Please view these information tabs to help with determining the proper Mechanical Clock Pendulums for your clock.
Types of Clock Pendulums
After knowing who made the clock, it is time to decide what pendulum style is best. Clock pendulums can be divided into three basic categories. Very short mantle clock pendulums will use a mantle bob and these are not discussed in this section. If you have a short mantle clock please search for a mantle bob instead. What is covered here are the types of clock pendulums available for shelf, wall and floor clocks.
- The brass rod style pendulum for small shelf or wall clocks.
- Wood stick pendulums that are used on everything.
A metal Lyre style pendulum are used for floor clocks, in other words for grandfather and sometimes grandmother clocks. We offer these for German post WW2 units such as Urgos, Kieninger, Jauch and Hermle units. These are the only post WW2 German units made, despite the fact it may something other than these names, as the movements were made for various other companies who was able to get there name on the movements instead of who really made them. The Lyre types of clock pendulums are for more of a modern look, if your looking for an antique look instead, please consider the wood stick style as an alternative.
The wood stick will come unstained. This is so the stick can be stained the proper color to match the clock case. The wood stick pendulum consists of the stick with the hardware and also the bob in the diameter chosen. The good thing about wood stick pendulums is they can be shortened if needed.
The brass rod types of clock pendulums are usually used on shelf clocks or wall clocks. Sometimes they are used in grand daughter or grand mother clocks, but this is typically not the situation. These cost more for two reasons, there made of brass and also they are custom cut to size by us here at Clockworks. We will cut it to the exact length you need for your specific clock movement upon your ordering.
Hermle Clock Pendulum Measuring
Hermle Clock Pendulum Measuring is done in combination of the CM number and the pendulum bob diameter. The CM will only be accurate to the pendulum length if the pendulum bob is small. If it has a larger bob it will be a longer pendulum. The larger the bob, or the heavier the pendulum, the longer it needs to be. Best to email [email protected] if you need the exact info on how long your pendulum should be. We would need the CM number off the back plate, and also how wide the pendulum bob is (round disk at the bottom of the pendulum).
The pendulum length (**cm) will be from the suspension post all the way down to the bottom of the pendulum nut threads. The length includes the pendulum from tip to tip, the leader it hangs on, and the suspension spring. This pendulum length will not always be exactly what is marked on the movement. There are other factors such as the pendulum bob diameter. The larger the pendulum bob diameter then the longer the pendulum length despite the CM length.
If the CM length on the old unit matches the CM length on the new unit, this is all that is needed. Sometimes it is required to use the old leader and put it on the new unit. If both CM numbers match and there is still a timing issue, it may had the wrong pendulum. The next question would be, did the clock ever keep time with the pendulum it had?
Mechanical Clock Pendulum Installation
Mechanical Clock Pendulum Installation is done by these steps. Just an interesting point first, typically pendulum makers are not movement makers and these two things are married together by a person or place such as Clockworks.com instead of the movement manufacturer. This is interesting because it explains why there can be so many variants of pendulums available for one movement. Options for the material the pendulum is made of such as a brass rod, wood stick, or metal lyre style as far as what its made out of. Then you have what bob diameter to get for the clock case so it both looks good and at the same time no t wack the sides of the case. The length of the pendulum has to be close to time range length dictated by the movements internal gearing, the top hook has to be in a way to hook up to the movements pendulum leader also. Why is all this mentioned? Because sometimes an old pendulum will not hook to the new movement the same way as it did in the past and you may or may not need a new top hook for the pendulum. Also mentioned so it is clear that any old pendulum will not just work in the clock unless your really just that lucky. The pendulum and the movement sort of need to be married by me or you to get the right one.
If the new pendulum leader is not installed, you will need to put the pendulum leader onto its suspension spring and hang it on the back of the clock. This is done by removing the set screw on the top of the suspension spring. With this set screw out, you can lower the suspension spring and hook on the leader hook to the bottom of the suspension spring and bring it back up to original position. Reinstall the set screw and then Hang the pendulum onto its pendulum leader.
These are the steps at this point
- 1. Make it run, by putting in beat
- 2. Install the hands
- 3. Adjust the chime hammers
- 4. Make it chime
- 5. Set the hands to time
- 6. Make it strike
The mechanical clock pendulum length
A pendulum clock without a pendulum is a shame for sure. Getting the correct pendulum does take some diving into the clock world. If you have no idea what pendulum it would take, this is a basic guide. This is a guide to narrow down to the best pendulum for your clock. This will cover most situations, without special equipment to figure out the length.
On back plate of the clock movement usually there are some numbers and or letters for identification. There maybe an indication of how long the pendulum should be in the mix of these numbers. It may say CM or PL and this stands for centimeters or pendulum length. This would be the length where it should keep approximate time. However this is measured in a few different ways usually dependent on country of origin.
German made movements
The mechanical German made clock movements are easy to figure out the pendulum length. The numbers will let us know or the clearly indicated CM or PL number will be stamped. If it is German, keep in mind the CM length is not the actual pendulum length. Usually the Germans measure this length from the top of the clock movement, and this includes the three components of the pendulum all in one length in centimeters. This length will include the pendulum itself, the leader that it hooks to, and the suspension spring on the top that the leader hooks on to, all in one CM measurement. CM stands for centimeters and PL stands for pendulum length.
If the CM stamp is not on the mechanical movement, any numbers can tell us the pendulum length automatically. If the movement was made post WW2 in Germany like most modern floor clocks, the numbers will tell us. Even though it does not say something like 114CM or just 116 on the movement, the numbers that are there can do the trick such as UW32/1. We know its German made by Urgos, we can go to the Urgos page and see what the PL is. It can get confusing to people who do not care about all this and just want the pendulum. If it gets to be too much, please email us at [email protected] and include a pic or the movement numbers. We will have an answer and hopefully a product.
German grandfather movements
Almost all grandfather clock movements are usually going to be German if its made after 1950. The first thing we need to do is get the numbers off of the back plate of the movement. This is the only way, and we cant cheat by looking at the paperwork or clock case. It has to come right off the back of the clockworks. The manual and the sticker on the case is of no use to get the pendulum.
The American mechanical clock movement manufacturers referred the pendulum length as a "drop". The drop is the length of the pendulum from the hand shaft all the way down to the bottom of the pendulum rating nut threads. It is a different way of measuring the pendulum length from the German made units. Both ways are based on the smallest bob diameter. If the bob is larger or heavier, the length would be longer than what is stamped.
If everything fails for one reason or another, the best chance for a pendulum is the wood stick style. This is the only style of pendulum that can be easily modified because you can chop it. These types of clocks are usually antiques, or of Asian origin, and information such as pendulum length is just simply not available. Sometimes it takes a good guess on where the manufacturer intended to have the bob sit.
To do it this way, you only need a pendulum with a stick that is way too long to begin with. Chop it try it, chop it try it. Each time your slow, cut an inch and half off of the sticks length and hang it back on. It will only take a couple of times and if you start way too long you can always go shorter.
Clock makers method
There is another way, its called setting the beat rate. This is a more involved way and usually just done by clock makers. It involves a beat detecting device that counts out the beats per hour, or the beats per minute. To do this you would need to know what the beat rate is supposed to be for that particular movement first, and then keep adjusting the pendulum length till you have it keep time. There are cell phone aps out there these days that will tell you the beat rate and the cell phone will listen and tell you if the clock will keep time with that pendulum. You go longer or shorter until your phone says the beat rate is set. I have never used these so I cant say much about them, except the app is cheap and people seem to like them. We use the machine here so we never got into the cell phone app yet.
Timing a mechanical pendulum clock
Timing the clock is all about the overall pendulum length and rarely has anything to do with the movement itself. Mechanical clock is easy to time providing you have the correct pendulum. When the pendulum is correct for that particular movement it will hang on the leader and keep approximate time. The fine timing can be done only with the pendulum adjustment located at the very bottom. At the bottom of the bob is some adjustment threads and a nut. To turn the nut one way raises the bob and the other lowers it. A shorter pendulum will make the clock run faster. A longer pendulum makes the clock run slower.
Fine timing the clock
If the clock is timing slow, raise the pendulum bob by turning the nut at the bottom of the bob. If the clock is fast, do the same but raise the clock's pendulum bob instead. One full turn is somewhere around 1-2 minutes a day faster or slower.
If there is no more adjustment
If the bob is all the way up and its still too slow or fast, you can shorten either the pendulum or the leader it hangs on to correct.
A lyre pendulum that does not keep time with the bob all the way adjusted will need its length altered. The overall length can be altered by the pendulum itself or the leader it hangs onto. The leader is about 5 to 7 inches long and engages with the crutch on back of the movement. The leader is the part that the pendulum top hooks on to. It is possible to shorten or lengthen the pendulum leader to put the clock in time range with some solder if needed. 1 3/4 inches is a good measurement to make one of these longer or shorter as needed, as this is the length of the threads at the bottom of the bob. So it will give you a full timing adjustment range all over again and you can go up or down as needed.
German pendulum length CM stamp
The pendulum length is considered overall and not just the pendulum. For example if the clock says 94cm on the back of it, this is the way the Germans measure there pendulum lengths from the top of the movement and all the way down. This will include the suspension spring way up top, the pendulum leader or guide you can call it, and also the pendulum from tip to tip all with a 4 1/2 inch bob diameter. Of course the larger the bob, the longer it will be beyond that 94cm measurement.
Used to keep time, now does not
If the clock kept time in the past but now does not, it means a worn gear. The escape wheel is worn and it is advancing more than one tooth at a time. The escape wheel alone would be hard to find, and hard to replace both. The entire movement would be disassembled to replace this worn escape wheel if there is another one found that will work. The cost of having this done would be the same price as a new movement. There is no such thing as having a repair on a clock movement being better than a new movement. The price would be about the same for a complete overhaul or a brand new one. First see if the clock movement is in production and available new. We do this by getting the numbers off of the back plate of the movement itself, right off of the brass. The email address is [email protected] and we will check availability and quote for the new one. If the movement is not in production anymore, then a repair is the only option.
Mechanical Pendulum Clock Timing Issues - Conclusion
Fine timing of the clock is easy as you can see. If the clock kept time in the past and now too fast, its time for a new movement and has nothing to do with the pendulum. A worn escape wheel is most likely the cause and a new unit would be less cost then a repair.
Urgos Lyre Pendulum Availability
Urgos Lyre Pendulum Availability is none at all actually. They have not been made in over 30 years, in fact none of the outer component have been. However there is still a solution and we can provide the lyre pendulum to you custom fit.
Custom pendulum work
We can customize a new Lyre pendulum for your UW Urgos clock movement here at clockworks. What we do is take a Hermle Lyre pendulum that is still in production, and solder a new top hook to the pendulum. We make the pendulum length special for your specific clock. This solder or riveted on top hook, maybe noticeable but when hanging on the clock no one will see it.
Urgos custom lyre timing
Please understand that we will do our best to create the pendulum length perfect. There is a chance that the pendulum would need to be shortened or made longer beyond the adjustment of the threads. There are times the pendulum length misses its mark. We would need the leader if this happens to make it longer or shorter. The leader is the short bar the pendulum hangs on, that is about 5 inches long.
Upon ordering the pendulum
When you order the custom lyre pendulum, you will get an email asking you the movement numbers. There are two styles of pendulum mounting top hooks. We would need to know only if the movement starts with UW32 or UW03 in the numbers.
The below Mechanical Clock Pendulums are for German post WW2 clocks. The four clock movement manufacturers are listed below. If you do not know who made your clock movement, but it says made in Germany, please see the below number examples. If the numbers are similar to what is below, that is who made the clock movement. This is important to know who made the movement, because then we can provide the correct pendulum that will hook up and keep time. After you know who made your clock movement, its time to decide if you would like a metal lyre style pendulum, wood stick or the brass rod style for wall / mantle clock only.