Free download hermle service manual

If the item is damaged in transit, the buyer must file a claim with the carrier. The buyer must also assume all the responsibility for local taxes, duties and airport surcharges if such are added to any shipping costs. We do not ship floor clocks internationally unless you make your own arrangements.

Please carefully inspect your purchase when you receive it. In the unlikely event that the clock needs to be returned due to damage incurred during shipping, please contact us to let us know so that we may issue a return authorization without delay. Please keep all original packaging materials and include these with your return. A damage claim must be made with within 7 days of receipt of the item for us to accept the freight charges for a return of a domestic purchase.

Beyond that period, you will be required to assume responsibility for the freight charges, as per the manufacturer's policy. Manufacturer policy varies slightly when it comes to the "change of heart" items" Hermle's policy on in stock items is that you may return your clock for any reason within the first 30 days, no questions asked.

Please note that restocking fees and shipping fees apply to returns of undamaged items. Please contact us right away if you changed your mind about your purchase. We will be happy to mail you a return label so that you can send the clock in its original packaging back to us. If you want to exchange the clock, we will be happy to assist you with choosing another one and waive the restocking fee as long as the clock is still in original packaging and new condition.

Hermle does not accept returns unless damaged on special order items. In the unlikely case that the item is damaged in transit, the manufacturer reserves the right to replace or repair the item rather than issue a refund. The vast majority of Kieninger and Sternreiter clocks are special order items and therefore can not be returned.

A few of the Kieninger clocks that are available in stock are not eligible for return but in some individual cases, may be eligible for exchange for the same or higher price item. Please keep in mind that the exchange is always at the distributor's discretion but we will do our best to accommodate your needs.

Romba cuckoo clocks available in stock may be exchanged for the same of higher price items. No refunds will be issued as it is against the distributor policy but we will work with you in the unlikely case you may decide that you do not like the clock you initially chose. Please contact us if you have any questions about our return policy.

We are always happy to be of assistance. An exquisite clock is a special, perhaps once-in-a-lifetime, gift. Whether the gift-giving occasion is a wedding, an anniversary, a birthday, a retirement or any other milestone event, we believe our customers should have the opportunity to personalize their special gifts to create a truly lasting memory. These simple but elegant brass plaques measure 1 inch by 3 inches.

Choose up to 3 lines and up to 20 characters per line. Your personalized message is entered in a form that is provided on the merchandise checkout page. The personalized plaque ships in an envelope included with the gift order. It is easy to affix the plaque to either the bottom or back of the clock. Please allow one additional day for processing of orders that include an engraved plaque. We wish you a lovely celebration!

Can not be combined with other gifts and promotions unless otherwise agreed in advanced. Each clock we offer has unique serial number and comes complete with paperwork you need to obtain warranty service. Please follow instructions enclosed. In order to obtain service, please call first to make sure that the repair you need is covered by warranty and to see if the shipping may be covered as well.

If it is the part that is needed, in most cases, the manufacturer is able to ship the part to you free of charge. This is the most extensive and comprehensive warranty in the industry, which of course is to be expected on these hi-end items made with the highest quality of materials and the best workmanship.

Romba, Trenkle Uhren and other brands we offer are covered by a standard 1-year manufacturer warranty. We're pleased to provide our customers with peace of mind that their clock will continue to function properly or be repaired or replaced at no cost.

The Hermle service manual First published in Subjects Catalogs.. Table of Contents Chapter 1 Servicing, repairing, restoring, and replacing Hermle movements. Chapter 2 Hermle mechanical movements, weight, spring movements, chime and strike adjustments, timekeeping adjustments on Hermle movements with a pendulum, timekeeping adjustments on Hermle movements with balance wheels, mainsprings.

Chapter 3 Automatic night shut off, understanding the stopworks. Chapter 4 Cleaning and oiling Hermle movements, with instructions as where to oil each different type of movement. Chapter 5 Obtaining Hermle parts. Chapter 6 Technical information, beats per hour charts, weight charts for different movements, pendulum lengths for different movements, gear train calculations, wheels, pinions, timekeeping, mainspring data. Chapter 7 Bushing and repivioting Hermle movements.

Chapter 8 Hermle movement identification and characteristics, mechanical,quartz. Chapter 9 Service work in the customers home, installation of movements in cases, trouble shooting. Edition Notes Includes index. Classifications Dewey Decimal Class H65 Community Reviews 0 Feedback?

Clock Repair from Daniel James Causey. Loading Related Books. Hovey Paperback in English - 1st ed. Setting the chime shifting mechanism is best done with a familiar melody. Westminster lends itself to doing the initial adjustments as there are clearly defined patterns that can be seen and heard in each measure of music. In setting up the Westminster chime on any movement, it is easiest to identify the down scale run of the first quarter. With this measure having been identi fied, the cam and locking device on the front plate can be synchronized with the pin barrel.

Insure that the train shuts itself off immediately after the last hammer for the measure falls. The screws should be tightened lightly in place at this stage as additional adjustments will probably be necessary. Once the clock movement is capable of executing the Westminster melody correctly; the others can be checked.

Shift the selector to each of the other positions and observe the relation of the pins in the barrel to the hammer tails. Ideally, the pins for the melody selected should be cen tered on the hammer tail lifting surface, Minor adjustments can be made by loosening the screw on the collar that determines the position of the pin barrel. When all of the melodies can be executed with the pins properly engaging the hammer tails in the correct sequence the lateral adjustments can be considered complete.

A final check should be made to insure that none of the unused pins are passing dangerously close to any of the hammer tails. With the lateral adjustments complete, a final check must be made to insure no hammers are left in the air at the end of a measure. It is not uncommon to find that minor adjustments will have to be made to insure each of the hammers drops off at the end of the eight note melodies.

Once this adjustment has been completed a final test run of each cycle should be carried out. The shifting device must be capable of moving freely when the chime train is at rest. There should be no dragging of pins on hammer tails as the pin barrel is shifted at each quarter. It is not unusual to find that minor adjustments need to be made at this point. When the lever is moved, the barrel must be completely free to travel its complete length through all three melodies without interference any place along its path.

Most adjustments on the chime mechanism can be carried out with the movement on the bench. The pattern in which the hammers fall can be observed and the appropriate adjustments applied to achieve the desired results. The final test should be made with the movement in the clock case with the rods or gongs in place. It is a worthwhile investment to purchase a set of rods to use on the test stand if this type of work is done on a regular basis.

It is much easier to make these adjustments while one has unrestricted access to the movement. C Section 5 The Chime Auto Correction System The automatic chime correction system installed on Hermle movements is probably one of the most practical in the world.

It is easy to understand and it is simple to adjust. The chiming system on Hermle clocks is activated by a four lobe cam affixed to the center shaft.

A close examination of this cam will reveal that three lobes are the same height and that one is taller. The cam is designed this way so there is a distinct difference between the hour lobe and the three quarter lobes that precede it. The tallest of these cam lobes plays an active part in the operation of the automatic chime correction system.

The principles the auto correct system operates on are quite simple. When each quarter of the chime melody is aligned in its correct sequence, the train will allow itself to be unlocked by the shorter lobes on the cam affixed to the centersh aft. When the correct sequence is interrupted, a locking device shaped like a hook falls into place and arrests a pin mounted on the locking disk.

This disk is located on the wheel arbor that follows the cam that governs the amount of time the chime train is allowed to run as it identifies the appropriate quarter. Behind this cam is a small drum with a notch that allows the locking hook to drop down immediately after the music for the third quarter has been completed.

Once this locking device is in place it will only respond to the tallest lobe on the cam on the center shaft, allowing the others to pass by without any action. The tallest lobe on the cam on the centershaft will lift the locking device out of the way at the appropriate time to reestablish the correct chiming sequence. This occurs when the minute hand indicates the hour on the dial. Once the correct number of measures of music have been re leased to identify the hour, the chime train will resume its normal operating pattern.

Thereafter, the trainwill allow itself to be unlocked by the appropriate cam lobe on the centershaft. This system operates very reliably. The main causes for its failure are inadvertent adjustments made by well intentioned people who do not understand it, and gummy lubricants.

If the levers in the chiming and striking system cannot operate freely, the auto correct will not be able to lock and unlock reliably. As the shaft supporting these levers encounters very little rotating action, it is best to leave it without lubrication. The collar that holds the shaft in place behind the front plate must have enough sideshake to allow the lever assembly to drop quickly. Quite often gummy lubricants will interfere with the freedom of these components.

As is the case with any system operating on the principle of a hook engaging a pin, the condition of each component and the proper adjustment of the assembly are important. When the pin has been arrested by the hook very little friction should be encountered when lifting it. Check for wear or rough surfaces on the pin or hook if this is not the case. Polish both components if they do not slide smoothly against each other.

Adjustment of the locking device on the auto correction system is not difficult. The auto correc tion system operates on the same cam that shuts off the chime train at the end of each quarter. When the proper adjustments have been made to shut the train off in the correct position the chime auto correction system components will operate as they are supposed to after they have been put in place. Section 6 Hammer Adjustments The sound of a bell, gong or tube can be affected by the manner in which the hammer strikes it.

Hermle movements are constructed in a manner that allows the hammers to be adjusted quickly and easily. To impart a pleasing tone the bell, rod or tube must be struck with a sharp blow and then it must be allowed to vibrate freely without contacting the hammer. Before bending the hammers the complete chiming and striking system should be examined. The damper system or rebound mechanism that brings the hammers to a gentle rest should be operating effectively.

A light coating of grease should be in place between the hammer tail and the damper or rebound mechanism. When it is clear that this mechanism is allowing the hammer to come to rest reliably in the same position each time, the hammer itself can be adjusted. It is not enough to simply bend each hammer so it contacts the bell, rod or gong. The hammer must be able to strike a sharp blow when its tail has been lifted as high as it will go by the lifting device and allowed to fall off.

Once the hammer has struck the gong it should come to rest a suitable distance away from it. Thereafter, there should be no contact between the hammer and the gong until the next time it is lifted and released.

If the hammer does not travel far enough forward to make contact with the gong, the arm should be bent just enough to allow the head to make contact and fall away. The arm must be overstressed enough to actually make an adjustment that will remain in place after the hammers have operated for a respectable amount of time. The arm of the hammer must be bent back away from the gong to relieve this situation. The parking position of the chime hammers can be changed by adjusting the downstop or re bound mechanism.

On chiming movements, rotating the cam forward or backwards will raise or lower the hammers. On striking movements, the damper or rebound mechanism can be bent to regulate where the hammer will come to rest. These mechanisms should always have a light coat of grease between the components that slide against each other. PART C Timekeeping Adjustments A mechanical movement must be in good running order before it can be expected to deliver acceptable timekeeping service.

Excessive friction from any source can have an adverse effect on the timekeeping ability of a clock movement. Therefore, every wheel bearing must be in good condition and every lever that is lifted by the time train must operate as freely as possible.

All of the components that are placed in motion by the time train must be in good running order includ ing the escapement components, the auto beat setting mechanism, the crutch and the pendu lum assembly.

If a clock is to be expected to deliver precision timekeeping performance, the escapement and every component between the escape wheel and the regulating nut on the pendulum bob must have a minimum of free play.

Components that are designed to allow forward and backward movement of the pendulum leader should be able to slide freely, but should not have excessive space between the parts. Rotating parts should move freely, but should not have excessive wear in their pivot holes.

Wear is an enemy of precision timekeeping. If the escape wheel and the pallet arbor have the least amount of wear, the clock movement cannot be expected to run with the maximum vigor. If the crutch yoke has been allowed to operate without grease for an extended period of time excessive wear can take place in this area. The slot should be restored to its original configura tion and closed so there is a minimum amount of free travel between it and the pendulum leader.

Once the movement and all of the components that affect its timekeeping ability have been determined to be in good order, the technician can proceed to regulate it. All Hermle mechanical movements lend themselves to being regulated with electronic timing instruments. The results of these adjustments can be seen immediately. Electronic instruments can save a tremendous amount of time when this work is being accomplished in the repair shop. Section 1 Floor and Wall Clock Escapements Hermle escapements can be expected to deliver several years of reliable service without attention.

If the escapement is kept free of dust and abrasive materials, these mechanisms will run for a considerable amount of time without showing any signs of wear. Most problems with escapements present themselves when accidental damage occurs to the movement or when an unwary person leaves it incorrectly adjusted. By their nature, escapements must have an adequate supply of clean oil to operate properly. As the teeth and pallets slide against each other, degraded performance can be expected if the escape Each face or sliding surface of the pallets should be given a drop of clock oil.

The clock should be operated until the escape wheel has made approximately a quarter turn and then the oiling process should be repeated. The escapement can be considered as being correctly lubricated when the tip of each tooth visibly glistens with a thin, uniform coating of oil.

Once the teeth have been lubricated, a drop of oil should be put on each of the escape wheel and pallet arbor pivots. Traditionally, the relationship between the teeth and the pallets is accomplished with two adjust ments. The first is the adjustment of the entry pallet. This is accomplished by moving the bridge that supports the pallet arbor closer to the escape wheel or by backing it away. The second adjust ment is accomplished by increasing or decreasing the span of the pallets.

This adjustment will influence the relationship between the teeth of the escape wheel and the pallet that will receive the impulse on the inside face.

Hermle floor clock pallets are made from a solid piece of metal to precision specifications. The outside drop can be adjusted by moving the bridge or adjusting tab that supports the pallet arbor. No adjustments should be attempted to alter the span between the pallets. Complete pallet arbor and crutch assemblies are readily available from supply houses selling Hermle parts and it is better to replace these assemblies than attempt to apply adjustments to them.

The escapement is considered to be properly adjusted when an equal drop occurs between the escape wheel teeth as they are in the process of being received by the entry and exit pallets. The drop, or amount of space an escape wheel tooth travels without being in contact with the pallets, can be observed from the back of the movement.

The clock will operate with more vigor when the amount of drop has been reduced to a minimum in the escapement. After this adjustment has been accomplished, the clock can be put in beat.

The care with which the above adjustments are made will affect the vigor with which the clock runs. A poorly adjusted escapement will result in a marginal pendulum swing, unreliable performance and an uneven sounding tick. Placing a Hermle floor clock in beat is easily accomplished with the automatic beat setting mecha nism. When this adjustment has been applied the pallets will stay in contact with the escape wheel for an equal amount of time. Putting the clock beat differs from the previous adjustment in that it does not influence the amount of free travel the escape wheel has before the tooth lands on either of the receiving pallets.

Each time a floor clock has been wound or the case has been opened, it is advisable to swing the pendulum enough to allow the automatic beat setting mechanism to function so the pallets can settle into their proper position.

The purpose of this mechanism is to provide a means for the clock to put itself in beat each time the pendulum is put in motion. Over the years there has been a tremendous amount of confusion concerning auto matic beat setting mechanisms and it is not unusual to receive a movement on which this mecha These attempts range from mutilation of the parts to the application of glue between the moving components.

Automatic beat setting mechanisms are installed on Hermle movements for a good reason the customer can understand how to operate it. In most cases it is impossible for the customer to understand how to adjust a beat setting mechanism that is held by friction or must be bent.

More over, very few customers are willing to pay for repeated service calls just to have an unstable clock put back in beat. The spring tension on Hermie automatic beat mechanisms is set with precision instruments at the factory.

Left alone and properly handled, they will work indefinitely without any maintenance, It must be clearly understood by both the customer and the service technician that: -.

Auto beat mechanisms should never be oiled No attempts should be made to increase the spring tension on auto beat mechanisms Because they contain plastic components the auto beat mechanism should never be placed in cleaning solutions of any kind.

The customer can usually understand how to operate the self beat setting mechanism. They should be instructed to make use of it each time the clock is wound to insure it settles back to an even beat. If the customer insists on leaving a floor clock on an unstable surface such as a thick carpet, they must be instructed to use the auto beat setting mechanism each time the clock is disturbed or sinks deeper in one direction or the other.

By their nature, auto beat setting mechanisms are not perfect, but they do solve more problems than they cause if they are understood by the people in contact with them. Section 3 Timing Hermie Movements When the clock is ready to be put back in operation careful consideration must be given to re establishing its timekeeping ability. Wall and mantle clocks can be timed on the bench, but it is best to make the final timing adjustments on floor clocks in the location where they will be oper ating.

Many customers are reluctant to learn how to adjust the timekeeping rate on a floor clock. They expect it to keep time within a minute or so a week and are often more willing to adjust the minute hand each time they wind the clock instead of applying the required corrections to the pendulum.

In instructing those customers who are willing to regulate their own floor clocks, it is important that they understand that the timekeeping rate is governed by the location of the center of the bob.

If they operate the adjusting mechanism and fail to move the bob, no change in the timekeeping rate will result. If possible, the customer should record exactly how far the bob They can avoid placing fingerprints on the pendulum if they wear cotton gloves when they make these adjustments. When customers are reluctant or incapable of adjusting their own floor clocks it is best to accom plish this service for them.

This can be done quickly and accurately using a portable electronic timing device. Hermle movements lend themselves to being timed with these instruments as the model numbers and other data necessary to identify them are stamped on the back of each movement.

Hermle has supplied the timing data on their movements to the manufacturers of these timers so it can be included in the manuals that accompany these instruments when they are purchased. There are two different types of portable electronic timers on the market today that lend them selves to timing floor clock movements. Although they both deliver excellent results it is impor tant to understand the differences between them. One of these portable timing instruments uses a system that measures the time interval between each tick the timepiece produces.

The time interval between ticks can be electronically averaged to even out differences caused by microscopic irregularities in the escapement.

A figure based on this average will appear on the screen of the instrument. This figure can then be compared to the tables supplied with the instrument. Once the time interval that is known to be correct for the movement being tested has been determined, the appropriate adjustments can be applied to the regulating mechanism on the clock. The clock can also be put in perfect beat with this type instrument.

The second type of timer utilizes a completely different timing system. It electronically computes the number of beats the escapement produces in one hour. The actual sample reading can be taken in about two minutes and this figure can then be compared with the tables supplied with the instrument. When the correct number of beats per hour has been determined, the clock can be regulated so the figure on the screen matches the one known to be required for accurate timekeeping.

Some timers using this principle can be used to put the clock in beat. Both timing systems can be counted on to deliver accurate results. If the regulating nut is not disturbed and there are no appreciable changes in the environment in which the clock is operat ing, it will continue to deliver accurate timekeeping service when the rate has been established using one of these instruments.

Tables to use these instruments for timing Hermle mechanical movements are included on the following pages. Section 4 The Pendulum Assembly The condition of the pendulum plays an important part in the ability of the clock movement to run reliably and deliver good timekeeping service.

This is often overlooked during servicing, repair or restoration work done by uninformed clockmakers. Pendulums are manufactured so their components lock together.

This stabilizes the pendulum and insures it will travel in a predictable arc. If a person with no knowledge of clockmaking has altered these parts the operation of the clock can be adversely affected. The suspension bridge must be secure. If the bridge is not tightly fastened to the movement the clock will probably refuse to run reliably. The suspension springs installed in Hermle movements have no extra space between the slot and the upper block of the suspension spring.

The suspension spring must be free to move backwards and forwards. There should be a slight friction between the slot in the bridge and the top block of the suspension spring. The weight of the pendulum should be able to move the block backwards and forwards. This action is impor tant as it prevents the suspension spring from binding if the clock case settles forward or back wards into a carpet.

The use of pins and wire should be avoided as these have no ability to adjust the amount of space between the slot in the suspension bridge and the top block of the suspension spring.

The pendulum leader should hook securely to the bottom block of the suspension spring. Again, there should be a limited amount of friction between these parts when they are assembled. The pendulum leader should be capable of moving forward and backwards on the pin in the bottom block, but not laterally. The pendulum should hook securely onto the pendulum leader and remain in place. When in stalling the pendulum on a movement that is already mounted in a case, double check with a mirror to insure that the pendulum is properly secured in place and that the hook has seated completely.

Some pendulum bobs are made with a recess in the bob that accommodates a slot cut in the top of the rating nut. The purpose of preparing these parts in this manner is to allow them to lock together.

When the rating nut is moved down, the pendulum follows with it. This insures that the pendulum bob actually moves when the rating nut is turned counterclockwise.

If the rating nut has been separated from the slot the bob is likely to stay in place and the nut will move down the threaded shaft alone. As there is no connection between the components, no change in timekeeping will occur until the bob has been pushed down to meet the rating nut. The pendulum bob must fit the pendulum rod in a suitable manner. A bob affixed to a wooden pendulum rod will normally have a tab that holds the components securely together by spring pressure.

The friction provided by this device should be sufficient to prevent any excess move ment between the bob and the rod. The pendulum bob should be able to slide along the pendu lum rod smoothly but without any excess play. Lyre pendulums must be handled carefully.

If the component parts have not been fastened securely in place the timekeeping ability of the clock can be adversely affected. It is best to handle these pendulums with cotton gloves when removing and installing them. Although the modern balance units are more straight forward and easier to understand, the technician should not shy away from servicing the older assemblies.

Both units can be replaced, although stocks of the old discontinued floating balance units are rapidly be coming depleted. Like movements that are fitted with pendulums, those using balance units must be in good running order before they can be expected to perform to their maximum capability. By their nature, badly maintained pendulum clock movements seem to continue to operate and deliver acceptable timekeeping service.

However, movements with balance units do not seem to be as tolerant. If the movement is not in good running order, there is a good chance the balance unit will not operate with acceptable vigor and the timekeeping rate will be totally unacceptable until the cause of the problem has been dealt with. Timing adjustments should not be attempted on a movement with a balance unit that is operating in a sluggish manner.

If the clock movement cannot sustain the balance unit with acceptable vigor throughout a complete winding cycle, any attempts to regulate it will be futile. Sluggishness in the balance unit is usually caused by excessive friction in the movement or in the balance unit itself. Like any other endeavor, it is best to understand what to expect from a well maintained clock movement fitted with a balance unit. The balance should move with a rhythmic tick when it is correctly in beat.

Beat adjustments can be made by changing the relationship between the arbor that supports the balance wheel and the collet on the inner coil of the hairspring. With the beat adjusted, the balance should make at least a complete turn before it reverses itself.

This action should be accomplished with reasonably good vigor and at the exact frequency required to deliver precise timekeeping service. The tables supplied with most modern electronic timing instruments will show what figure should appear on the display to achieve accurate timekeeping results.

It is prudent to take several readings during a winding cycle as the consistency of the balance rate over an eight day period is a good indicator of the condition of the movement. Section 1 Hermie Balance Units Two balance units are listed in the Hermle Spare Parts Lists and in the catalogs of supply houses that carry these items. BC 19 -. The 80 19 is used on smaller movements such as Model The BC 19 is used on larger movements such as models , , and This makes it extremely easy to order balance units as the BC 19 fits almost every movement in the Hermle inventory except the series.

Hermie balance units operate very much like the conventional escapements found on many antique clocks. The escape wheel teeth lift the pallets. The pallets are affixed to a lever. As the lever comes in contact with a set of pins affixed to the balance wheel an impulse is applied at exactly the right moment.

Once the pallet has done its job of propelling the balance it remains locked in place until the pins on the balance wheel unlock it and the process repeats itself. The major differences between Hermle balance units and conventional escapements of this nature lie in the guard and fork design. The Hermle guard consists of a ring suspended on an arm extending from the balance wheel arbor.

A gap appears in the ring which allows the guard pin on the lever to interact with it. While the balance is traveling to the right, the guard pin remains outside the ring. As the balance travels to the left the guard pin travels inside the ring. This arrangement insures that the fork will always be in position to receive the pins mounted on the balance wheel.

Properly adjusted, the horn on the fork should never touch the ring while the balance is in operation. The rating data for Hermle balance units is stamped on the inside surface of the rear plate. Hermie balance units have banking pins that can be adjusted. These pins serve to protect the pallets from accidental damage as they limit how far the fork can travel.

When the banking pins have been precisely adjusted, they can contribute considerably to the efficiency of the operation of the escapement. These balance units rarely go out of adjustment on their own. If they have fallen into the hands of an unskilled repairman they can be received needing adjustments. This can be checked by stopping the power in the time train and noting where the balance wheel comes to rest on its own. Insure that the hairspring is left in a level state after this adjustment has been accomplished.

Although it is easier, faster and more practical to buy replacement balance units, Hermle bal ances can be disassembled for cleaning and restoration work. Measure and note exactly where the hairspring is pinned. Once the hairspring is free, the top bearing cap can be unscrewed to release the balance wheel. As with other balance units of this type, all traces of cleaning residues must be completely re moved from the bearing surfaces and they should be completely dry before the reassembly and lubrication process begins, A small quantity of good clock oil should be placed on both the top and bottom bearing surfaces before the balance is reassembled.

Tightening the top bearing unit too tightly Approach the tighten ing process very carefully and make a series of small adjustments until the proper amount of endshake results. Unlike the floating balance, rating adjustments are normally made by adding or subtracting weight from the balance wheel. Rating adjustments can be made beyond the range of the regulator by lengthening or shortening the hairspring and repinning it. Of course, this necessitates adjusting the beat to compensate for these adjustments.

From a time saving standpoint it is usually wiser to replace a defective balance unit than to spend several hours regulating it or working with the hairspring. If the balance needs extensive adjustments, chances are it has more than one prob lem and replacing the complete unit is the wiser choice.

Section 2 Floating Balance Units For several years Hermle produced a considerable number of movements with floating balance units.

These movements were well suited for installation in bracket clocks. The floating balance units were very reliable and lent themselves to very respectable timekeeping adjustments.

A tremendous number of clocks with floating balances are still in operation or are mounted on movements requiring servicing for reasons other than because of malfunctions in these units. Because they were not constructed like the traditional balance wheel mounted on an arbor, these units were not completely understood by many clockmakers. They failed to understand that the principles of operation were essentially the same as the traditional balance unit, only the suspension and guard functions were arranged in a slightly different manner.

When a floating balance is in good order, it has the advantage of not having to contend with friction caused by the weight of the balance wheel bearing down on the end of the pivot. There are no arbor pivots on a floating balance that must support the weight of the wheel as there are in a traditional balance system.

The balance wheel is literally suspended by the hairspring. A taunt wire running through jeweled bearings installed in the tube that supports the wheel holds the assembly in its proper place so it can contact the lever that drives it. In most instances the cause of sluggishness in a clock movement equipped with one of these units is excess friction in the train, not in the floating balance itself. The main cause of failure in floating balance units is usually gummy residues and accidental damage.

Many uninformed clockmakers thought they could improve the performance of a sluggish unit by oiling it. As the oil hardened and collected dust, the freedom of the unit was hampered even more. One cardinal rule of working with floating balance units is to understand that the jewels that the guide wire runs through should be clean, dry and free of any abrasive or gummy residues. Cleaning can be accomplished by placing the unit in a good solvent that has the capability of dissolving gummy oil, thoroughly rinsing the bearings and then completely evacuating any re maining liquid likely to turn into gummy residues.

This latter point is important. The solvents used must be chosen carefully. If a fast drying solvent is used it is likely to damage the hairspring. Fast drying solvents cool as the liquid evaporates. The solvent selected must also lend itself to being evacuated from the tube. To insure that all of the solvent is removed from the tube the unit should be upended and a piece of very absorbent paper placed at the junction between the guide wire and the bottom jewel.

This will draw the solvent out of the tube by capillary action as it settles to the bottom of the tube. This process may take several hours and it is advisable to start cleaning the floating balance early in the repair or restoration process so the unit will be completely dry and free of residues when the movement is ready to receive it.

No attempt should be made to fit the balance unit on the movement if there is any evidence of solvent remaining in the tube. New style balance units are readily available and can be substituted for floating balances that are not capable of working correctly. From a production standpoint this is the wisest course of action.

In those cases where the customer desires to keep the original movement intact, it is possible to service floating balance units and restore them to good running order. Section 3 Regulating Floating Balances Floating balance units can be regulated closely enough to satisfy any customer who under stands the limitations of a mechanical clock.

These units were made so customers can regulate their own clocks. However, most people are reluctant to do this job themselves until they have been convinced the task can be accomplished without damaging the balance unit. In most cases, it is better for the service technician to regulate the clock if the customer continues to display reluctance in the matter.

Floating balance units allow themselves to be regulated with electronic timing instruments. Some allowance must be made for differences in the rate at the beginning and end of the winding cycle. After the clock movement has been run for a winding cycle the appropriate adjustments can be applied as a result of estimating the difference between the extremes of the electronic instrument readings.

The Hermle factory has supplied the manufacturers of these instruments with technical information concerning these balance units and the appropriate rates appear in their instruction books. Changing the rate on floating balances is an easy matter providing it is in the range of the regulator.

A clean balance unit in a recently restored movement should respond to the regulator and should not demand unusually large adjustments. Ideally, a restored movement should leave the shop with the regulator set near the middle of its scale.

If this is not practical, it should be adjusted as well as possible. It should not be left resting at either extreme; banked up against the fast or slow regulating stop. Adjusting a balance that runs much too slow can be accomplished by removing a matched pair of weights from the inner or outer rim.

These weights should be directly across from each other so the poise of the balance is not disturbed. Minor adjustments can be made by removing the weights from the inner ring. Conversely, larger rate adjustments can be made by removing a pair of weights from the outer rim.