, Ontario to see our 2 daughters. While in Calgary my wife spotted an interesting item on an Ottawa Facebook Marketplace, an English time and strike clock.

She showed me the photo and I said, “that does not look like any English clock I am familiar with. The style is definitely German”. There is a commemorative plaque on the front base section which references an English church so, I am assuming the seller thought it was English.

When we picked it up from his home outside Ottawa I was surprised to learn that the seller is a clock collector and had no idea the clock he was selling was German. Occasionally I sell clocks to manage my collection and when advertising one for sale I make it a point to know the maker.

But, no matter, it was in very good condition and in working order.

_{The movement showing the single strike rod and pendulum bob}

The maker is HAU or HAC. The familiar cross arrows trademark of the maker is stamped on the movement, in the middle of the backplate.

became their trademark in 1892. In 1926 the company went into a cooperative with Junghans and in 1930 they finally merged with Junghans.

The date on the plaque says 1926. However, HAC/HAU clocks are difficult to date prior to Junghans acquisition of HAC/HAU in 1930. Once Junghans and HAC began their collaboration in 1926 some of the movements were date coded.

Plaques are a good but not foolproof method of dating a clock. A clock purchased as a gift in 1926 could very well have been sitting on the retailer’s shelf for two or more years.

Catalogs are another good but hardly foolproof method of dating a clock. A catalog confirms that a model was made in a particular year, but that same model was probably offered 5 years +/- from the year of the catalog.

I will probably not determine a more reliable date for my new clock than circa 1926. The movement, compared to an earlier model (below), also has many cutouts and additional holes that indicate that it was a late production model and confirms that is closer to the 1926 date.

The clock runs for a while and stops. It is in need of a service but I expected to clean it as many of these old clocks have rarely seen the inside of a clockmakers’ shop.

February 4, 2022

HAC/HAU movement servicing

The arrangement of the gears should be familiar to anyone working on German clocks made in the first quarter of the twentieth century

Bought on an online estate auction site earlier this year, servicing the movement is the subject of this post. Once the movement is serviced, the next step is to address dirt and grime on the case and see what I can do to improve the look of the dial although I am not very hopeful that I can do much to improve it.

For those unfamiliar with the HAC acronym, it stands for Hamburg American Clock Company, a well known German company acquired by Junghans in the late 1920s. It is otherwise known as Hamburg Amerikanische Uhrenfabrik or HAU. Kind of a strange name for a German clock company but that is how the original investors wanted it named.

I have a number of German clocks including familiar makers such as Junghans, Mauthe, Hermle, Jauch, Gufa, and Gustav Becker but this is the first HAC clock in my collection.

Assessment of the movement

It is a typical 14-day German time and count-wheel strike circa 1900 to 1910. It is a robust and almost industrial looking movement and perhaps made early in this series of movements. It could be the type #21 although I can find nothing to confirm it.

The arrangement of the gears should be familiar to anyone working on German clocks made in the first quarter of the twentieth century. This movement has slightly thicker plates, no cutouts, and no extraneous holes and looks sturdy.

It has been worked on in the past, the strike side mainspring having been replaced at some point in the clock’s life. The time side has the HAC cross arrows stamped on the mainspring and appears to be original.

It doesn’t look as though there were issues at the time when the mainspring was replaced, no punch marks around the pivot holes or new bushings, for example, but there are wear issues now and that is to be expected in a 100+ year old clock movement.

In total the movement required 9 bushings, 6 on the strike side and 3 on the time side; 4 on the backplate, and 5 on the front plate. A couple of pivot holes are questionable and exhibit some wear and out of an abundance of caution I bushed them and why not while I have the movement apart. As expected there is more wear on the lower parts of the trains.

The bushing work went as expected. Some of the pivots are quite small and required 2.50mm OD bushings which I don’t often use but have plenty of them in my supply.

Ultrasonic cleaning did not do much to brighten up the brass plates, but to me aesthetics is unimportant. My goal, as always, is simply to have a properly serviced movement that runs well.

Assembly and testing

The movement was assembled and oiled. Both the strike and the time side are running well. There were no particular problems setting up the strike side other than a couple of attempts setting up warning before I got it right.

It continued to run well during the next couple of weeks.

It is a 14-day movement but I find with these German movements that winding them once per week ensures more accurate timekeeping.

April 27, 2021

Strike Adjustment Required

In Sum

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Bushing Work

Reassembly

Testing

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About the Company

Condition of Case and Remarks

The Movement | Notes and First Steps in Servicing

Next Steps

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The arrangement of the gears should be familiar to anyone working on German clocks made in the first quarter of the twentieth century

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