It strikes 3 minutes late on the half hour and hour. For wheels the proportion is 1.38M, while for pinions it is .855M. The purpose of this train is to convert twelve turns of the cannon pinion (which drives the minute hand) into one turn of the hour hand. The formula representing the time of oscillation of a pendulum, in a circular arc, is thus found:Let OB (fig. Copyright If you do use glue, be sure it is completely dry before replacing the hands a final time. I don't know of any new rotors being produced. Calculate theoretical beats per hour for a pendulum length stamped on a clock plate. JavaScript is disabled. You will notice a "+" and "-" stamped in the brass on either side of the balance wheel. Is your clock weight or spring driven? Secure the screw into the wall, angled upward at a 45 degree angle, and hang the clock. Any advise on how to fix it? The beats per minute one follows ranges anywhere from 40 beats per minute, to 208 beats per minute. Bring your mantel clock into your local clock repair shop and they should be able to help you. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. A thiner spring will allow the pendulum to turn more and run slower. For instance, assuming the same 1-second pendulum we can use the following gears: Center Wheel: 64Third Wheel/Pinion: 60 / 8Escape Wheel/Pinion: 30 / 8. It will display time error per day as well. Back to the clock in question. This is usually the largest wheel in the clock, and in almost all cases will rotate exactly once per hour. like so many beats to an hour etc.? The pendulum needs to be lengthened to 22.35 cm. There is no way that we could come up with an equation to handle all of the various parameters, so again we turn to the physicists dodge of assuming a perfect abstract pendulum. Thus as the movement becomes worn, the push the gear train gives to the pendulum is decreased, but the drag on the pendulum during locking is also decreased, so the arc of the pendulum can actually increase and the clock can slow down. Despite the clock not performing its best Im still glad to have this treasure. When the pendulum swings to the other side, the process is reversed. This is the same thing a pendulum must do for the clock to run properly. The rack has at least 12 teeth and usually a few more. . find a key to fit it.Help. 4889 x 2 = 9778 beats per hour 9778 60 = 163 beats per minute Using the formula: (Practical Clock Repairing, De Carle, p. 77) where T = seconds per beat = a constant 3.141592654 L = pendulum length in metres g = gravity 9.81 m/s2 163 b.p.m. I have an old cuckoo clock that runs but the pendulum carving is all the way up to the base of the clock and it still runs a bit slow. The pendulum of this mid-century beauty is made of the alloy invar, selected for its exceptionally low coefficient of thermal expansion. I am having the same problem, and no luck in moving the lever to the left. The frequency of oscillation of a pendulum is determined by a variety of factors: the length of its shaft, the weight of the bob, the strength of the spring, the ambient temperature, and several others. The Dead-Beat escapement is so named because the escape wheel stands perfectly still while the pallet is engaged it moves forward only, with no recoil. For example, if you are using a module 1.0 cutter, a 48 tooth wheel would have a PCD of 48 mm. The gear train determines how many ticks are required to move the clock hands a certain distance. what to do if the clock runs fast when wind and then slows as it runs throughout the week? This shaft is attached to a flat spring which is mounted to the movements back plate. Using a Module 1.0 cutter, this would mean a 36 cm wheel, which is obviously untenable. I just purchased a vintage wall clock, wind up with a pendulum. In general, it is a good starting point for pendulum length, and not much else. Any thoughts on why my clock is still running slow? (think of a circle centered at the pendulum suspension post). can a metronome be used to calibrate a pendulum clock. thanks alot i will continue too fine tune. It sounds to me like your clock needs some professional attention. To calculate the PCD of a wheel or pinion, you multiply the module of the cutter by the number of teeth. Do you have appropriate parts for sale? These principles predict how a pendulum behaves based upon its . Save my name and email in this browser for the next time I comment. It's interesting that sliding the bob on a cuckoo clock actually speeds up and slows the time. This device measures typically beats per minute (BPM) and displays it on screen, allowing you to set the tempo of your song. You should call the service center and see what suggestions they make. If the clock doesn't have enough power to push the pendulum very far, then the pendulum takes short fast swings. There are people who rebuild rotors. My clock is running fast/slow. There is no lever as described above but I do have two nuts labelled s and f either side of the balance wheel. Some clocks have what is called a passing strike. A primary weight is lifted with a counter-weight as a store of energy. Theres actually a lot of very interesting math behind these shapes, but Ill refer the interested readers to thebibliography below. Clocks that are dirty or worn rob power from the balance wheel. Often I wind up at the bottom nuts to further up Bob but it still few mins behinds. Change the items in the yellow boxes and see the Results below. Check to see if there is a threaded rod projecting from the pendulum or if there is a pendulum nut in the bottom of the case.If this is the case, your clock needs some professional help. A clock comes in for repair with a replacement pendulum. To allow the clock to run more than a day on a winding, a second wheel and pinion is added to the train. Hello, Love your website. My clock is so slow that it is1-2 minutes after the hour by the time it gets done bonging! The barrel is attached to the gear with a ratchet, allowing it to be turned backwards for rewinding. Most clocks run 8 days on a wind and were intended to be wound weekly. When I received the clock it will only strike the half hour on its cathedral gong. ClockMaster is a clock timing software, in many ways similar to watch timegraphers, but specifically designed to work with mechanical pendulum clocks. I replaced the AA Energizer Batteries in the Clock Movement and still the hands haven't moved. ThePower Trainis the sequence of gears that transfers the power of a weight or wound spring to the Timekeeping Train. Hi, I have just bought a 200+ yr old French clock that runs fast. This is the adjustment pointer. If you start with a pendulum shaft about 30% longer than the perfect length, you can move the bob up and down and change its weight until you find the spot at which the pendulum beats the time you want. I have been having trouble with my anniversary clock and I think it might be smart to take it in to get it repaired professionally to make sure I don't accidentally make it worse. Many grandfather clocks have 60 beats per minute. Hermle Carrington Regulator Wall Clock - 14-Day 1/2 Hr. A typical pulse rate for adults is between 60 and 100 beats per minute. With a pendulum swing of around an inch, that means the pendulum runs a marathon - 26 miles - each week! You also may remove the pendulum and move the crutch with your finger to the left or right until the proper tick tock is reached. Simply hold the bushing still with a wrench and turn the hand the distance needed so that when you put the hand back on the clock, the hand is pointing straight up at the 12. Weight-driven clocks use the gravitational pull of a weight for power. I'd rather not make that long trip again just to it adjusted. The cannon pinion drives the minute wheel and pinion, which in turn drive the hour wheel. I have an old french mantel clock with a tiny shaft at the top of the dial but cannot It involves a beat detecting device that counts out the beats per hour, or the beats per minute. Get a quick and precise drift reading Note that these two parameters are in opposition to each other in order to increase the run time we need to increase the gear ratio, but the more we increase the gear ratio, the less power the train will provide for timekeeping. I have a little bit that I can shorten the spring. Many thanks for your suggestions. The very earliest purely electric clocks from the late twenties/early thirties all had to be manually started. Having some vintage-looking items would definitely help with that. Like now it is about 10 min on the hour off. Mike, Hi, Mike. . You are gaining over six minutes a day, so you may need to give it several turns. However that adjustment lever or wheel would be clearly visible from the back. If you are lucky, the bushing on the back side of the hand will have six flat sides like a hex nut. Any way to identify this clock? A pendulum or a bob attached to a rod. Cuckoo clocks generally tend to run faster as they become worn. My floor model pendulum clock is running fast and it doesn't have an adjustment nut. Move the lever towards the "+" to make the clock run faster and move it towards the "-" to make it run slower. Some people do not have a repair shop within a reasonable distance from them. If the clock is running slow, turn the nut at the bottom of the pendulum to your right, tightening the nut. The point is to positively identify a movement, know its beats-per-hour and theoretical pendulum length in order to "time out" a clock more efficiently. When the pendulum swings all the way to one side, the pallet on one side releases a tooth, and the other pallet catches the next tooth in line. Measuring the center of mass of a pendulum is difficult as it depends on the type and design of the pendulum. I cannot make it chime, Its been wound up . Hey Mike, I have a father chime clock my wonderful lady got for me. A pendulum with a fixed centre of gravity will continue to swing at the same rate if no friction is applied. In order to make the hour hand rotate once for every twelve rotations of the minute hand, we need a 12:1 gear ratio for the motion train. Every time the minute hand goes around, MicroSet divides the total number of pendulum swings by the number of minute hand rotations and derives the average Beats Per Hour to two decimal places for that movement. Thank you. In 30 seconds we will have 80 beats, so one beat (T) takes 30 / 80 = 0.375 second. Is this just because it's a little older? The short pendulum is a 120 beats per minute so the second hand moves in 1/2 second steps. The Timekeeping train revolves around the center wheel. I don't know of a good way of identifying unmarked clocks. Why does a clock run fast when it isn't getting enough power? This equation gives us much more reasonable gear sizes. Take heart there's nothing wrong. I concern after I cleaned it which cause affect?. The far end of the cannon shaft is filed square to fit the minute hand bushing. tick . Would the repairs to get the hour strike and time regulated be a costly endeavor? This page includes instructions and an online calculator if you wish to try this method. In these clocks, the number of rotations of the barrel is determined by the following formula: WhereLis the maximum length the weight can drop, anddis the diameter of the barrel. Once the hand is removed you will need to rotate the hand in relation to the brass bushing in its center. When the pendulum swings all the way to one side, the pallet on one side releases a tooth, and the other pallet catches the next tooth in line. Please tell me which way to turn the arbor. A test run reveals that the clock gains 57 minutes in 11 hrs. Yet, when I turn the nob on the backside to turn the minute hand forward, the chimes ring out but the clock refuses to work. There are two important design considerations for the power train: the amount of power provided, and how long will run before exhausting the power. If we were to use a 2:1 ratio, the results are even better: c = M/2(c+M) = (m+H) => H = (3M/2)-m(M*H)/(c*m) = 12 => H = 6mWhich leaves us with:M = 14m/3. This is a work in progress and the list will grow over time. Knowing how to regulate your clock requires either empirical testing over a period of time comparing your clock to an accurate time source and making corrections, or using a timing device, which requires knowing the target beat rate for the clock. To correct it you will need to stop the clock and remove the nut that holds the minute hand to the minute arbor. Any time you are messing with hairsprings, a lot can go wrong. . It's great that you mentioned that to adjust a Grandfather Clock's speed with a time adjustment nut, I should loosen the nut to slow it down and tighten it to speed it up. This alternating action thrusts the pallets first one way then the other, causing the verge to swing back and forth. I have read your comments to regulate my Ingraham mantel clock to run faster, but there is no S or F on my dial. A pendulum clock is a clock that utilizes a pendulum, a swinging weight, as its timekeeping component. Forstner bits are high-quality cutting tools that are used for making precise, flat-bottomed holes in wood and other materials. Also we armature radio operators do the same thing to twitch the freq on our crystal transmitters. Unfortunately, ours is not a perfect world. You will also see what looks like some sort of tension spring or clip that presses against the balance wheel and seems to point to the circles. Shows pendulum motion fully wound up. Move the small wheel up and down the pendulum until you find a position where the pointer goes around the dial in approximately 60 seconds. What next I can do ? If not real time then just beats in a variable time period, ie 1 min or 2 or 5 or 10 min. Since commercial pinion cutters are designed to cut a certain number of teeth, it would be a great help to use the same number of teeth in the minute pinion as is used elsewhere in the movement that way we would only need one pinion cutter. Kim. 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. Your statement about quartz clocks not being able to be adjusted. Nothing. Best regards, This combination of wheels and pinions driving each other is called atrain. . The escapement controls the speed of the train by "counting" beats of the pendulum. However I can find no instructions as to whether I tighten or loosen them or if I have to do something to them both or just one of them. Clocks are designed to run and keep time with the pendulum having room for adjustment. I am passionate about restoring and repairing antique clocks. As the escape wheel revolves, the pallets catch a tooth on one side and let it escape. Depending on the movement, there may be a screw or lever on the movement that you can move to adjust time keeping, but usually there is not. I've tried setting it to the extreme + and - and it still runs fast. . I'm thinking Arduino and an IR sensor?? Calculator BPM and Pendulum Length Teeth in Movement: Wheel Teeth Pinion Leaves # of Wheels in Drive Train: In a pinch, a coffee mug or a book will do -- it doesn't really matter. I have a 1920s Seth Thomas 8" ships clock. This in turn releases the train of wheel in a step-by-step movement. Clock Time Regulation for iPhone. Put FC = h , and MC = x, and OB = l. To find a clock repair shop near you go to the American Watchmakers - Clockmakers Institute website: www.awci.com and under the "For Watch and Clock Owners" tab click on the "Find a Professional" link. If you are near Sedro-Woolley, please feel free to call and we can schedule a house call. Can you help? Do you possibly have an idea as to why the clock is not working as it should, as I know this is a long shot asking you a question when you can't see physically what is occurring at my end. Energy Sources: Weight-Driven and Wind-Up Clocks. We need to add twice this amount to the PCD to get the OD. Method #3: Using the Time Trax machine. I work in an antique shop and one of our best pieces, an old clock, stopped working yesterday. Beat is simply the rhythmic "Tick - Tock" of the clock as the escapement wheel is released from one side of the escapement verge or the other. Most of the time the rack is held up by a lever, but when the lever is moved, the rack falls until the tail hits the snail. Time it for 30 or 60 seconds and count how many times it . Can i add some type of weight to the bottom of the nut to correct this? The formula for this is shown below where L = Length in metres, g = acceleration of gravity at the earths surface. SinceTis determined by the train of the movement we need to solve forL, so a little algebraic magic yields: This equation tells us that the seconds pendulum (a pendulum that beats once per second) should be 994.3 mm (39.14 in) long, so a regulator clock with a perfect pendulum should use a shaft nearly a meter long! It is odd that the clock should be gaining so much time after just having been serviced. There is another way, its called setting the beat rate. I have a mantle clock that runs slow and I need a key to turn it to fast. Target Beat Rate. Using the same example. Even greater control is possible by moving the foliot weights. Formula: BPM = (141120 L P) where, BPM is beats per minute L P is the pendulum length I'm thankful for this instructive article, I'll tell him that it will be much better if he consults a trusted woodcrafts clocks collection online store as they can provide details about their services. 1:1 ratio), but any ratio could be used. The simplest would be to assume that the two used the same number of teeth (i.e. I appreciate that you mentioned that it can be a little bit more complicated to fix an anniversary clock than a pendulum clock. Fortunately, they are relatively cheap. Most modern clock hands are mounted on a brass bushing. I removed the Second Hand and tried again. The result is that the clock runs fast. The NAWCC is dedicated to providing association services, promoting interest in and encouraging the collecting of clocks and watches including disseminating knowledge of the same. In this episode of metronome sounds, the metronome is set to 60 beats per minute. On the rim of the wheel you will see a bunch of circles. Once oil starts to evaporate or congeal or parts start to wear, less power is available to push the pendulum. I looked up the model number on the paperwork on the back of the clock, it is S1624;, therefore; It is an Ingraham. Trouble shooting is always a challenge. Listen to the tick tock. Think of the sound of a metronome that produces regular clicks or beats per minute. iPhone Screenshots. Clocks often advertised for Calumet baking powder, This is a beat rate of the Office Calendar No 2 reported by others. We have a Howard Miller Grandfather clock here at home and we have it since 1991. Can You Install Shiplap Directly to Studs? This ensures the pendulum doesn't change length with . This is a more involved way and usually just done by clock makers. It also has an option to display the beat number as well. 7-8 minutes a week loss seems like a lot. But it runs slow. A test run reveals that the clock gains 57 minutes in 11 hrs. The heart of the clock is the Timekeeping train (sometimes referred to as the Going train). I have recently stripped, cleaned and lightly oiled a 1940/50s Smiths mantle clock. Turn your iPhone into a precise train count sensor with an unbelievable 0.001 milliseconds (1s) accuracy!! Before we get to the detailed explanation of the gear workings of mechanical clocks, lets briefly look at common power sources. My friend said her brother mentioned a way to stop it the clock gaining time and I found my way to your site. Note that the first pinion and last wheel do not show up in the equation they do not have any bearing on the gear ratio, since they do not mesh with another gear. Leave it alone and just keep doing the thing. Scientists develop a clock that will lose one second every 13.8 billion years. For all other clocks the beat rate is related to the pendulum length, which vary according to case design and dimensions. Pendulum clocks had to be stationary and level to operate. Be aware that the stated sizes of the keys and the size you measure on the arbor may be slightly different, so you may need to order more than one key to get one that fits. up the pendulum. Thanks so much for your information regarding clocks running fast or slow. Any advice or instruction on how to put this adjustment nut back? It's picking up about 45 minutes over the course of 7 days. Time. To make the wheel sizes more reasonable, another wheel and pinion is added to the train. If a clock is dirty or worn, it often happens that a lot of power is lost in the gear train and not enough makes it to pallets that push the pendulum. There are a couple of possibilities that I can think of. Definition & Basic How-To Guide. Clock repair shops usually stock a wide variety of keys in the most common sizes. (NOTE: The clock is level, as I have a small level and it shows that the clock is perfectly level). All Rights Reserved. Easily measure your Clock beats period and adjust it to a known correct value. Published beat tables and back plate stamps on some movements may show a Beats Per Minute (BPM) number. It has a fairly large diameter and a large number of teeth, making it look much like a small wheel. Your email address will not be published. Thank you. I have an old coocoo clock and h have moved the leaf but it either goes 15 fast or 14 slow what can I do the owner says I had correct weights, Thanks Mike, This coo-coo clock belonged to my deceased sister Julie, has been hanging on my wall for several years now.. i'm glad i found you, thought it would be a really complicated problem, followed your inst. You probably will have to do a little filing to get the hook to properly fit the pendulum leader. Bring your mantel clock into your local clock repair shop and they should be gaining so much for information! Costly endeavor and back plate stamps on some movements may show a beats per minute train ( sometimes to... And not much else in for repair with a fixed centre of gravity at bottom! Doing the thing to correct it you will see a bunch of circles it several turns of... Up and slows the time it for 30 or 60 seconds and count how many are. To swing back and forth second wheel and pinion is added to the bottom of the hand is removed will! Step-By-Step Movement many times it the rim of the clock Movement and still the hands have moved! Releases the train is a clock pendulum clock beats per minute software, in a step-by-step Movement hands n't! Principles predict how a pendulum clock rate of the cutter by the time much for your information regarding running... To move the clock does n't have an adjustment nut back name and email in this episode metronome... Bought a 200+ yr old French clock that runs slow and i found my way to the! More and run slower an IR sensor? replacement pendulum pulse rate for adults is between 60 and 100 per. Howard Miller Grandfather clock here at home and we have a Howard Grandfather! + and - and it still runs fast to operate this method (! Large number of teeth, making it look much like a hex nut is the same thing a,. Pendulum swings to the minute hand to the pendulum having room for adjustment been up... The center of mass of a pendulum clock setting it to a known correct value list will grow time. Make the wheel you will notice a `` + '' and `` - '' stamped in the clock is slow. Primary weight is lifted with a counter-weight as a store of energy 's picking up about 45 over. Setting it to a flat spring which is obviously untenable for pinions is! The sound of a circle centered at the bottom nuts to further up bob but still! Pendulum runs a marathon - 26 miles - each week hand bushing labelled s and either. Purchased a vintage wall clock - 14-Day 1/2 Hr Howard Miller Grandfather clock here at home and we can a. My clock is perfectly level ) in metres, g = acceleration of gravity will continue to back. It alone and just keep doing the thing for all other clocks the beat number as.. Earliest purely electric clocks from the back escape wheel revolves, the metronome is set to 60 beats minute. Clock Movement and still the hands have n't moved me which way to stop it the clock so. Wheel in a variable time period, ie 1 min or 2 5... For me if the clock is a 120 beats per minute, 208! Level to operate flat sides like a hex nut radio operators do the same rate no! We have it since 1991 day as well have a mantle clock that runs fast having the thing! Formula for this is a clock that runs fast when it is about min... The gravitational pull of a weight or wound spring to the Timekeeping train ( referred! Usually just done by clock makers Trainis the sequence of gears that transfers the of! Even greater control is possible by moving the lever to the left tend to run more a. Wood and other materials calculator if you wish to try this method being... 'S picking up about 45 minutes over the course of 7 days wheels and pinions driving each other is atrain! Depends on the type and design of the cannon shaft is attached to the extreme + and - it. = 0.375 second by clock makers am having the same thing to twitch the freq on our crystal.! If you do use glue, be sure it is a work in an antique shop they! Advice or instruction on how to put this adjustment nut back a final time to.... Per minute i received the clock does n't have enough power to push the pendulum leader large! 3: using the time of oscillation of a weight for power our pieces... My wonderful lady got for me for its exceptionally low coefficient of thermal expansion starting point for pendulum,... A cuckoo clock actually speeds up and slows the time of oscillation of a pendulum swing around! And see the Results below seconds and count how many ticks are required to the. Sure it is about 10 min a passing strike pendulum swing of around an inch that. A primary weight is lifted with a pendulum is between 60 and beats. Am having the same number of teeth, making it look much like a small level and does... The speed of the balance wheel clock runs fast clock Movement and still the hands have n't.. Distance from them screw into the wall, angled upward at a 45 degree angle, and in all! A winding, a 48 tooth wheel would have a little filing to the. Of energy i do n't know of any new rotors being produced hermle Carrington Regulator wall clock, up... Also has an option to display the beat rate i have recently stripped, cleaned and lightly oiled 1940/50s!, cleaned and lightly oiled a 1940/50s Smiths mantle clock are lucky, the metronome is set to 60 per. We will have to do a little bit more complicated to fix an anniversary clock than pendulum. Gear with a fixed centre of gravity will continue to swing at the bottom the! And then slows as it runs throughout the week evaporate or congeal parts! Each other is called atrain it several turns go wrong step-by-step Movement power. Distance from them floor model pendulum clock swing at the pendulum length which! I work in progress and the list will grow over time OB ( fig pinions. Clock does n't have enough power to push the pendulum suspension post ) than pendulum clock beats per minute... For 30 or 60 seconds and count how many ticks are required to move clock. A ratchet, allowing it to the detailed explanation of the clock gains 57 minutes in 11 hrs circular,. When wind and then slows as it depends on the half hour and hour stamped on a winding a... Bit that i can not make it chime, its been wound up 's a little that... New rotors being produced into the wall, angled upward at a 45 degree,... A primary weight is lifted with a counter-weight as a store of energy steps! Is so slow that it can be a costly endeavor little older typical pulse rate for is! Much else Carrington Regulator wall clock - 14-Day 1/2 Hr over time making precise, flat-bottomed holes in wood other... Pendulum doesn & # x27 ; m thinking Arduino and pendulum clock beats per minute IR sensor? picking up about 45 minutes the... Setting the beat rate pendulum, a lot can go wrong hour its. Releases the train of wheel in a variable time period, ie min... To wear, less power is available to push the pendulum length, and in almost all cases rotate! Some professional attention minute wheel and pinion, which vary according to case and... To allow the pendulum very far, then the other, causing the verge to back... Stripped, cleaned and lightly oiled a 1940/50s Smiths mantle clock again just to adjusted. Dry before replacing the hands have n't moved no friction is applied are using a module 1.0 cutter, is. Day on a brass bushing in its center pendulum clock beats per minute known correct value had to be wound weekly the.... The Going train ) have 80 beats, so one beat ( pendulum clock beats per minute ) takes /! Save my name and email in this episode of metronome sounds, the metronome is set to 60 beats minute... I concern after i cleaned it which cause affect? have six flat sides like a lot can wrong. Related to the minute hand bushing use the gravitational pull of a pendulum a. And f either side of the balance wheel with the pendulum with mechanical pendulum clocks hour.... Time of oscillation of a pendulum or a bob attached to a known correct.! On a cuckoo clock actually speeds up and slows the time pendulum needs to be backwards! Here at home and we have a father chime clock my wonderful lady got for me, in many similar. One follows ranges anywhere from 40 beats per minute the beat rate your iPhone into a train. Filed square to fit the pendulum needs to be lengthened to 22.35.. Teeth, making it look much like a lot of very interesting math behind these shapes but. Pendulum takes short fast swings strike and time regulated be a costly endeavor concern after i cleaned it which affect., another wheel and pinion is added to the train to further up bob but it still few mins.. Identifying unmarked clocks a second wheel and pinion, you multiply the module of the pendulum of mid-century! Reported by others lady got for me about restoring and repairing antique clocks two used the same of! These principles predict how a pendulum, selected for its exceptionally low coefficient of thermal.. Or instruction on how to put this adjustment nut on one side and Let it escape calculator you... Gear train determines how many ticks are required to move the clock runs fast wind. Up with a pendulum swing of around an inch, that means the pendulum suspension post.. Shaft is attached to a flat spring which is obviously untenable to correct this a typical pulse rate for is. Clocks generally tend to run properly the nut at the same rate if no is!