Wag on a wall – servicing a well engineered movement

This wall clock was gifted to me in the spring of 2022. I have no idea who made the clock, there are no markings on the case or the movement. It was likely sold by the Forestville Clock Company of Toronto in the 1960s and my guess, a Hermle movement. I could find nothing else about it online. I wrote an article in August with first impressions.

The style of the clock is a “wag on the wall”. It is a strange name but basically describes what it looks like it is doing, wagging its tail. A Wag on a wall clock is a clock with the movement enclosed in a small case with a pendulum and weights exposed.

From 1660 to about 1870, the wag-on-the-wall was a very common clock style. It is so named because the pendulum appears to wag on the wall like a dog’s tail. It is also a derivative of the English lantern clock (more closely to a converted one with a pendulum). It was eventually deemed not attractive enough to hang on the wall in many upscale homes, so wooden or glass and wooden cases were added. The long-case or grandfather clock evolved from this early wags-on-the-wall. Wooden cases were used to hide the unsightly weights and cast-iron pendulum.

The style did not disappear as many manufacturers continued making the wag-on-a-wall style clock to this day.

There were several clock assemblers operating in Canada up to the mid-1970s, and it was likely imported and assembled by the Forestville Clock Company of Toronto.

It is a rack and snail movement possibly made by Hermle. The second wheel teeth are larger than one would expect so, a lot of thought went into the design of this movement. I have worked on similar movements in the past though this one is a bit different, specifically the arrangement of the hammer assembly, one main wheel is the reverse of the other, and of course, it is a weight-driven time and strike clock.

Based on my initial observations the movement looks fairly clean despite the tarnished brass but I am expecting minor wear issues commensurate with a 60-year-old mechanical clock.

Disassembly

I took a number of photos prior to disassembly. This is my regular practice and although I have worked on many similar movements though there are always minor intricacies that differ from manufacturer to manufacturer.

To remove the movement from its case, two slotted screws holding the movement to the seat board are released plus, the weight chains must be pulled out. To release the chains the weight hooks must be removed.

The rack and snail assembly, minute wheel, hammer assembly, escapement, and pendulum leader were removed initially and placed in a collection tray. What remained were the wheels and the lifting lever between the plates secured by four pillar nuts.

The gathering pallet arbour and the main arbour are pressure fit. So, when I separated the plates most of the wheels fell out, of course. It can be a challenge for first-time clock repairers but when one works on a few there is a certain logic to the placement and orientation of the wheels.

Assessment of the movement

Because there was generally little wear, I made three decisions. I elected not to separate the central arbour and did not pull the gathering pallet from its arbour. As a result, the plate with two arbours attached was placed in the ultrasonic. I did not disassemble the main wheels which were held together with pressure washers. The main wheel ratchets and chain teeth are in very good condition and the ratchet assembly worked as it should and there was no need to take them apart.

I cleaned up residual oil and dirt around the pivot holes, removed excess oil from the pates, inspected the pivots for wear, and placed all parts in the ultrasonic cleaner. Since I was using a smaller machine than my regular US cleaner, the parts were cleaned in three batches which took a little longer.

_{Older, less efficient ultrasonic cleaner}

I took special care drying the main wheels assemblies and ensured they were operating correctly after they were completely free of any moisture

My wife’s hair dryer came in handy but after cleaning and drying all the parts it fell off the table and broke. Sigh!

The pivots, which are in very good condition, are polished, the pivot holes pegged out and the next step is bushing work. Two bushings are required, the second wheel front plate and the centre wheel, back plate. There is minor wear on those two holes but why not address them while the movement is apart.

Reassembly

As with many rack and snail movements, most adjustments are made after the wheels are installed within the plates but three minor adjustments make the job easier and that is ensuring the gathering pallet is free of the rack, the stop wheel is in the 12 o’clock position and the hammer actuators are free of the star wheel. They must be between the star tips, if not, one of the hammers will catch on a star tip and stall the strike.

Testing

Once fully assembled the next step is installing the chains, weights, pendulum, and testing/adjustment. A small adjustment to the height of the pallets was made after which the clock ran well and continued to run well after 5 days. It is keeping very good time, as expected of a weight-driven movement as any clock that is powered by weights releases its power uniformly through its rated cycle.

Yes, it is a very plain-looking clock that reflects the style of the time (the 1960s) but it might grow on me.

September 5, 2022

Wag on a wall clock – does it wag?

My wife’s uncle was an internist (internal medicine specialist) in Newfoundland and practiced for many years but dementia and its attendant complications finally got the best of him. He spent the last 5 or so years in a locked ward of a residential facility for the elderly.

As part of his practice, he set up a home office where he would receive patients and consult with colleagues. In his office was a wall clock given to him by a former patient.

When he passed away his possessions were distributed among his family members with the clock going to his brother who, himself passed away this past year. Unfortunately, there was not much interest in the clock and it spent 15+ years in a Rubbermaid container in the basement of his brother’s home.

His wife is currently in the process of moving to a smaller home, giving away what she could and since I have a keen interest in antique and vintage clocks she determined that the best place for the clock was in the hands of someone who could have it working once again. I did not have a clear idea of what she was giving me though I knew that it was a mechanical wall clock.

^{Quickly mounted on the wall to check things out}

The style of the clock is a “wag on the wall”. It is a strange name but basically, it is a clock with the movement enclosed in a small case and with a pendulum and weights exposed.

In the years between 1660 and 1870, the wag-on-the-wall was a very common clock. It is so named because the pendulum appears to wag on the wall like a dog’s tail. It was eventually deemed not attractive enough to hang on the wall in many upscale homes, so wooden or glass and wooden cases were added. The long-case or grandfather clock actually evolved from early wags-on-the-wall clocks. Wooden cases were used to hide the unsightly weights and cast-iron pendulum.

The style did not totally disappear as many manufacturers continued making the wag-on-a-wall style clock to this day.

There are no maker’s marks on the dial or the movement but it appears to have a Canadian connection. There were several clock assemblers operating in Canada up to the mid-1970s, and it was likely assembled by the Forestville Clock Company of Toronto from parts sourced from West Germany but I will learn more as I continue my research.

The only markings on the movement are a serial or production number ending with 65 behind the pendulum leader and UW 7/29 (a date or other measurement) just above the aforementioned number. The year 1965 seems about right judging from the two-tone case tinting popular in the 1960s, The clock case is not particularly attractive today but such was the style at the time. I don’t think it will ever be my favorite wall clock.

It is a weight-driven rack and snail time and strike movement possibly made by Hermle, Mauthe or Urgos. I have worked on similar movements in the past though this one is a bit different, specifically the arrangement of the hammer assembly and the main wheels are reversed from each other.

_{The weights and pendulum are polished}

It is not apparent upon first inspection if the movement has ever been serviced. Rather than run the risk of further wear I plan to test it briefly before servicing the movement. The movement looks robust and well made but I am expecting minor wear issues commensurate with age when I open it up.

While it is largely intact the bottom middle finial is missing. Otherwise, the case is in very good condition for its age. I mounted it on the wall to check things out and yes, it does wag!

In an upcoming article, I will go over the steps in servicing this movement.

August 22, 2022

Calibrating a typical American spring-driven mechanical clock

In our quest to have our antique mechanical clocks run accurately the immediate response is to regulate the clock, but have you thought about calibrating your mechanical clock? It is not as difficult as it sounds.

This is not the same as regulating your clock. A properly regulated Anerican-made spring-driven clock will show the correct time at the beginning of the week but will run fast through the week and may gain as much as 3 or 4 minutes mid-week and lose time at the end of the week.

Seth Thomas round top — Seth Thomas spring driven round top 8-day clock

Let’s use a spring-driven mantel clock with an 8-day cycle for our example.

Mainsprings release their peak power at the beginning of their cycle. As the mainspring winds down power is gradually released until the spring unwinds completely and the clock stops.

On some antique clocks, one might find “stop works” (otherwise called a Geneva stop) which is a clever star-shaped brass add-on to the main wheel that reduces the full release of power initially by flattening the mainspring’s power curve over its rated cycle (8-days) and thus maintain some level of accuracy through the week.

Geneva stops as indicated by the white arrows

But most clocks I have come across don’t have this ingenious device.

Weight-driven clocks are a different kettle of fish because the release of power is constant throughout the week. Once a weight-driven clock is regulated it should not require calibration.

Gustav Becker Vienna Regulator with weights

Calibration makes the assumption that your spring-driven clock will never accurately tell the time at any one given point in its cycle and essentially means setting your clock so that it loses no more than a couple of minutes at any given time through the week.

Sessions mainsprings, one for the time train and the other for the strike train

According to the Canadian Oxford dictionary to calibrate means “to correlate readings of an instrument with a standard”. If the standard is plus or minus two minutes per week, without the use of “stops” or other means to flatten the power curve, setting the clock two minutes slow at the beginning of the week will ensure that it is never off by more than a minute or two through the week.

According to noted horologist Robert H. Croswell, “If the clock is regulated such that it has a zero net gain or loss of time from the start to the end of the week, then take ½ the maximum fast error during the week and set the clock that many minutes “slow” when the clock is wound.” If the maximum is 6 minutes, then, half would be three minutes.

One could use a complex mathematical formula to determine the precise amount of time to set the clock at the beginning of the week but setting it two minutes slow for a clock that loses 4 minutes each week should suffice for most purposes.

August 15, 2022

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