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When and Why to use C cell clock movements

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When should you consider a C cell clock movement?  The primary reason to use a C cell clock movement is longer battery life. Changing a common battery in your clock every couple of years is usually not a problem. But, when it’s in a hard to reach clock high up on a wall, or inside a case that’s hard to open or access, it can become a solvable problem. These larger C cell batteries simply store more electricity, so they last longer. A C cell movement is larger than a AA battery powered movement. It has to be to hold the larger battery. If you have room for it in your case, you can double the length of time between battery changes, especially if you use fresh Alkaline C cell batteries. We offer standard C cell time only, time and pendulum, time and chime as well a high torque movements. We even offer a continuous sweep high torque C cell movement. We simply have the best C cell movement selection anywhere. When using mini quartz  (AA battery) or standard quartz (C battery) time, or time and pendulum movements, there is a difference between the torque (or turning power) of C cell movements and the smaller AA battery versions. In this case the C cell movements will drive slightly larger hands easily. That’s why we offer optional hands in the 5” to 6” range in gold or black for use with our C cell standard movements. The C cell pendulum movements have a 3-1/2 once capacity, which is more than the AA movements. If you are using hands under 6-1/2” (measured from the center of the mounting hole to the tip), […]

Atomic Clock Movement versus the Auto-Set Movement

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Auto-Set High-Torque battery clock movements have now changed the way we adjust clocks for Daylight Saving Time(DST). For the past decade or so a radio controlled movement, or Atomic clock movements, were the only way to do this. The battery clock movement would receive a radio signal, and either stop or fast forward an hour to adjust for Daylight Saving Time. In theory this was a great idea, because the time broadcast on radio station WWVB is based on the Caesium -131 Atomic Clocks in Fort Collins, Colorado. It’s very accurate and it’s broadcast on a low frequency AM radio wave. Unfortunately, there are a variety of AM broadcast issues which can potentially cause interference with the reception of the atomic clock signal being broadcast. In practice, AM (amplitude modulation) radio waves can achieve long distances. There are potential problems include interference from, power tools, appliances light dimmer switches and especially solar geomagnetic storms, which are quite common.  At their strongest, these storms cause the atmosphere to “light up” in northern and southern regions of earth, producing the northern (and southern) lights. An Auto-Set clock movement does not have the potential problems that an atomic clock movement does. It’s more reliable because it does not depend on receiving a radio signal. Now Auto-Set movements completely eliminate the need to receive a radio signal at all, and still adjust for Daylight Savings Time (DST) twice a year. All of the potential problems with a so called Atomic Clock Movement are gone. We at clockparts.com are proud to introduce our High Torque Auto-Set movements. We have both a US and a World version. They are unique because they will power clock hands up to […]

Getting Your Money’s Worth From AA Battery Clock Movements

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Battery operated clock movements  (or clock mechanisms) are truly a modern marvel. These “little black boxes” can easily last 15 or 20 years with normal indoor use, and they are accurate to within a few minutes a year. Normally they will operate for a couple of years on a good, fresh alkaline battery. The truth is though, that there is a huge difference in quality between a cheap imported movement made in a third world country in  factory with a dirt floor, a one made in a clean modern factory with a robotic production line. No one makes a better battery operated quartz movement than a robot. No human hair, sweat or parts of the employee’s lunch. I am a lucky guy. In the nearly 40 years I have been in the clock parts business I have been able to visit factories all over Europe, Japan and China. Much of what I have seen is very impressive, like the factory I once visited where the quartz crystals used in clock movements and other devices are made. It’s a “white room” operation that has a nearly “medical” level of cleanliness. This particular factory was in Japan and before I could enter I had to put on coveralls that covered by entire body, head and shoes. The latter was a problem because I think they had never seen a size 13 shoe before. After being properly clothed, I had to walk through a decontamination tunnel that removed any dust or contamination that was on my clothing before I could actually enter the factory itself. On the other end of the spectrum I have also been in factories that were unheated with dirt […]

How Auto Set Movements Saves Time in Our Everyday Lives

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Auto set movements have changed the way we adjust clocks for Daylight Saving Time (DST). For the past decade or so radio controlled movements were the best way to do this. The clock movement would receive a radio signal, and either stop or fast forward an hour when needed. In theory this was a great idea because the time broadcast is based on the Caesium -131 Atomic Clocks in Fort Collins, Colorado. The accuracy is the result of the process of radioactive decay. The term decay in this case means “change.”  A radioactive substance naturally changes by emitting particles (protons, neutrons, or electrons) which results in the production of a different element. For example, uranium decays into lead.  Caesium decays into barium. The detection of these particle emissions by a sensor (as in an atomic clock) generates the time signal.  The accuracy of this natural process is not affected by temperature, pressure or any other environmental factors. An atomic clock will work just as well in space as anywhere else.  Atomic clocks are accurate to better than one second over 200 million years. Unfortunately, there are a variety of AM broadcast vulnerabilities which undermine the reception of the atomic clock signal.  Although AM (amplitude modulation) radio can achieve great distances, these vulnerabilities include interference from appliances, power tools, light dimmer switches and (especially) solar geomagnetic storms which are quite common.  At their strongest, they cause the atmosphere to “light up” in northern and southern regions of earth, producing the northern (and southern) lights. Fort Collins, Colorado is a significant distance from many areas in the US, rendering locations in Maine and Florida susceptible to signal interruption. Further issues are the […]

Replacing A Mechanical Movement With A Battery Operated Quartz Movement

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Often times this change has to be made for simple economic reasons; if the old mechanical movement is worn out, the price of a new German made mechanical movement can be very high. Sometimes it’s also just for less work and maintenance. Either way, some considerations have to be made when changing a spring wound or weight driven movement for a battery operated movement. If you think your clock may have any value, keep the original mechanical movement lightly oiled in a plastic bag and store safely. First remove the clock hands. If you have a second hand it will normally just pull off. The minute hand (the longer one) is usually held in place by a small round nut that needs to be unscrewed, or a tapered pin which must be removed. After this minute hand hardware is removed, pull the minute hand off. The hour hand (the shorter one) is normally just pressed on and can be pulled off. Mechanical movements are usually fastened to the clock dial or the back or front of the clock case by four metal “feet”.(see drawing) If you unscrew the nut holding each foot in place you will be able to remove the mechanical movement from the case. Every clock case is different, but these suggestions will work in most situations. Once the old mechanical movement has been removed, you can measure the depth, or dial thickness at the mounting hole. It can either be just a metal clock dial, or a metal clock dial on a 1/8″ – 1/4″ piece of plywood. This thickness will help to determine what shaft length of a battery operated movement would be best. Clock hands […]

Choosing a Replacement Movement – Interactive

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Inevitably it will happen, you’ll have to replace parts for your clock. Batteries die and leak, motors burn out, and sometimes hands can get damaged. But, that’s why we’re here! We can help you find the parts you need, even if you don’t know very much about how your clock works. It’s not too hard, you just have to follow some instructions and take two measurements and answer four questions, that’s it. Just fill in the form by clicking on the link below and we will e-mail you back with suggestions. You compare to make the final decision. Please include all requested information. It’s probably impossible to cross reference any manufacturers part numbers you may see, as you may have already learned. It’s all about finding an equivalent. So let’s figure this out together! Replacement Parts Form

Removing A Battery Operated Clock Movement

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Analog clock movements (with clock hands, not digital) don’t just float in the air; they are always attached to something when they are telling time. It can be a traditional wood or metal clock case, or a novelty case such as a sea shell, mounted photo, tennis racquet or 12″ vinyl record.  Almost anything. Eventually though, they get old and need to be replaced. It’s pretty easy if you follow our simple instructions. To remove the clock movement you will need to remove the clock hands first. If you have a second hand, this will normally pull off. Thin needle nosed pliers can be used to pull upward on the back of the second hand near the hub to remove. The minute hand can either be pressed on the minute hand shaft, or held there by a small round nut (as shown above). If it’s a “press on”, then just pull it off. If there is a small round nut, then hold the minute hand still while turning the small round nut in a counter-clockwise direction until small round nut comes off. Gently pull the minute hand upward to remove. Almost all hour hands are “press on”, so rock hour hand gently while pulling away from the clock movement. Thin needle nosed pliers can also be used under the hour hand at the hub to assist in removing it. Now that the clock hands have been removed, it’s time to get the movement out of whatever clock case it is in. Most battery operated clock movements are installed by a system called “Center Fixation”. Some type of nut is threaded onto an exposed threaded metal shaft, or interior threaded shaft, […]

Pendulum Movements

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Choosing and installing a pendulum movement requires a couple of simple, extra measurements. You need to measure the hand shaft as you normally would. (Link to First Time Clock Repair) you also need to measure the pendulum length by installing the pendulum on the movement, then measuring from the bottom of the pendulum to the center of the clock face. Also note the diameter of the pendulum bob (the round disc). Please see the drawing below: If you are replacing an old mechanical movement with a modern battery operated quartz pendulum movement, please remember that the pendulums for mechanical movements are usually too heavy to be operated by a modern battery operated quartz movement. As long as your pendulum measures 16″ or less, our adjustable pendulums will work on your clock. All you have to do is choose what size pendulum bob (the disc at the bottom of a pendulum) you would like. They are available in 2-1/8″, 2-3/4″ or 3-1/2″ diameters. You choose what’s best for you! If you have pendulum that you want to use, and it weighs more than 2-1/2 ounces, then you should consider this heavy duty pendulum drive for your next project or an even more powerful PHDPD which is our most powerful pendulum drive available. As always, your choice of pendulum movements also includes your choice of over 50 styles of clock hands in gold or black. Just pick what you would like. We stock two lines of time only pendulum movements. Our American made AA battery powered line: And our C cell powered line of pendulum movements: Both lines of pendulum movements can be used for a variety of applications. The “C” cell versions […]

Large Clocks

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If you want to make or repair large clocks, then clockparts.com is the place to be. We sell the best and most powerful high torque clock movements in the business. We have 2 shaft lengths of our American Made AA Battery powered high torque movement and 2 shaft lengths of our imported C battery High torque movement, as well as pendulum and continuous sweep models. The best selection anywhere. All of these models feature our exclusive Extended Minute Hand Shaft. This feature allows an increased space between the hour and minute hand, which is helpful when trying to properly align the 2 hands. We are making it easy! Our high torque movements can run hands as large as 17-3/4”. This will allow you to repair or use with clocks up to 40” in diameter, depending on the layout of the numbers. If you are repairing a large clock, it is general best to order new hands with a high torque movement as the hole sizes in clock hands are not standardized. You can see the clock hand mounting hole sizes at: If they match what you have, then you will be able to use your old clock hands. If using your old hands, please check to make sure that your minute hand (the longer one) is balanced. This is easily done by placing the mounting hole on your fingertip to see if the hand is balanced. If it lays there flat then it’s balanced, if it tilts or falls off, then it’s not balanced. Large minute hands can be balanced by using small amounts of latex caulk on the back. If you would like to wall mount our high torque […]