I have been in Columbia, PA for the last few days. After arriving a day early to do some clock and watch related sight seeing including a visit to Merritt’s Clocks and the NAWCC Museum, class time arrived.

I have been doing clock repair for a while now and feel like I can generally take care of most things wrong with a clock. I have been hoping to get to that level of skill on the watch side as well, as my collecting habit exceeds my financial ability to pay for someone else to service my watches. I received an email announcement about the NAWCC’s Introduction to Pocket Watch Repair class and decided it would be a great opportunity to take some of the fear out of tearing into a watch.

The Introduction to Pocket Watch Repair class is a two-day class that covers removing a watch from its case, disassembling and cleaning it, and then reassembling the watch. Implicit in this I suppose is that the watch is supposed to work when I’m done with it.

I have been pursuing clock repair for several years now and feel reasonably comfortable tearing into time only and time and strike movements. The advantage of these clocks is they’re relatively simple one and two-train clocks, and the parts are largely big enough to see (though pivot polishing benefits from magnification), and large enough to repair or re-fabricate if necessary. Watches on the other hand – even relatively large pocket watches are a different story. Much of the work needs to be done under magnification and parts replacement in the modern era is largely done by scavenging from parts movements sourced on Ebay or antique stores due to the difficulty of creating replacements.

I was under no illusion that a two-day introductory class would make me a watchmaker, but I hoped that a guided walkthrough would be a good first step for someone like me who has some desire to be able to do this but will never have the time to go to watchmaking school.

This class covered disassembly, cleaning, and oiling and reassembling an Elgin 12-size watch. All materials were provided – I just showed up and sat down. 

My victim, er, repair subject was this Elgin 12-size watch.

Elgin 12-size watches were chosen because they are extremely plentiful and inexpensive, and so that everyone in the class would be working on the same movement.

The first day of the class consisted of learning how to use a loupe, tweezers, and screwdrivers, and basic disassembly and reassembly of the watch.

Around lunchtime we had been guided through full disassembly of our watch.

 

The afternoon of the first day covered partial reassembly, again just to get us time on the tools.

I have an Optivisor at home which magnifies for both eyes, however we used a single eye loupe. This took some adjustment – at first closing the other eye, but then learning to keep it open and let it go unfocused. In the end, I grew to understand why watchmakers work this way – the focal distance of your loupe eye is 2 to 3 inches, and the screw you need to pick up is 8 inches away. With only one loupe, you have a close-focusing eye and a normal-focusing eye. The hardest thing for me to adjust to was trying to gauge depth perception with just one eye. I found myself not knowing where my tweezers were relative to what I was trying to move with them. Our instructor told us that adjustment isn’t too difficult and our brain uses cues like shadows to know where things are.

The balance assembly is the most delicate part of the watch, containing the hairspring, the balance, and the balance cock. The balance rotates around the balance staff, the pivots of which are microscopically small and very fragile. Normal disassembly of a watch requires removing the balance assembly, and while doing that, the balance hangs precariously from the stretched-out hairspring.

This picture shows the winding and setting mechanism on the left side, and the gear train. The pallet fork is silver at the bottom of this picture, and has two jewel stones which contact the escape wheel.

The second day of class included disassembling the watch again and cleaning the components in a solvent with a small brush.

The classroom was equipped with a pair of cleaning machines each costing as much as a very nice used car, but thankfully we learned a method that, though it wouldn’t impress a real watchmaker, is reproducible at home.

After cleaning the parts, we re-oiled the appropriate locations and began reassembly. The most difficult part is aligning the pivots into the bridges. A fellow classmate attempted to pound the bridge back on, resulting in our instructor crying “That’s not how you put a watch together!” Thankfully I didn’t have too much trouble. I think many hours of pivot alignment on a larger scale with my clock repair work gave me a sense of the mechanics and I was able to translate it to the watch.

In the end after losing one screw and dislodging one of my pallet stones by being overly aggressive in cleaning the pallet fork, my watch ran approximately as well as it did before I started “fixing” it, which I consider a personal success.

I thought the class was well worth the time and the trip. I’m sorry that I am unavailable for the second part of the class later this year. Hopefully I can catch other classes in the future as time allows.

 

I am in Columbia, PA this weekend taking the Introduction to Pocket Watch Repair course. I arrived a day early to check out some clock and watch-related things in the area. In addition to taking a drive over to Merritt’s, I made sure I left time to go through the NAWCC Clock museum

Lancaster Detour


On the way back from Merritt’s in Pottstown to Columbia, I stopped at the former Hamilton Watch factory building in Lancaster. What a cool building! It’s now filled with condos rather than watchmaking industry, but it’s a neat piece of history, and the tower clock is still there and being maintained.

 

 

The Museum

 

The NAWCC Museum is a beautiful building situated in a residential neighborhood of Columbia. It snuck up on me. I exercised in the morning of my first day in Columbia and ran within a block of the museum but didn’t see it. The museum clock tower stands 50 feet high, but in a neighborhood of churches and civic spires, it seemed a bit camouflaged. It wasn’t hard to find when I was looking for it, though.

The foyer features several tower clocks and a couple interesting tall case clocks, as well as this street clock movement. I have dreamed of owning a tower clock movement. I don’t know if that will ever happen due to their cost and physical size demands, but a clock like this street clock may be a slightly more accessible way to get there.

The NAWCC’s collection exceeds 12,000 items including these tall case clocks and a display of early clockmaking. 

One of the items I found really fascinating was a pantograph engraving machine that carved the designs on watch cases. Nine watch cases would be placed in the body of the machine, each underneath a graver. The template – a large disk of maybe 16 inches in diameter would be placed on the pattern holder and an operator would trace the engravings from the template and the machine would translate that to a smaller scale on the 9 ganged watches. I’m always fascinated by simple mechanical solutions to difficult problems. My day job is in Information Technology. If I were to design something to do this, it would involve computer controlled machinery and huge cost and complexity. This machine is an elegant and simple solution that was reliable and due to the large size of the patterns could be operated by relatively unskilled operators.

There are a huge number of fabulous clocks and watches at the museum; far too many to do justice to in a blog post. One thing I really enjoyed was this display of Hamilton military timepieces. I have a number of these items in my personal collection and seeing them here made me feel a part of the museum. I may never have a clock tower in my yard, but it’s fun to tell guests to our house that this same watch or clock is in the National Watch and Clock Museum. At least it’s fun for me. Maybe the increase in declined dinner invitations from our friends and family should be taken as a hint that a little less clock conversation would be a good idea.

 

In all seriousness, the museum is wonderful. They do a nice job of explaining timekeeping and have a collection that covers many eras of horology, in America and internationally. If you ever find yourself even remotely close to the museum, it’s well worth a visit. If you’re a member of the NAWCC, admission is free.

 

I am in Pennsylvania attending the NAWCC Introduction to Pocket Watch Repair class. I arrived a day early to visit the NAWCC Clock and Watch Museum as well as see some of the local clock businesses. I decided to make the hour-long drive to the Pottstown area to stop in to Merritt’s Antiques and clock supply. Merritt’s is one of the major clock repair material suppliers and has a significant online business. They also have a storefront that customers can visit.

The drive from Columbia where I am staying to Merritt’s is part freeway, part road construction, and part rural maze. Even with GPS, I drove past it once before finding it. To be honest, the outside of the building is pretty…well…dumpy. The good news is that as it was a nice day the door was open and I was greeted by this view, which removed all doubt whether my long drive was worthwhile.

This picture shows maybe 25% of their inventory. It’s hard to count, but there must be 750 clocks and 75 pocket watches. 

The sheer number of clocks is staggering, but Merritt’s has done a nice job organizing and laying them out. There are some concentrations of similar clocks, but you really need to browse the whole place even if you are only interested in a particular type of clock.


I’m always interested to see how prices vary between different dealers. Some dealers are simply delusional. Others seem to have a strange mixture of good values and overpriced items. For example, a dealer I visited in Colorado recently had absolutely astronomical prices on their pretty average clocks – $800 for kitchen clocks and Ogee clocks, however their watch prices were reasonable. For the most part, I thought Merritt’s prices were reasonable. In addition to that, they were having a sale this month, so I walked away with my arms heavier and my wallet considerably lighter and felt good about the value I got. Thankfully I was limited by what I could carry home on an airplane, and so had to leave a number of cool pieces behind.

I enjoyed my interaction with the two employees that patiently helped me as I dug through their watches. We chatted about the softness of antique prices right now and how Merritt’s is still in business because they adapted and chose to sell their inventory at current market prices rather than try to hold on to prices from when the market was higher.

I knew Merritt’s was a valuable source of clock material. I didn’t know they had such a significant retail-friendly clock and watch operation. I have seen many other cool clock and watch related things on my visit to the Columbia area, but this was a highlight. I would encourage you to invest a few hours to take a bit of a drive and visit Merritt’s.

Clocks are most useful when they keep accurate time. While very few mechanical clocks are as accurate as modern quartz movements and certainly will never match the absolute accuracy of your cell phone or computer’s USNO Master Clock-synched time, even fairly low-grade mechanical clocks are more than good enough for regular household use if you take a little time to adjust them.  Check out this article for basic care and operation of your clock.

The rate of a clock is determined mostly by the length of its pendulum.  Several other factors affect the timing of a clock to a smaller degree including the power curve of the clock’s mainspring (fully-wound springs are much stronger than nearly wound-down springs) and environmental factors like temperature and humidity.

It’s relatively straightforward to adjust a clock to correct rate keeping if you have a reference like a cell phone clock to compare against, however this can be very time consuming – especially if you are setting up a new clock that hasn’t been run in a while. You will have to watch the clock over days or weeks to fine-tune its rate. Technology has come to the rescue! The Adams Brown TimeTrax 185 timer is a relatively low cost device that listens to the escapement of the clock and reads the clock’s beat rate on a display. With nearly immediate feedback, you can make repeated rate adjustments and see their effect in minutes rather than days.

How it Works

 

Electronic timing machines like the TimeTrax or the more expensive but more sophisticated Microset use a piezo electric microphone very similar to a guitar pickup to detect the tick/tock of the escapement. The time between the ticks is counted against an internal quartz oscillator and the resulting BPH – beats per hour – is displayed on the screen.

Knowing the beat rate your clock is currently running at is only half the battle. What rate should it run at? That depends on the design of the clock. Large clocks like tall case/grandfather clocks often run at 3600 BPH which correlates to one tick per second. Smaller clocks can’t have a meter-long pendulum and therefore are geared to run at a faster beat rate. This article will help you determine the correct beat rate for your clock.

Setup

 

The TimeTrax’s pickup needs to be clamped onto something metal attached to the movement. For clocks without a center second hand, a winding arbor is generally the easiest place. For clocks with a center second hand, a winding arbor may still be the best place if the second hand is removable. If the center second hand is integral to the operation of the clock as it is on some pinwheel regulators, you will need to find something else to clamp to – a movement post or possibly the dial pan (as an alternative, the Microset timer offers an optical sensor that can be set behind the pendulum).

Using the TimeTrax

 

Once you’ve successfully attached the sensor, turn the TimeTrax on. The TimeTrax includes a beat amplifier that amplifies the sound of the ticks which can be helpful in adjusting the clock to be in beat, but for timing, move the switch to the far right position. After a moment, the device should start counting beats. The red light on the right side of the unit should be flashing with each tick. If the light does not light consistently for each tick or if the light blinks rapidly, the sensitivity needs to be adjusted. Increase sensitivity by turning the gain knob up if the sensor is missing ticks, or turn the gain knob down if the sensor is registering noise as ticks. The sensor is very sensitive to mechanical vibration. Set the TimeTrax down on a stable surface and try not to disturb the sensor cable during measurement.

 

Hit the Beats/Cycle plus key several times to increase the averaging to around 10 beats. The BPH reading should stabilize significantly. 

There is a trade off with averaging. A small sample size means the display updates frequently, however the reading jumps around. A larger sample size means the display more truly reflects the rate of the clock, however this significantly slows the display update rate as the TimeTrax only updates the display twice per sample set. At high sample rates, this means it may take you a minute to get a new reading.

If your clock is running significantly fast or slow, I find that an averaging setting around 10 to 16 beats produces reasonable results with fairly frequent display updates. After I make a couple rounds of pendulum adjustment and get the rate closer to the target, I increase the sample size to around 30 to continue to fine tune.

If you know how many teeth your escape wheel has, setting the sample size to twice the number of teeth on the escape wheel (each tooth is touched twice per revolution – one tick and one tock) will give you the best balance of accuracy and fast display uptime. A sample size different than twice the number of escape wheel teeth will double-count or under-count errors in the escape wheel, whereas a sample size of twice the number of teeth of the escape wheel will correctly average the whole wheel. Many escape wheels turn once per minute – typically larger clocks. For these clocks the number of teeth on the escape wheel is 1/2 of the BPM rate of the clock. For example, a 4800 BPH/80 BPM clock will normally have a 40 tooth escape wheel, so a setting of 80 beats/cycle fully represents the escape wheel. That’s a good place to start, but your clock may be different. Most smaller clocks with beat rates higher than 80 BPM perform more than one rotation per minute, so the above rule doesn’t apply.

Final Rate Adjustment

 

Getting your clock to show its rated BPM on the TimeTrax isn’t quite the whole story. The TimeTrax has a resolution of one beat. That gets you to 99.99% of the correct rate, however the TimeTrax will not tell you if your clock is running at 3600.4 BPM or 3599.5 BPM. Over the course of a week this can accumulate to an error of more than 2 minutes.

There is a second factor that can be significant- the state of wind of your clock when you timed it. While weight-driven clocks always have a constant force and therefore a constant rate as the clock winds down, spring-driven clocks run fast when first wound and gradually slow down near the end of their wind. This error can be a couple of minutes as well. The TimeTrax will get you close, but you will need to fine-tune your clock’s rate over a few weeks by comparing it to an accurate reference like your cell phone clock.

 


 

Balance Function

 

The TimeTrax has a secondary function to help put the clock in beat. To access the balance function, turn the timer on, wait a second for it to initialize, and then press the minus button until the display shows “bal” to indicate it is in balance mode.  

 

The reading will change with every tick of the clock. A perfectly in-beat clock with a perfect escape wheel will display zero for both the tick and the tock. This is not a realistic situation, as every movement has imperfections causing slight errors. A clock that is reasonably in beat will have numbers in the range of +/- 40 or less. If you’re seeing larger numbers, then your clock is not in beat.

Some clocks have imperfections in their escape wheel such that the clock sounds in beat some of the time and out of beat some of the time. Correcting this requires disassembling the clock and working on the escape wheel – either straightening the arbor or straightening the teeth of the escape wheel.

 


 

Putting Your Clock In Beat

 

A clock that is “in beat” will have evenly-spaced ticks and tocks. Clocks that are significantly out of beat will have a galloping sound. Correcting this depends on the type of clock you have.

The first place to start is to make sure your clock is level. Some wall clocks have beat indicators – a scale at the bottom of the pendulum swing. Tilt your clock until the pendulum (stop the clock) point to the center mark of the scale. For mantle or shelf clocks, you may need to shim one side to make the clock level.

If you are lucky, making the clock level will correct the beat issue, however sometimes further adjustment is necessary. Some clocks such as Vienna Regulators have an adjustment near the top of the pendulum – turn the screw to move the pendulum bob relative to the upper pendulum suspension. Make small adjustments and see if the clock is improving. If it is getting worse, turn the nut in the opposite direction.

Some clocks have a verge that is friction-fit onto the shaft so pulling the pendulum slightly farther than its normal travel in the direction of the short tick can help correct the issue. On other clocks, the crutch wire that connects the verge to the pendulum rod needs to be slightly bent. This may require partial disassembly of your clock and is best done by someone with some experience.

If your clock is slightly out of beat, adjusting the clock’s orientation so it is in beat but not level may be a reasonable compromise and won’t harm the clock.  On some clocks that may have lived a bit of a hard life, it might be hard to judge which of the non-parallel sides to use as your level reference anyway.