If you have a Seth Thomas clock that chimes, there is a chance that it is one of their "Sonora" models. These can be distinguished by looking inside of the clock. You will see what looks to be not one, but TWO clock mechanisms within your clock. In reality, one movement (behind the dial) controls the clock and the hour strike. The other movement (near the back of the clock) controls the chime that plays on the quarter hours.
It's an ingenious design. With the addition of the independent chiming mechanism, this system allowed Seth Thomas to reuse simple striking clock movements and sell them as chiming clocks. The down side? If the chime gets out-of-sync with what the hands say, this model of clock has no means to correct itself. That job is up to you. Here's how it is done.
There are two levers coming out of the back of the main clock movement (the one located behind the clock dial). The upper lever (A) will trigger the the hour strike. The lower lever (B) will trip the quarter chime.
If your clock is striking the wrong hour, momentarily press down on the upper lever (A) to trigger the strike. Repeat until the clock has reached the desired hour. If you need to correct the chime too, you might want to stop at the hour before the one desired (see below).
If your clock is striking the wrong part of the chime tune, lift up and drop the lower lever (B) to trigger the chime. It should play 4 notes at quarter past, 8 notes at the half hour, 12 notes at quarter of, and 16 notes on the hour. Once it has finished playing the full chime on the hour, this mechanism will then push on the strike lever (A) one time on its own to trigger the strike. The two mechanisms are playing tag with each other. On the hour, the clock tells the chime to mechanism to start. The chime mechanism plays, then finishes up by telling the main mechanism to strike.
Often, it is convenient to move the hands to the top of the hour (allowing the clock to chime at each quarter), then go about correcting the chime, allowing it to play the full 16 note tune. Finally, advance the strike using the upper lever until your reach right number of blows for the hour shown on the dial.
The inner workings of most clocks are made of brass. As such, clockmakers and repairers develop an a lot of knowledge about how to work with this wonderful yellow metal -- an alloy of copper and zinc. In this regard, we use many of the tools and techniques used by jewelers. A third group that often uses brass are model engineers.
I've written a series of three articles for a well-known kinetic art organization in the UK called Cabaret Mechanical Theatre. The first article in the series showed how to cut brass tubing, rod, bar, and sheet. The second article showed some tools and methods to bend brass. My most recent article describes how to solder brass parts together.
The techniques shown in the articles are commonly employed in my workshop. I hope you enjoy the articles and perhaps find them useful.
I often get phone calls asking if I do house calls for grandfather clocks. The callers often sound reluctant to ask -- like they fully expect the answer to be "no". I can understand this. In many fields, house calls are a thing of the past.
Customers are pleasantly surprised when I tell then them that not only will I do house calls, but it's required for grandfather clocks. So, why is this? Let's take a look at the process for having a grandfather clock repaired.
Step 1: I speak with you about your clock
First, I speak with you on the phone, via email, or in person. Here is my contact information. I try to learn what I can about the clock. Photographs are always helpful. Here are the kinds of things I like to know:
Step 2: First house call to evaluate the clock
Next, I travel to take a look your clock in person. If the clock has been serviced very recently by a professional, there is some chance it can be made to work with some adjustments. This doesn't happen very much. More often, the clock hasn't been serviced in a long time and needs to be overhauled. A clock that stops running after a few minutes, has a slow chime, or other strange behavior is a likely candidate for an overhaul. How can we know for sure? I will often be able to show you the back of the clock movement with the old, black, dirt-filled oil around the pivots and in the cut pinions. This dirt and the associated wear is more than enough to stop a clock. Shall we fix it? On to the next step...
Step 3: Overhaul the movement or (sometimes) replace the movement
I take the mechanical parts out of the clock case and bring them to my shop. These parts include the movement, pendulum, weights, and dial. I overhaul the movement in my shop where the proper tools and equipment are located. Once everything has been reassembled, the clock is placed on a specially designed test stand and allowed to run for a week or more to be sure that everything is working as it should. Certain modern grandfather clocks have movements that are still being manufactured. It can be wiser and more economical to replace this type of movement rather than overhaul the old one. I will be sure to let you know if this option is available.
Step 4: Second house call to Install the movement and configure the clock
Finally, we arrange a time for the clock to be set up. I bring the mechanical parts back and reinstall them in the case. This involves mounting everything properly, and making adjustments that can only be made when the movement is in the case. An example would be adjusting the hammers that hit the chime rods and putting the clock "in beat" with an electronic meter.
That's it! With a couple of house calls and a few weeks, your grandfather clock could be working once again. If you have questions or would like to schedule an appointment you can use the contact form on this site to get in touch with me. Whether you contact me or not, I hope this information has been helpful.
-Dug North, Clock Repairer
I am thrilled to have been profiled in the most recent print edition of MAKE Magazine (Volume 40), which is available at newsstands now. I was asked by the Editor-in-Chief how I made the transition to clock repair as a career and what I like most about my occupation.
Here is an excerpt in which I explain why repairing antique clocks is different from most repair-based occupations:
When you visit your car mechanic, you may or may not be there by choice. Sometimes you simply must get your car running again. It’s not the same with clock repair. Customers have definitely made a choice to have their clock fixed. They have a complicated, delicate machine that they treasure for whatever reason. Perhaps it’s clever, perhaps it’s beautiful, or perhaps it belonged to a grandmother. Perhaps all three things are true. It’s an honor to be entrusted with these heirlooms and gratifying to see a customer’s face when they hear their clock chime for the first time in years.
Here is where you can read the complete article online: From Cubicle to Clock Repair: How I took the leap to following my passions.
When working on an antique clock, it's always best to leave as much of it in original condition as possible. But, to what degree should we take this -- especially when dealing with antiques that were produced in the thousands, even millions? Many clocks are not national treasures, but important family heirlooms. Their chances of being used, appreciated, and passed to the next generation are better if they are attractive and fully functional. Here's an example:
A customer asked to have the paper dial on her Ingraham cabinet clock restored so that the numbers could be read. The photograph shows the result of my work. Is the clock "all original"? No. Is it destined for the Smithsonian? No. Does it look correct and show respect to its original maker's vision? I think so, yes.
For some addition thoughts on the subject, check out Bob Frishman's article on Originality, Restoration and Refinishing. You will need to scroll to bottom of the page to find the article.
People that work with clocks have their own language. When found in a clock, we call the larger gears (or cogs) wheels. We call the smaller gears that mesh with wheels pinions. There is more than one type of pinion, but a form commonly found in American-made clocks is the lantern pinion.
The lantern pinion gets its name from its resemblance to an old-fashioned lantern, if viewed while holding it upright. The lantern pinion was easy to make compared to one cut from a solid piece of brass. This is why it was widely used by so many Connecticut clock manufacturers such as Seth Thomas, Ansonia, Gilbert, Ingraham, Jerome, New Haven, Welch, Waterbury, and Sessions.
The lantern pinion is made up of two disc end caps, usually brass, connected by a series of small steel bars. The end caps are called shrouds and the bars are called trundles. Over time, the trundles can become worn by the teeth of the mating wheel rubbing against them -- usually with a mix of oil and dirt between them. With enough wear, the teeth on the mating gear can get jammed against the worn spots on the trundles. This can effect the reliability of a clock and even cause it to stop. At this point, I usually rebuild the pinion by installing new trundles. That's what the lantern pinion shown above needs. This one is connected to the fan in a cuckoo clock, which helps to regulate how quickly the bird figure performs its action. This is being done as part of a comprehensive overhaul of the clock am am doing for a customer.
The repair procedure involves removing each trundle (often not all at once to maintain the distance between the shrouds), cutting new trundles from hardened steel on the watchmaker's lathe, installing the new trundles, and locking them in place. A worn lantern pinion can be the cause of very mysterious intermittent clock problems. Based on what I've seen, many repairers leave them alone, assuming the trundles will work for another few years. This assumption is probably true, until...one day, it's not.
Here is a video I shot of an unusual "Chime Strike mechanism I just repaired for a customer. The unit is called a "Chime Strike" . The mechanism came out of a Gilbert Hall Clock dating to around 1904.
It's a funny hybrid system. A sequence of chords take the place of a simple strike on a gong or a bell. The sequence will pick up wherever it left off, so the psuedo-song varies from hour to hour. The company called it a "chime strike" which seems appropriate; it's more than a simple strike, but not exactly a tune (chime) either.
I think the chords make a pleasing tone and a very interesting strike.
One of my favorite clock auctions happens in April. I attended the R.O. Schmitt auction in Manchester, New Hampshire on the 26th and 27th. I acquired four new clocks to restore and sell. Here is the first of four that I picked up.
This clock was made in France around 1880 for the American retailer listed on the dial -- Henry Semkem of Washington. The clock case is black slate, the front with patinated bronze panels showing soldiers on horseback in low-relief. It's a dramatic scene to be sure; some of the soldiers are carrying severed heads on pikes! My research leads me to believe the panels show one of the battles that took place as Christians tried to reconquer on Iberian Peninsula.
The dial features a patinated bezel with beveled glass, a black slate dial with Roman numerals, and gilt hands. It is an 8-day movement (meaning you wind it once each week). It strikes the hours on a gong.
This gem needs to be overhauled. The task will be a pleasure because the movement is by a well-known French maker. Once completed, this clock will be for sale. Come check it out at my studio or drop me a line using the contact form if you would like to acquire it. This is a truly unique piece: high quality with many stand-out features and rich with history.
One of the things I love about working on clocks are the tools. They are all so venerable, arcane, specific, and numerous. While you can get away with a modest toolkit, there truly is a tool for every task in this trade. These lifting bars are an example.
On striking clocks that use a rack and snail system to keep track of how many hours to strike, there is a little part called a gathering pallet (shown below). The piece rotates as the clock strikes. With every revolution, the pin sticking out catches a tooth on the saw-toothed rack and moves it up by one increment. It continues to do this until the end of the rack is reached and it often helps to lock the mechanism at that point. If you want to read up on striking clocks, I recommend Striking Clock Repair Guide by Steven G. Conover.
The gathering pallet is on the outside of the clock plates on the end of a post that sticks up through them. It is typically pressed on. It can be difficult to remove because it needs to be on its post securely or the clock will strike endlessly. The gathering pallet must be pried off the post. Sometimes, if the post is sturdy enough, you can use a precision gear puller tool, like the ones shown at right. This is a delicate procedure, because the post is often thin and brittle. If it's too thin, or the gathering pallet too big or awkward for these pullers, a different approach is needed.
You can try using two flat head screwdrivers, but it's crucial the the force be applied directly upward on the gathering pallet. Otherwise, you will stain the post, and possibly break it. This isn't easy with to do with screwdrivers. I made the custom pry bars shown above to aid in the process.
To make these, I found two small flat-head screwdrivers of roughly the same size and removed the plastic handles. I found used ones at a yard sale, but they were something like these screwdrivers. I annealed them with a propane torch. I then bent them to shape and refined them on a stationary belt sander. Once I had the shape where I wanted it, I hardened them. Finally, I cleaned them up a bit with emery sticks so they wouldn't mar the clock plates on which they rest.
Sure, you can buy lifting an prying bars for this purpose, but this was more fun and I got just what I wanted.
Dug North repairs antique clocks in and around Lowell, Massachusetts. He's also known for his mechanical wooden sculptures.