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Rebuilding whippens

Recently much has been said about the proper definition of a rebuilt piano. The older parts do not have to be replaced but must come up to the standards set by the manufacturer for the new part. I would like to concentrate on one part frequently replaced by rebuilders - the whippen. There are several reasons that I have not to replace parts but to rebuild them instead.


First, there is the convenience of not having to adapt parts possibly not made for the particular piano or that are not the same quality or size as the originals. Secondly, because of excessive action noise caused by teflon - I simply refuse to install Teflon bushed whippens into an old Steinway. Even if no definite clicks are present, there is still detectable noise in teflon whippens.

 

The ultimate product of a note played on a properly pinned, bushed and regulated piano is simply a bell-like tone escaping from the instrument with no evidence of mechanical means; and this can be more closely achieved with a cloth-bushed whippen.

 

Prior to regulation, a properly restored whippen saves on regulation and troubleshooting time, with no action noises to track down.

 

Lastly, the intrinsic value of the instrument, which may not be an antique now, but may be in 50 years has to be considered. Basically, antique collectors see the most value in a piece that has never been refinished or changed by a later craftsman. The highest prices paid for an antique of any sort are those for pieces in original condition. This has to be tempered of course by the function of an instrument. We want a piano to be playable with the least amount of change in the original design so that future generations will have examples of late 19th and early 20th Century instruments as close to the original as possible.

 

The first step is to space the hammers to the strings. This will insure that after removal whippens can be replaced accurately. Number all whippens upon removal. In many cases you will be replacing screws with a slightly larger one for a tight fit, but if you plan to save them keep them in order.

 

Usually an initial dusting off is required just forclose examination of the part. This can be done prior to removal with an air compressor of after removal with a soft paint brush by hand. I use three-sided action trays with a row of numbered screw holes in the back for easy transportation of parts around the shop. Remove all felt and cloth that you have determined has to be disposed of for reasons of wear, moth holes, etc. Clean the spring slot with a toothpick or other wooden scraping tool and regraphite with a No. 3 pencil. Examine the spring to determine if it is too severely bent or corroded to use. New springs are available from supply houses. Remove the centre pin first if one exists (some only have the cloth bushing) and ream the hole.

 

The new spring should be threaded on the bushing cloth as it passes through the hole in the wood. Usually the springs can be cleaned with either very fine steel wool or metal cleaner. Use of the metal cleaner (Noxon) avoids any possibility of scratching the surface of the spring that rides in the slot.

 

Frictionless contact between the spring and the slot is crucial. Many times the reason the spring does not make the hammer walk up properly is that dust and dirt in the slot are causing sluggishness rather than a weak spring.

 

Prepare to graphite the top of the repetition lever and jack head and tail. Scrape the top of the repetition lever with a razor blade first to remove dirt and to even the surface if there has been wear by the knuckle. Apply the graphite (in stick form) and burnish with a polished steel burnisher until very shiny. Only the true nit-picky technician will realize the joy of shiny little jack tails all in a row upon reassembly. The commercial graphite suspended in alcohol solution contains gum arabic so it’s not suitable for whippens. Even when burnished, the prepared graphite still has too much grab. After burnishing, remove excess graphite with a gum art eraser.

 

Look carefully at the whippen cloth where it contacts the capstan screw. If it is very moth eaten, saturated with paste graphite, or heavily worn it will have to be replaced. The new cloth can be glued with either white glue or contact cement but remember that the white glue will have to be clamped. Only the front and back edges of the cloth are glued as the middle goes over an underfelt and is not glued down. The easiest way to get a snug fit is to glue one end first and then stretch it over the underfelt tightly to the other end.

 

Use a brass bristle brush to clean and resurface the drop leather. These usually hold up well but if there is any foreign substance (glue, coffee, or liquor) on them they will have to be replaced. Needle and rough up with sandpaper (150 grit) the felt on the jack and repetition lever buttons. Check for looseness in the wood - they’re a possible source of noise. If any are loose remove the screw, glue size with very thin hot hide glue, let it dry, and replace the screw.

 

There are glue joints to check, if the jack is in two pieces (Steinway) then make sure that they are all tight. If the jack has been hopelessly damaged then pin another in its place. Make sure that the repetition lever flange is also tight.

 

Very old Steinway whippens may have no jack buttons or spoons. These can be added by drilling and screwing in the parts. If the old felts are still there they can be salvaged and usually regulate very nicely. Jack position can be changed by peeling the felt slightly or by adding a small shim in the back This may seem very tedious but many of these old felts never have to be touched to reposition the jack and hold their regulation very durably once properly positioned. I usually try to retain this feature for the sake of preserving the original mechanical design.

 

Make sure the spoons are tight in their holes and clean them if necessary to insure noiseless contact. The Schwander-type whippen has a silk cord that holds the spring in place. These rot and have to be replaced with cord available from supply houses. Simply clean the hole gently with a tapered reamer and put the ends of the new loop in the hole. Press a toothpick dipped in white glue into the hole with the cord and break off the toothpick when dry.

 

The jacks may have become off-centred in the mortise. Rebushing or repinning may solve the problem so check first for sloppy pinning. If the jack is the proper tolerance then you may correct the problem by bending the pin slightly. Hold the proximal end of the whippen on the 90” edge of a table (on the side with the largest gap) with the jack hanging unsupported in the air. Gently tap the top of the jack, with a small hammer, on the edge that is farther away from the mortise. After correcting the position you will have to again check the pinning to make sure you haven’t loosened it too much.

 

Check the pinning on all the centres. If there is a green deposit present in the wool bushing you will have to rebush. Weigh all the centres using gram weights to measure proper friction. This step is the basis for a fine even regulation. We all know that centres  have to be free, but how free? Gram weights can be very accurate in determining this. Tie the gram weight with a light thread and hang it on the part to be measured and watch the speed with which it falls. The part should fall slowly with the weight attached. The repetition lever should weigh out at three to eight grams, the jack should be one to three grams and the whippen flange should be three to eight grams. Pin the centres tighter (more grams) in the summer and loser (fewer grams) in the winter. The really important point here is that all centres be the same tolerance from part to part. Besides the obvious problem of noise, a repetition lever centre can be so loose that the spring cannot be regulated properly. The spring will appear too strong and there may be problems with backcheck. Weakening the spring on a Steinway will cause the jack to be too slow. The repetition lever centre must be tight enough so the spring will cause the hammer to walk up slowly and still be strong enough for fast jack return.

 

Lastly, the rest cushion can get rather dirty-looking and still function if they’re not falling over to one side. Many older instruments and some new ones have no cloth cover over the felt. I usually try to retain the type present on the action as I find it. Damper felt is fine for the underfelt and bushing cloth (thin) is fine for the cover. Glue on the white felts first and let dry. Then glue the front of the cover to the wood. Wrap the cover over the white felt and glue on the back. Glue is never applied between the white underfelt and the cover.

 

By now, I’m sure you’re thinking there is a mad man in your midst, but don’t judge this procedure too hastily. Not all whippens need all of the above mentioned restoration. Many only need examination for problems and a few repairs. Of course you have to decide when to replace a whole set of felts or when to do just a few. I usually try to match carefully the existing materials when there are just a few unsatisfactory items. If there are more than several undesirables, I usually replace all 88 of the objects in question. One may argue that the labour cost is prohibitive but the actual materials involved in restoring a whole set is a fraction of the cost of new parts.

 

Anyone can be taught to graphite a jack and the possibilities are limitless (spouses, children, friends, boring dates) as to who can be recruited for such exciting fare. Also, if you have never embarked on a project like this, you have missed an educational opportunity that will serve you well in future troubleshooting ventures. That occasional elusive click may turn out to be a loose part that you never dreamed could be the problem, and once you have refurbished a whole set of whippens you are better prepared for such events.



Pre-Voicing

When confronted by tone problems, many piano technicians seem overly anxious to find a quick remedy by using voicing needles or lacquer. Both needling and lacquering are important elements in the over-all voicing picture; a skilled technician must know when and how to use voicing needles, as well as how to prepare and use lacquer solutions for hammer hardening. The point is this: both these methods are ultimately destructive to hammer felt, and shouldn’t be used until all other possible solutions have been explored. What are some of the things to check before we begin to needle or lacquer?

 

A. Before thinking about voicing we must make sure the piano is well tuned. We all have had clients comment upon the remarkable change in tone or volume after a good, solid tuning. A major pitch change will most assuredly change a piano’s voice, so tune it first. As part of our preliminary tuning procedure we must consider several areas which can affect tone:

 

1) Tighten all plate screws.

 

2) Seat strings properly, using a wooden or brass tool to tap them down on bridges, aliquots, duplex bars, and counter-bearing bars. This can clear up false beats, and clean up a muddy sounding tone.

 

3) At this time, check and, if necessary, correct the tuning of the duplex scale - if the instrument has one. You may notice a brighter, louder tone when the duplex strings properly reinforce the harmonic structure of a given note.

 

4) We also double check the location and tension of stringing braid. A minor point, but one which can either add or eliminate high partials without using needles.

 

B. Next, we consider the role of proper action regulation in piano tone-building. Perhaps this is an obvious point, but sometimes we overlook regulation problems and are quick to blame hard or soft hammers, old strings, etc., for tonal problems. Some areas of regulation seem to have a greater effect on the tone we hear:

 

1) Of primary importance in this area is the bedding of the keyframe. This foundation for all our regulation has a very direct influence on what the artist hears, both physically and psychologically. Generally, an improperly bedded keyframe will cause loss of power and consequent loss of tone.

 

 2) Another major item to check here is the proper hammer striking point, especially in the high treble. Many a hammer has been unnecessarily hardened, when the problem was really an incorrect strike point. Check by experimenting- results here are immediately obvious.

 

3) Travelling of hammers and shanks can affect tone, so do this work carefully.

 

4) Of utmost importance is the actual hammer-string contact point: each hammer must hit its strings squarely and simultaneously. Space the hammers to the strings. File the hammers if necessary to remove dead felt, and to provide a perfectly level surface at the strike point. Later, we will discuss filing to bring up volume and brilliance.

 

After checking that the hammers are level, we check for level strings. String levelling is much over-looked, both by manufacturers and technicians. Here is an area that can dramatically improve tone. The symptom of an unlevel unison is an unclean, almost buzzing sound. It can also seem like a false beat, and can make tuning difficult.

 

Check all unisons by pulling the hammer up to the strings and blocking it there. Use either a hook to support the shank from the bottom, or use the method of pushing up on the bottom of the jack and not allowing let-off to occur.

 

When the hammer is blocked in such a fashion, the strings are individually plucked. It is immediately apparent if one or more strings is not level. The high strings will sound, while low strings will be deadened by the hammer. Carefully lift all low strings to the level of the high strings. Use a tool available from supply houses (string lifter) or make yourself a stringing hook using heavy gauge music wire epoxied into a handle of some sort. 

 

In string levelling we are actually pulling up and slightly bending the wire near the agraffe or cape bar. This technique is easily learned and is an important part of pre-voicing. (An added bonus of level strings comes when we regulate dampers- especially in fine adjustment of the tri-chord wedges.)

 

C. The piano can be well tuned and properly regulated, but still lack volume or brilliance. Don’t lacquer yet. If there is plenty of felt on the hammers, another filing can increase tone quickly. Getting down closer to the hammer molding, the layers of felt are harder and can create a more brilliant tone. This is especially useful to bring up sound in the high treble.

 

Some manufacturers count on the technician to remove layers of felt as the first important step in tone regulation. This is in addition to the removal of the outside layer of “dead,” slightly cupped felt found on all new hammers.

 

Finish your hammer filing with a fine garnet paper (220 or finer). This final filing is done in only one direction, and is commonly referred to as “polishing” the felt. Again, we can effect a major change in brightness by this last touch.

 

Now, if we still can’t get enough high-quality sound, we can lacquer to harden hammers. Lacquering is a major subject in itself, and won’t be discussed here. Now also, if we have uneven tone, we can get out our voicing needles. Again, this is a big subject and can’t be considered in this space.

 

A final bit of pre-voicing, obvious but often overlooked: room acoustics. A move of a few feet can alter a piano’s tone in many different ways. Placement of rugs, pillows, curtains, etc., also have a great influence on volume, sustaining power and quality of sound. , If these acoustic variables can be altered, do this first - hammer voicing must always be the last step, after everything else has been adjusted for ultimate piano tone.

 

So, next time you are anxious to get out the “juice” bottle, or to perform “acupuncture” on someone’s piano hammers, stop for a moment and consider all other possibilities first. Only then should you proceed to use your other voicing skills in a judicious and craftsmanlike manner.  




Concert Piano Preparation – part 2 (Conclusion)

The primary concerns in concert voicing are evenness (funny how often that word comes up in piano work, isn’t it?) and colour flexibility. By evenness, of course, I mean that notes should not stand out from their neighbours by being either too powerful and brilliant or too soft and mellow. By colour flexibility, I mean that the tone should be able to change to meet the artist’s needs. For instance, a note should sound mellow or “pearly” when played pianissimo, but should sound brighter and have more “bite” when played at louder levels. The best way to achieve these results in voicing is to start out with good quality hammers and a solid regulation, then follow the tried-and-true methods laid out in Franz Rudolf Dietz’s “Grand Voicing “(1). Short-cut voicing methods may make a quick and obvious difference in a piano’s sound, and may be fine for some home pianos, but I prefer the slower and more controllable traditional voicing techniques, especially when dealing with fine concert instruments.

 

Because pianists do not all have the same preference as to piano tone, no one piano and no one voicing are going to keep everyone totally happy. I recall attending a piano recital where a faculty friend approached me at intermission and said, “Steve, I think your piano is too bright.” Another friend, overhearing, said, “I think it sounds gorgeous. It’s perfect!” A few minutes later, I ran into a technician friend who thought the piano sounded nice, ‘but it could stand to be a bit brighter.” Three different people, three different opinions. That incident taught me not to take any one person’s opinion too seriously. Naturally, the best approach to voicing pianos that are used by a wide variety of performers is to keep the hammers in good shape (some technicians file the hammers after every performance!) and keep the sound as even as possible. I try to make the overall tone quality match my conception of what a piano should sound like, always remembering that it’s generally better to err in the direction of “too brilliant” rather than “too dull” where a concert piano is concerned. If a particular artist requests changes in a piano’s voicing, I will usually attempt to meet that request, but now we’re entering the realm of “working with people.”

 

The Artist

 

Whenever possible, I like to meet with the pianist during the piano selection process. If the artist has chosen the piano prior to coming to the hall (some choose a piano solely by brand name), or if there is no choice available, I try to meet the artist at the beginning of rehearsal time, when the pianist is first trying the instrument. I introduce myself, ask the performer if there are any problems with the piano, and after any necessary discussion, I leave.

 

Where voicing is requested, I prefer to have the pianist present while I voice the piano. This approach helps eliminate misunderstandings, especially when I can get the pianist to participate with me in the process by trying the piano after each stint of needling or filing. If for some reason the pianist can’t be on hand for this type of work or to try the piano after the voicing is done, I’ve found he or she is usually reluctant to have any work done besides tuning. That’s for a good reason: they would rather know exactly what to expect when they sit down to play at concert time. (2)

 

Other People

 

Besides the artist, we often deal with promoters, stage managers and stage hands. The rule with all these people is the same: respect their needs and their problems, and make a real effort to help them. Where their needs conflict with yours, seek a compromise.

 

Promoters appreciate a technician who will be at the hall on time and who, if there is a delay on stage once he arrives (which happens often), doesn’t fuss and fume and threaten, but waits patiently and does the best possible job with the time remaining. Most promoters don’t mind if you spell out initially how and when you want to be paid. I like to be paid immediately after doing the work, and I ask, before even scheduling the appointment, if this is possible. I also ask to be scheduled in when the stage will be quietest.

 

A major stumbling block to many technicians is the fact that we must frequently deal with a certain amount of noise while trying to tune for performances. This noise comes most often either from stage hands setting things up or from musicians who want to warm up in the stage area while you tune. Again, the best way to minimize this problem is to request a time for tuning when the stage will be quiet. Since this is not always possible, I try to cultivate a friendly relationship with the stage crew, always remembering that a little humour can help a lot. Personally, I find it hardest to compete with other musical instruments when I’m trying to tune. While I sometimes will ask the musician (politely) if the green room might not be available for warming up, I find that even newly acquired friends on the stage crew can be a big help in keeping musicians out of earshot until I finish. Realistically, however, there are still times when we have to tune around or through more noise than we would like, and I suppose that each technician has to decide his or her own tolerances and limitations in this area.

 

The tuning and preparation of concert pianos does hold special frustrations, but for me, the rewards outweigh them. Beyond the obvious and superficial benefit of “fame by association,” a concert piano technician has the heady challenge of preparing some of the world’s best pianos for some of the world’s best pianists. In this sphere of our craft, we sometimes find ordinary limits removed, and we have a chance to see (and hear) what we can really do. When that happens, and when we succeed in responding to the challenge, we can enjoy a measure of true satisfaction. Although music critics don’t make mention when a piano is exceptionally well tuned, voiced or regulated (however, they will mention anything they think is not right about the piano!), the artists sometimes do. When they do, I feel that I’ve done something really worthwhile. And to me, that’s success.

 

Notes

(1) Franz Rudolph Dietz, “Das Intonieren von Fluegeln” (Grand Voicing), (Frankfurt: Verlag das Musikinstrument, 1968). The text is written out in German, English, French, Swedish and Italian.

(2) Speaking of pianists needing to know what to expect at concert time, consider seemingly small details as the height of the bench - don’t adjust it when you tune after rehearsal. Also, don’t clean the keys after tuning (unless specifically requested to do so); clean keys are sometimes slippery!




Concert Piano Preparation – part I

Most piano technicians have the opportunity to experience many different facets of piano work. While comparatively few of us actually specialize in tuning and preparation of fine concert instruments, I think most of us, at one time or another, are called on to perform this service. My first concert tuning experience came when I was barely three months out of tuning school. The pianist was famous and I was nervous. Nothing really terrible happened on that occasion, and for the next few years, one of my regular duties was to care for that same piano whenever it was used in a concert. When I took this university job a few years ago, I assumed responsibility for a stable of concert grands now numbering five (representing three different makes) which are used for both performing and recording. In addition, I frequently take calls to tune for performances at different halls in the city. Since most technicians may expect to do this sort of work at some time, I would like to share some of what has “rubbed off” on me so far, during my own continuing education.

 

Like nearly all areas of piano work, concert piano preparation consists of two basic types of work: working with pianos, and working with people. These two aspects are equally important and necessary; no matter how brilliant the technician, if he can’t communicate and assume certain responsibilities toward the people who are necessarily involved with the piano, he will ultimately fail. I’ve found that customers are usually quite willing to exchange a small amount of technical brilliance for a large amount of conscientious and responsible behaviour. On the other hand, a technician may have “personality plus,” always be on time, and charge the lowest rates in town, but without technical expertise, will not be able to “cut it” where piano performance is a critical factor. So, both are necessary. Let’s talk first about working with pianos.

 

Tuning

 

Even if you have the job of caring for a given concert piano on a long-term basis, tuning is the job you will be asked to do most often. Tuning is still an indispensible job before each performance. When we speak of concert tuning, we imply that it is somehow different than ordinary, everyday tuning. Actually, I think of only one real difference.’ That difference deals with the concept of “point of diminishing returns,” a point which is reached much sooner with the average home piano than with the average concert grand. What it means is this: on a good concert grand, it is worth our time to be especially nit-picky about our tuning, because the extra time spent translates to a discernable difference in the finished product. This would apply to the areas of regulation and voicing as well.

 

Within the realm of “concert” tuning, every part of the tuning is important, but we must give special emphasis to unisons and tuning stability. At this point, I still hold with the belief that beatless unisons are important to a tuning because of the crisp, clean effect they give it. I have yet to be convinced that a unison with a two-cent spread is in any way desirable. Unisons drift rapidly enough without our setting them “on the edge” to begin with, and the average layman will complain about bad unisons long before hearing misaligned octaves or uneven temperaments. For these reasons, we should pay close attention to unisons, going over them two or even three times in the course of a concert tuning.

 

The other area of special emphasis is tuning stability. Conditions are often aggravated by circumstances surrounding the piano, such as temperature and humidity fluctuations in the hall, the fact that concert instruments are often brought in from somewhere else, and must readjust to the hall, and the fact that, in performance, a piano often undergoes extremely heavy playing. In light of these factors, we must make sure that, when we tune the piano, we are hitting the keys at least as hard as the pianist will, and that, before tuning, the piano has acclimated as well as possible.

 

I will never forget the time I had to hurry through a concert tuning and managed not to hit some of the keys as hard as I should have. Sitting in the fourth row at the concert that evening, I was mortified to hear Bb50 suddenly become a very wild unison during a stressful part of the Schumann Fantasy. Thereafter, the note was played often in some very exposed melodic passages, and I cringed each time I heard it. At intermission I hurried onto the stage to touch up the unison, and was greeted by a smattering of applause. As I bent over the piano, someone shouted, “It’s the Bb!” Needless to say, I was thoroughly embarrassed.

 

By thoughtful practice, a technician can overcome problems with unison tuning and tuning stability. Tuning tutors can be helpful even to experienced tuners, sometimes spotting small deficiencies which have become ingrained in our technique over the years. I find it instructive to watch others tune and see their methods of pin-setting. By experimenting with different hammer techniques and measuring slippage with a good electronic tuning aid, a tuner can learn a lot about which method works best for him or her. A machine with one-tenth cent accuracy is a great help in honing unison tuning as well.

 

One other aspect of tuning that is sometimes critical is the pitch of the A itself. While a small error is usually not disastrous in a home tuning, it may well be in a concert tuning, particularly, where other instruments (especially oboes and flutes) are involved. Many musicians are acutely aware of pitch and how a change in pitch can affect their sound and performance. Even if you feel this sensitivity is more psychological than real, you would be well advised to adhere scrupulously to setting A as close to 440 Hz. as you can. Many musicians now own small electronic tuners, and some of them like to check the pitch of the piano, so the closer you can get the pitch to 440, the better off you’ll be in that respect as well.

 

Where conditions permit, I like to tune the piano thoroughly several hours before the performance, even before any rehearsal, and then return to go over problem areas again shortly before the performance. I find if anything is going to slip, it will do it during rehearsal, and I can concentrate on such problems when I touch up the tuning before the performance.

 

Regulating

 

Although when talking about regulation we usually think about the action, one regulation item of extreme importance to many performers is pedal regulation. So many aspects of shading and nuance in fine playing are controlled by the pedals, we need to be sure that the damper pedal lift is even throughout, that the shift pedal moves the action noiselessly and provides a different tone colour (but not too different!) and that the sostenuto  mechanism works properly.

 

Uneven damper lift at the pedal can cause a performer real grief. The sound of a damper coming down later than the others around it as the pianist releases the pedal slowly in a pianissimo passage can utterly destroy the mood and effect of the piece. A late-lifting damper, on the other hand, makes it hard for the pianist to be sure each note will be sustained if the pedal is only partially depressed (the damper pedal is more than an on-off mechanism to a good pianist). If there is any unevenness in damper lift, such techniques as half-pedalling become ineffective at best.

 

Some artists depend on the shift pedal more than others, and what they want it to do tends to be a personal matter. If it doesn’t provide enough change in tone for a performer, this change can be increased by light needling on the left side of the hammer crown. If there is too much change when the shift is applied, try brushing the hammer crowns with a suede brush to soften the felt in the string grooves.

 

With regard to the action itself, the word is evenness, especially in aftertouch, touch weight, and let-off. Another important item is the repetition spring.

 

The aftertouch determines, to a large extent, how comfortable the pianist will be in playing a particular piano. If the aftertouch is too great, the action will feel slow and cumbersome. If too little, the pianist will complain of a “too-shallow” touch and will feel a lack of solid power.

 

For touch weight, most artists prefer an action requiring between 50 and 55 grams of downweight on a concert piano, although they sometimes like a little heavier action on a practice instrument. Again, the really important factor here, and with let-off, is evenness from note to note.

 

Repetition springs are often set too strong, probably by technicians who feel that if a little is good, then a lot is better. With overly strong repetition springs, particularly in the tenor and bass, a pianist will have difficulty controlling the action in soft playing. Set properly, the springs should not cause the hammers to jump up jerkily from checked position, but to rise smoothly and without hesitation. 

 

To be continued



Fine Tuning

I have completed my 30th year of tuning and general piano service and during all of that time it has been my aim to improve the quality of my work in any way possible. I believe most tuners have this same aim.

 

I have been successful and my work has been acceptable to my customers all along, but I have come to realise during the last five years that there are many things to be learned about fine tuning. And many of them are not taught to the students who study the theory and practice of tuning.

 

This is not to say the theory of tuning, as taught in the best schools, is faulty. On the contrary, it is a theory which has developed into an exact science.

 

It has been correctly described as a closed mathematical system which, if followed faithfully, will result in tuning all intervals, correctly tempered, and all octaves tuned as “dead” or perfect octave intervals. But even this result, if it could be achieved, would not necessarily be entirely pleasing to the critical musician.

 

There are several reasons why this is true and every tuner should know all he can about them, and about how he can best overcome the difficulties they present.

 

First: -All tuning, except unison tuning, is done indirectly; that is, in tuning any interval, octave included, we are comparing coincident harmonics of the two tones being sounded.

 

Second: - The harmonics of a piano string, which is under high tension, are not exact multiples, in frequency, of the frequency at which the entire length of the string vibrates.

 

Third: - To tones which are either very high or very low in frequency, the human ear does not assign pitches which are directly proportional to their frequencies when compared with tones in the middle frequency range. In other words, our sense of pitch is a subjective discernment for each individual, and it may be considerably different from true pitch theoretically determined by the correct frequency for that pitch.

 

Fourth:- I doubt it’s possible to set an absolutely perfect equal temperament, probably because the harmonics on which we depend are not true harmonics of the fundamentals from which they arise. This should not, however, prevent any of us from setting Bach temperament as perfectly as possible and, on a good piano, it is possible to set a very good temperament indeed.

 

Fifth: - I also doubt it’s possible to tune a perfect octave without resorting to tests other than our evaluation of a “dead” or beatless interval. A number of years ago, a technical editor for a piano trade magazine warned all tuners “never trust an octave.” My experience has borne out the value of his warning. In fact, I have found that there is a considerable range of frequency over which an octave is acceptable to my ears, but the same octave will often be found to be less than perfect when one of its members is made a part of some other interval which is known to be correctly tuned.

 

 

We must recognize that perfection in tuning is not possible, but we should always strive for it. And as nearly perfect an equal temperament as we can set is a must, for it determines the harmonic pattern upon which all of the rest of the tuning depends. The quality of the piano is a limiting factor, as is our skill, but in the matter of skill it is our responsibility to do all we can to improve it constantly.

 

We recognize also that we are dependent upon coincident harmonics for practically every step in tuning. And also, that coincident harmonics may create some of our worst problems when they result in dissonant intervals. Therefore, they become the basis for some of our most useful tests, especially when they are coupled with some knowledge of chord structure. With this background of recognition of the possibilities and the problems we face I would offer these suggestions for achieving what we term “fine tuning.”

 

First: - Become familiar with the piano keyboard so that you may test any combination of tones likely to be used in piano music. Those who play the piano may not know how careful the tuner may have been with his temperament or how much attention he has given to tuning perfect octaves, but they will be quick to notice any interval which is dissonant to the degree that it offends the ear. So, we must know what degree of dissonance is correct in the equally tempered scale, for it is, after all, a compromise whose greatest advantage is that all scales in all keys are equally acceptable, though none may be said to be perfect.

 

Intervals used in polyphonic music include seconds, major and minor thirds, fourths, fifths, major and minor sixths, minor sevenths, octaves, ninths, tenths, twelfths, and so on. And most of these intervals, as well as others, have their uses as tests of accurate tuning.

 

Second: - Do not expect to leave a piano accurately tuned with a once-over tuning if any considerable pitch change is to be made, because the change in down bearing on the bridges during tuning will defeat your best efforts to achieve accuracy.

 

With a reasonably acceptable scale at the proper pitch, I strip mute the middle and treble sections of the piano. On uprights, above the treble break, the loops in the muting felt must be pushed down behind or preferably below the dampers, but this is not too difficult.

 

Then I set as perfect a temperament as possible, realizing that not only are fourths and fifths important intervals, but that major and minor thirds and sixths, while more dissonant, must also be acceptable intervals within the temperament octave. Also that fourths, fifths, thirds and sixths, both major and minor, have their proper beat rates and that these rates increase in frequency as we ascend the scale. This is true, of course, throughout the entire piano scale. The progression of .beat rates and its evenness is one of our best tests of the equal temperament we try to achieve.

 

Third: - When I am satisfied with my temperament, and sometimes I must be satisfied with a compromise on spinets and small grands, I proceed with the bass tuning. My reason for doing this is, that having tuned the bass, I will have available for tests of treble tuning the intervals of major and minor thirds, fourths, fifths, sixths, tenths, twelfths, double and triple octaves. I can demonstrate the advantages of these tests more quickly than I can describe them.

 

For the bass tuning I have found this method fast and effective. And rarely do I have to make a correction after having applied the tests 1 use for each tone as I tune it. For instance, after having tuned E32 to E44 as an octave, I use the minor third E32-G35 and the major sixth G35-E44 as the test of a perfect octave. If the best rates of these intervals are identical, the octave is perfect.

 

Usually, I test the tone being tuned with its third, fourth and fifth above and sometimes with the sixth. In small pianos, E32 may be a wound string and these tests will indicate whether as light compromise of the octave is needed to make the other intervals more acceptable and the progression of beat rates more even as the tuning descends the scale.

 

These tests are useful and conclusive enough until the tone F21 is tuned and by that time thirds, fourths and fifths have beat rates that are very slow and hard to judge accurately.

 

Another test is now available and it is helpful through the range of the next octave and sometimes lower. After tuning F21 to F33 I use the interval F21 -Eb43 (an octave plus a minor seventh) and observe its beat rate. It will be rather rapid and should be the same as that of the major third C#41 -F45. If these beat rates are identical, the double octave F21- F45 should be perfect. This test is much more conclusive than testing the octave F21-F33, if only because the more rapid beat rates are easier to compare.

 

In the extremely low bass double octaves, triple octaves and a comparison of beat rates for descending tenths and octave tenths may be used. Of course, thirds, fourths and fifths may be used as tests of bass tuning whenever their beat rates are fast enough to be judged and compared. In short, any test which confirms that a tone is tuned to its proper position within the entire scale pattern is useful.

 

Fourth: - In treble tuning, the first string to be tuned is F#46. After tuning it to F#34, I test the fifth F#46-B39. If the fifth beats too fast I know the F#46 is too low or much too high, which is unlikely, since the octave is at least nearly perfect. Re-tuning the upper F# I test it with D30 (a tenth) and compare this beat rate with that of D30-F#34 (a major third). These beat rates should be identical and I should have a perfect double octave with F#22. Fourths and fifths down from F#46 should test out right, also. This series of tests (fifths, tenths and thirds) is very effective and, when confirmed by perfect double octaves, may be depended upon to a point well above the treble break From about C64 it is sometimes helpful to add triple octave tests. If a double octave seems perfect and the triple octave is beatless but gives the sensation that the highest tone just tuned is flat, it is likely the range at which the ear is not a reliable pitch indicator has been reached.

 

On very fine pianos, octave. stretching is sometimes not necessary at all, but on those pianos where it seems necessary in order to satisfy the ear, it is best to tune the octave beatless and then to raise the upper tone just enough to satisfy the sense of pitch, but not to leave an octave that beats enough to be dissonant.

 

The purpose of the tests which I have described is to “box in” each tone, as it is tuned, among as many reference points as possible, once each reference point has been established as correct. In this way perfect unisons and octaves, correctly tempered fourths and fifths, thirds and sixths, each with its proper degree of dissonance, will fit into the best harmonic pattern for the particular piano being used.

 

The final step, the unison tuning of the muted sections, must be as exact as possible and here we have no tests such as intervals provide, so we must rely on concentration and the finest hammer handling technique we can develop. I have found that I can get a better unison by tuning each outside string to the middle string with the other string muted, except that when false strings are encountered it is sometimes possible to partly counteract the false beats of the faulty string by slight de-tuning of the other strings of the unison.

 

We may say that “fine tuning” is the closest adherence to theoretically perfect intervals and unisons which may be achieved without leaving dissonances or sensations of improper pitch which the ear will not accept.





Grand Regulation – part XXX

Step no46 Check string level / damper seating  

 

Most technicians know that piano wire, even after being strung  and pulled up to tension, still retains a natural curve as a result of being reeled upon a spool during manufacturing. Because of this natural curve, the three strings (or two) which make a unison may or may not be perfectly level at the point where the hammers strike and where the dampers seat. Irregularities in string level may also be caused by the holes in the agraffes not being perfect.  Whatever the cause they must be corrected.  If one string in a unison is higher or lower than the others, problems in voicing and damper sealing are sure to result.

 

 

Since the string level affects both voicing and correct dampening, I find it easiest to match the string level to the dampers, then alter the tops of the hammers to finish matching the hammers to the strings. Theoretically, all strings should be perfectly level, with all of the tops of the hammers also perfectly level, and correct dampening on every note. However, being one who is more practical than theoretical, I have a tendency to leave the dampers alone if they are working fine! Play each note staccato, listening for the familiar “after ring” which tells that the dampers are not seating correctly. Don’t forget also to try the dampers using a lighter, legato touch, as well as using the sustain pedal. If any dampers are heard to “ring through,” feel the string directly in front of the damper head and check for a problem in the level of the strings. 

 

 

Not all problems with dampening are caused by string level. Sometimes the damper head is bent side to side or front to rear. Maybe the damper-to-string alignment is off. On trichords, if the middle string is dampened but one of the outer strings is not, try cutting the middle of the trichord a little deeper. There are numerous other reasons for incorrect dampening besides these. But if the strings are felt and one of the unisons seems to be too low or too high, try leveling the strings. When one string is low and the others are high, the obvious solution is to raise the low one. However, some technicians   would rather not raise two low ones to match one high string when one is high It is possible to lower one string. Whatever your preference, the end result should be to get all three unisons level.

 

 

To raise a low string, take a string hook, as used in restringing, and place it under the offending string between the agraffe and the damper. Slide it back and forth with a slight upwards motion a couple of times. This process is much like voicing in that you can always do a little more if needed, but it becomes a problem when you’ve gone too far. Don’t run the string hook too close to the agraffe as you want to put a slight bend in the wire rather than a crink. It is possible to break a weak agraffe, so put only a slight upwards pressure on the string. Retune the string and check for correct dampening.

 

As mentioned above, if one unison is high to the other two, you have a choice. The high string can be lowered, or the two lower ones can be raised with the method just shown. If you prefer to lower a high string, take something softer than the wire, a piece of brass or hard wood (not a screwdriver) and gently run it up and down the string using a slight downwards motion. This is a little trickier, and perhaps not as permanent as raising low wires. 

 

 

Step no47 Check sostenuto tabs for evenness, adjust knife angle  

 

The evenness of the sostenuto tabs should already have been checked while performing steps no43 & 44, the dampening lift form the key and lifter rail. If these previous steps were done correctly, all tabs will be in a straight line. If they are not, go back to step no43 and redo, as any change in the height of the damper lever to get good tab alignment will cause problems with the damper lift from the key and lifter rail.  

 

Adjusting the sostenuto knife angle rather simple. Adjustment is made by varying the length of the sostenuto pedal rod. Looking from the treble side of the piano at the rod, it should be at 5 o’clock in its rest position, 3 o’clock in the raised position. 

 

 

Step no48 Adjust sostenuto knife in / out and up / down  

 

Now that the tabs are perfectly even and the knife angle is adjusted, all that is left is the in/out and up/down adjustment of the sostenuto rod itself. Taken in this order, working on sostenuto systems becomes considerable less painful. If you can’t remember anything else about the sostenuto rod, remember the distance 1/8“. The rod cannot interfere with the normal playing of the piano. All tabs must clear the rod when not using the sostenuto pedal.  On the other hand, when the pedal is played, it must catch and hold firmly any tabs in the raised position. Adjust the rod in/out to give 1/8” clearance between the rod itself (not the knife part of the rod) and the ends of the tabs.

 

 

With the sostenuto pedal in the down position, we want to raise any tabs corresponding  to the keys being depressed but we want them raised higher than the distance the key will raise them. The damper levers when raised by the sostenuto rod should be pushed well into  the felt of the damper stop rail. This   will eliminate any unwanted noise from other tabs coming up and hitting the knife from underneath while the sostenuto pedal is in use. This adjustment is far more critical on pianos where the tabs are not hinged with a return spring. These stationary tabs will really cause a noise if the rod is not so adjusted. Make this adjustment by leaving 1/8” between the tops of the tabs in the down position and the bottom of the sostenuto rod. This adjusts the rod up / down position.

 

 

Virtually all grands are made with the sostenuto rod connected to the belly of the piano. By removing the action, access can be gained to work freely on all the parts. The exception is the American made Steinway. The sostenuto rod is connected to the action frame. On these pianos, any adjustments on the placement of the keyframe on the keybed will change how the  sostenuto works. To regulate the in / out  and up / down on these pianos,  place the action in the piano and secure its position with the cheekblocks. By playing notes and catching them with the knife, I can see with the aid of a light how the rod is working. Remove the action, adjust, reinstall and check for correct positioning.    

 

 

Step no49 Adjust shift pedal rod length and stop screw   

 

 

Depress the shift pedal slightly and place a piece of paper in between the left side of the action and the keyframe stop block. Release the shift pedal and pull on the paper. The paper should be held firmly in place. If it comes out, the shift pedal rod length is too Iong and is holding the action out of place.  Adjust the rod length until there is no lost motion but make sure that the action is secure against the stop block.

 

 

Now depress the shift pedal fully.   Look at the string grooves in the hammers on the three string unisons. The shift pedal stop screw on the treble side of the piano should stop the action such that the string groove for the left unison is now directly under the centre unison. Some technicians prefer to adjust this screw out a bit further so that the groove for the left unison is not quite under the centre string. Whatever you prefer is fine. Just make sure that the action shifts at least half a string groove but not more than one groove. Actions that shift too far run the risk of having  the hammer hit the left string on the upper note, causing a bit of discord! Check to make sure the action returns freely and no noises are heard while shifting. 

 

 

Step no50 Adjust strike point, tune, voice  

 

 

The final regulatory step in the 50-point checklist is to adjust the strike point. This is done by playing note 88 and listening to the quality of sound. The action is freed at the treble by removing the keyblock. Pulling the action out or pushing it in while playing the last note will tell just where the ideal strike point is. Assuming that the strike point was correctly adjusted in the past and has now changed because the hammer has worn, the action needs to be a little further in. By sight, the hammer should just clear the capo d’astro bar. By sound, it is correctly positioned where the tone is the clearest and loudest.

 

 

If the action won’t go back as far as you want it to, take a screwdriver and lift up the front of the keyframe using the guide pin as leverage. This will show if the action should be further in. After the correct position for keyframe has been found, loosen the screws golding the guide on the keyblock and reposition the guide to match the new keyframe position. Some pianos have an adjusting screw at the back of the keybed, so look to make sure this is not forgotten. The normal amount that a technician should be repositioning the action is around 1/32”. If you find that it needs a great deal more, either the action was wrong before you got to it, or someone did a lousy job of hammer replacement.

 

 

This ends the 50-point checklist as far as grand regulation goes. Following will be two “appendages,” one dealing with tuning, the other with voicing.  I apologise for stepping on anyone’s feet or for not having covered some aspects of the checklist in as much detail as others. Everyone has a favourite way of doing something. If anyone disagrees with what I have written, please write in and share your opinion. In that way, we will all benefit.



  

Grand Regulation – part XXIX

Combined Steps no43 check damper lift from key (1/2 dip)

& no44 check damper lift from lifter rail 

 

The regulation of the damper levers involves checking for evenness of the levers for proper sostenuto tab adjustment, how high the levers are for proper damper lift from the keys, and how evenly the levers lift from the lifter rail. Since these three aspects are inseparable, steps no 43 & 44 are combined for this discussion.

 

The time to worry about how well the sostenuto system will work is when the damper levers are regulated to obtain proper lii from the keys and lifter rail. The first principle to remember is that the levers must be perfectly level in the rest position. This will give a straight line for the sostenuto tabs, which is vital for the sostenuto system to function properly. Once the tabs are level, it is simple to adjust the sostenuto knife.

Never, never adjust the height of a single damper lever to correct for improper damper lift from the key or from the lifter rail unless the offending lever is not level with the others. Individual adjustment of damper lift from the key or from the rail is made by altering the thickness of the lifter felts. If the piano being regulated is brand new or at least new enough that the lifter felts are not worn, then proceed to adjusting the evenness of the damper levers. If the piano is older, especially if the instrument is being rebuilt, replace the key lifter felts and the damper rail felt.  Failure to replace worn lifter felt will surely result in lost time and big headaches.

 

The only way to replace the damper rail felt is to remove all of the damper wires (see last post’s discussion) and also remove the damper rail itself. Replacement felt should be of similar thickness and of sufficient density, like understring felt. While the lifter tray is out, lube the pivot bearings and return spring. Reinstall the lifter tray and damper wires. As was explained in step no42 in the last post, the damper wires must ride freely through the brass inserts in the damper levers. If the hole of the brass insert has been aligned and the wires still do not pass freely, reduce the size of the damper wire by light filing.

 

To regulate the height of the damper levers while maintaining a perfectly level line, I have a homemade aluminium square 1” x 1” x 46”. At each end of this square are holes large enough to let a threaded rod pass through. The rods are screwed into a wooden base. Nuts and washers are placed above and below where the rods pass through the square. This jig can then be placed inside the piano on the keybed directly underneath all of the damper levers. The piano action can also be placed where it normally goes, this jig not interfering since it is back under the levers!

 

Sample damper wires are screwed tight to their levers, making sure that the levers are too low in height from where they should be. These sample wires are at the extreme ends as well as selected places through the middle of the action. The nuts on the threaded rods are then screwed up or down to raise all of the damper levers higher or drop them lower as needed. The proper height for the lifter rail is found by installing the action and checking the damper lift from the keys. Usually this is adjusted so that the lifter felts on the back of the keys engages the damper levers at 1/2 the key dip. This specification can be changed a little up or down to make the action feel a lithe heavier or lighter as desired. Just remember that the point of engagement must be soon enough to lift the dampers high enough to clear the strings. Also remember that altering the way the action feels by adjusting the point of damper lift from the keys is ineffective hen the pianist plays with the sustainpedal down!

 

When the correct damper lever height is found, remove the action and tightenall of the damper wire screws so that the dampers are seated on the strings ml the bottom of the levers just touch the aluminium squares. If the damper heads move while tightening the wires, take a pair of pliers and twist the wires so that the damper heads are aligned to the strings. The screws should be quite tight. You do not want the heads to be loose enough to be able to get out of alignment after a few months of playing.

 

At this point, all of the damper levers should be perfectly level at the bottom, and all of the sostenuto tabs in a straight line. The point of damper lift from the individual keys and from the lifter rail can now be checked. The procedure for correcting too early or too late is the same whether it be for the lift at the keys or at the rail. If the felt needs to be thicker, shim with paper underneath. If the felt is too thick, simply remove a layer or two with a sharp knife (best for key lifter felts) or use a hot blade and scorch the felt (best for the rail). On some pianos altering the thickness of the felt is unnecessary.

 

Many European style actions have spoons which can be bent slightly up or down to regulate the lift from the keys. These and other actions also have capstans or let-off type buttons to regulate the individual lift from the lifter rail. If the above procedure is followed, that is, making sure that the level of the levers is correct first, then adjusting each key for lift and each damper for lift, the painful experiences of regulating the dampers will be diminished. That is not to say of course that there won’t be problems with some pianos.

 

Pianos which have split lifter trays are among the worst offenders. The procedure here is much the same. Remember to keep the sostenuto tabs level. This may require shimming between the two lifter trays to get all of the levers level.

 

Step no 45: Adjust damper stop rail

 

Relatively speaking, this step is quite easy to perform. With the action installed, depress sample sharp keys and check to see how much play the dampers have when raised above the level to which they are raised by the keys. Properly adjusted, the damper stop rail should give just a slight amount of play. This is for safety reasons when the keys are played more forcefully, compacting the front rail punching more, thereby lifting the dampers slightly further.

 

It is also to let the sostenuto system work properly on some pianos, Steinways being the most common example. Engaging the tabs with the sostenuto knife causes the dampers to raise slightly more than the key or sustain pedal does. Adjusting the damper stop rail is quite simple.

 

The sustain pedal stop has already been regulated so that the pedal lifts the dampers the same amount as the keys do. Remove the action and depress the sustain pedal fully. Loosen the screws for adjusting the damper stop rail. Reposition the stop rail with just a slight amount of play in the upward movement of the damper levers. Tighten the adjusting screws and reinstall the action.

 

Failure to regulate the damper stop rail properly will definitely create problems, so don’t overlook it. If the rail is too low, the pianist will complain of a rubbery feeling in the keys. The stop rail will act like a spring and try to keep the key from going all of the way down. Obviously, given time under this condition the stop rail felt will become depressed, and possibly the rail itself will become damaged. If the stop rail is too far up, the damper levers will bounce off of the rail and return to the lifter felts on the back of the keys with a very annoying thunk, which can easily be felt by the pianist through the keys.




Grand Regulation – part XXVIII

Step no 42: Check Damper Guide Rail, Ease or Rebush

 

All of the felts in a piano eventually ear out with age or use. One of the more overlooked areas of wear is in the damper guide rail. Perhaps the reason the guide rail, and for that matter, the entire damper system, is overlooked is because technicians hate to work on the dampers. Granted, the work is tedious, frustrating, and often a source of complaint from the pianist when it is not functioning correctly. However, the solution is to learn how to regulate the dampers, not to avoid it!

 

New pianos are much easier to work on since the felts are (or at least should be) in good shape. Before attempting to regulate the dampers, the first thing to check is the damper guide rail. One by one raise each damper head with your hand. Gently rotate it inside the hole and check to see if the damper wire has proper clearance. If it does not, then the hole will have to be eased. If it is too loose, then the felt must be replaced. Let us assume the worst and talk first about rebushing the damper guide rail.

 

Preferably this should be done in a shop, although it doesn’t have to be if you know how to do the job. Remove and store safely the action to the piano. Build a holder for the damper head / wires. I use a piece of firring strip 1” x 2” x 60”.  Blocks 3” x 3” x 1” are glued on to the ends of the fir strip. Holes are drilled about 1/2” apart, just large enough to fit the damper wires, but not so large as to let the dampers fall out if the fir strip is lifted upside down. Each hole is numbered and felt is glued onto the bottom of the 3” x 3” blocks.

 

Position the holder directly in back of the damper guide rail, letting it rest on the case, soundboard, strings, or whatever. Loosen all of the screws on the damper wire blocks. Carefully, making sure that the wires do not get bent out of shape, remove each damper head/wire from the wire block, pulling it through the guide rail and inserting it into the proper numbered hole in the damper wire holder. This is most easily done by starting at damper number one and working up. Spread the strings on each side of the screws for the damper guide rail, and remove the screws and rail. Either mark the screws for the holes, or else screw them back into their holes.

 

If the guide bushings were press fitted into the holes, removal of the felt will be easy. Where they were glued, take the damper guide rail to a drill press and punch the old bushings out. Make sure the holes are cleaned. Before the new felt is installed, I like to sand and refinish the guide rail to make it look as good as I can. Only the highest grade bushing cloth should be used to rebush the guide rail. Often this grade of cloth is not available domestically. Buy it in large sheets. Tear a strip from this sheet to the proper width to fit the guide hole. When the felt is inserted into the hole, the torn ends of the cloth will tend to mesh together at the seam.

 

Cut the cloth into 6” strips and taper one end so that it can be started into the hole. Insert the cloth through the guide rail hole from the top down. That is to say, the excess cloth will protrude from the counter-sunk side of the hole. Put a drop of glue onto the cloth on the counter-sink, and cut off the excess. I realize that not everyone likes to glue their damper guide rail bushings in. The only comment I can make is that those people must not have had the experience of pushing a damper bushing out the bottom of the hole while trying to ease a tight bushing! Use hide glue for this job. Reinstall the rail and dampers reversing the process used to remove them. Again, be careful not to bend the damper wires. When the wires are being inserted back into the wire blocks, they should move freely through the brass screw holder. This is a must when regulating the damper lift from the tray and key. If the wire does not pass freely into the hole, take a small drill bit (one smaller than the hole) and using the shank of the bit, not the cutting end, rotate the bit inside of the wire block screw hole, These brass inserts are just press-fitted and sometimes get turned a little when the screw is tightened against the damper wire. The drill bit will reposition this brass insert to allow the wire to move freely inside the hole.

 

Regulating the damper wires will be covered in the next two steps on the checklist. Now let us talk about what to do if a damper wire is sluggish and needs to be “eased.” To help find such ,tight bushings, one quick way is to raise and lower all of the dampers using the: sustain pedal. Any sluggish dampers will return slowly. Don’t come to conclusions yet, though, as sluggish dampers can be caused by things other than the damper guide rail. Also, although the dampers do return fast enough using the sustain pedal, they may still have excess friction at the guide hole.

 

Remove the action, and with a finger raise each damper lever from inside the piano. This is the only sure fire method that I know of to find excess friction in the dampers. Most of the time, the problem is not with the tolerance in the guide hole, but rather a misalignment of the damper wire! Sometimes a sluggish damper is due to a tight flange. Woe to the technician who immediately gets out his umbrella easing tool before checking the damper wire. Even worse is the one who tries to use silicone lube on the wire! Although the umbrella tool is acceptable when the bushing itself is too tight, neither the lube nor the tool will help if the wire is misaligned. The damper wire must run straight through the guide hole, as well as into the wire block. I use compound wire bending pliers to align the damper wires. I would say that 75% of the problems with sluggish dampers involve bending the wires to correct. For the other 25% where the bushing is indeed too tight, remember that it is not enough to ease the bushing felt. This is only temporary, and as soon as the felt swells back, the damper will be sluggish again. In easing tight damper guide rail bushings, the trick is to ease or crush the wood around the hole.

 

In much the same sense, when in a pinch because of lack of time, lack of money on the owner’s part, or lack of quality on the manufacturer’s part, if rebushing a hole is not practical, I will glue size the rail. This is particularly effective if the last technician over-eased the hole. Using a syringe with half water and half glue, I’ll put a drop on the rail right next to the bushing. This will swell the wood and size it much like fixing a worn centre hole in a key.

 

As a final note on step no42, there is a frequent problem with the dampers in the bichord bass section with pianos manufactured from a certain Asian company. Many times I have been called out to handle this problem, often being the third or fourth technician to be sent to correct the problem. The diagnoses have been many. One person says the problem is because the damper wires are made of too soft a metal. He eased the holes with his umbrella tool without crushing the wood. Soon the dampers were hanging up again. This he attributed to soft metal in the wires! Apparently, he thought the wires were bending with use! Another technician on the same piano said that the damper guide rail holes were drilled wrong causing misalignment of the wires Yet a third technician attributed the problem to the wrong kind of felt being used on the dampers. Believe it or not, it took me less than half an hour to bend the damper wires slightly so that they ran through the guide rail straight! No complaints have been heard from this customer in over a year.



Grand Regulation – part XXVII

Step no41: Rebush / lube pedals and trapwork  

 

This step is divided into two parts. Part I deals with the lyre and pedals. Part II concerns the trapwork. So important is the pedal / trapwork system that it should not be left unattended, ever. Each time a piano is serviced, whether it be for regular tunings, or for minor or major repair and regulation, the pedals and accompanying systems should always be checked. As I sit down to a piano for regular tuning and maintenance, I always take a quick look inside to see how dirty the soundboard is, making note of how old the piano is and what model or size it happens to be. As I install the felt muting strips, I first depress the sustain pedal to raise the wedge dampers, to keep them from getting pinched while installing the muting strips. While depressing the pedal, I make note whether it squeaks, feels out of adjustment, or possibly if the entire lyre assembly is loose or needs repairing.

 

If anything seems to need attention, I correct it before I proceed any further. Only a minute is needed to wiggle the three pedals to see if they are loose. While down there, Iook over the lyre to check if any glue joints seem to be breaking loose, and also check the condition of the felt and leather of the trapwork. When the pedals are found to be loose, the lyre is usually in need of being removed. The exception is for Steinways, or any other make where the pedals can be removed independently of the lyre. One of my lesser desires in life is to have to reinstall a Steinway, so if I don’t have to remove it, I won’t! How one person can hold a lyre up off the ground, make sure that two lyre braces fit into their proper slots, and still have a free hand to join the lyre to the connecting plate under the keybed is a wonder to me. Anyway, proceeding with Steinways, remove the plate in front of the pedals, keeping the screws orderly so that they can be installed into the same holes. Disengage the pedal rods from the back of the pedals and pull the three pedals out. Each pedal can be worked on separately. Unscrew the plate on the bottom side of the pedal and check the condition of the felt bearing. New Steinways have a nylon sleeve instead of felt. The nylon seems to wear out quickly, so I only use good grade key bushing cloth when re-felting  these pedals. Cut a strip of bushing cloth, put some VJ lube on the area of wear, and tighten the plate back onto the pedal.

 

Of all the pianos I work on, the Steinways are my favourite for repairing the pedals. The above procedure can’t take much more than five minutes. I carry strips of bushing cloth precut to fit Steinway pedals in my tool case to speed this repair even more. However, if the pedals are accessible from the bottom of the lyre, the lyre must of course be removed. Before turning the lyre upside down, take the three pedal rods out and lay them somewhere in order. There is nothing like getting the pedal rods mixed up for wasting time and effort! Unscrew the lyre box bottom, marking it if needed to reinstall it properly. The most common type of system used in this kind of a lyre is where the pedal pin slides inside a wooden dowel. Again, before removing, number these dowels to insure that they don’t get mixed up. Also, check to see if the exposed ends of the dowels are level with the lyre box. If not, they may become noisy. Glue shims onto the dowel to bring it up level. Rebush the dowel if needed, and lube with VJ lube. After reinstalling the pedals, check to see whether they have proper clearance in the pedal slot. Cloth balance rail punchings can be used to adjust the pedal right or left as needed. Note that the felt trim in the pedal slot is not meant to guide the pedals.

 

I remember years ago working on my first lyre like this. I didn’t have the foresight to number the dowels before I removed them. Neither did I pay much attention to the fact that the holes in the dowels were not centred, but rather off-set along the length of the dowel. I reinstalled the pedals, put the lyre back on the piano, and then I checked to see how good a job I had done! One pedal which had the dowels wrong end in didn’t even work! Another one scraped against the pedal slot. The third worked, but it was tilting! If you figure up six dowels times six possible slots for them to go in, the total number of possibilities is thirty-six. I spent quite some time changing these dowels around until I got the pedals to work again.

 

Check the pins on the pedals to see if they have been bent. This often hap pens with an over-zealous male pianist. Straighten this pin or else replace it. Examine the pedal cushions, replacing them if they are worn or hard. Screw the pedal box bottom back onto the lyre, making sure that each screw is quite snug. Check the pedal rod contact point at the back of the pedals. On some pianos the rod has a collar which rides on the pedal. Make sure that it is cushioned by a felt punching. If the rod rides in a hole in the back of the pedal, a piece of leather or rubber must be in the bottom of this hole to eliminate noise.

 

If the pedal rods are brass, use metal polish to shine them up. This helps cut down on noise. For plated rods, check to see if the plating is pitted. Polish these as well. Is the felt bushing in the pedal rod guide worn? Or more commonly with new pianos, is the felt hard from excessive glue? Rebush if necessary. Set the lyre aside.

 

Now we come to part two, lubricating and re-leathering the trapwork. The first step is to pull all of the hinge pins, removing the levers. The pins should be cleaned, polished, and coated with a light film of VJ lube. While the levers are out, tighten any screws on the bearing blocks. Clean and lube these blocks as well. Clean and lube any springs. If the pitmans slide inside a felt bushing, remove them. For brass pitmans, clean them, and polish with a metal polish. I prefer not to lubricate the brass pitmans. If wooden pitmans are used, take a graphite stick and burnish the entire pitman. Do not use any other lubricant.

 

Examine the trapwork levers. Are the holes which the hinge pins go through enlarged? What condition is the leather in? When the leather has worn, I like to replace it with a new piece. Sole leather, as used in shoes, is the best for this purpose. I buy the thickest I can get. It is easy to sand it down thinner if need be. I dislike seeing more than one piece of leather used. Have you ever seen a piano which does not have an adjustable pedal rod? After many years of playing, the original leather at the sustain pedal lever had a hole worn in it from the constant impact of the rod. I have seen backcheck leather, old hammer trimmings, back rail felt, and even felt punchings glued in place to take up the lost motion! For these pianos I not only remove the old leather and glue on new, but I replace the pedal rod with one of the adjustable type. This makes adjusting the rod length much easier, but more important, the top of the rod which impacts the leather is much bigger than the rod itself. This keeps the leather from having a hole punched into it over many years of playing.

 

As a nice finish to step no41, I would like to state my views on how the pedals and trapwork look. Especially if the piano is in the shop for major rebuilding, I like to paint the trapwork and underside of the piano. Flat black is best. The customer may never see this other than when the piano is moved back into their home. But what a nice impression it makes! Similarly, I like to have all of the metal re-plated on the piano. Not only should the pedals be re-plated, but also the pedal rods, casters, hinges and screws. This may cost a little, but in the long run it is well worth it.




Grand Regulation – part XXVI

Step no39: Adjust Key Stop Rail

  

This step is certainly one of lesser importance, although it cannot be overlooked. The key stop rail has, in my opinion, two functions. The primary function, though rarely needed, is to keep the keys from falling off the key pins when the piano is put on its side to be moved. Therefore, the key stop rail should be so adjusted that it is close enough to the keys to keep them from coming off the key pins when moved, with perhaps a little bit of play (maybe 1 /16” or so) between the tops of the keys and the bottom of the key stop rail. This amount of play should be checked on the black keys, as they will be a little higher than the white keys. If the piano is never going to be moved, it is certainly acceptable, possibly even smart with foresight, to remove the key stop rail altogether. This will eliminate problems associated with function number two.

 

Opposed to function number one, which is rarely used during the life of a normal home piano, function number two seems to crop its ugly head all too often. That is, to cause grief to piano technicians! The key stop rail is forever causing wasted time in removing it and reinstalling it. It often interferes with the other action parts. The screws which hold the rail in place become loose and rattle on the keys below, sometimes even causing the keys to stick. This rail must always be removed to retrieve foreign objects which have been caught between the keys, or when making adjustments in the key height or key dip.

 

The regulating technician must be very careful when installing this rail. Putting the rail too low causes it to bind on the keys, making the hammer line rise while throwing off the key level. On some pianos, the rail cannot be too high or the keys in the middle of the keyboard under the locking mechanism will bounce up and cause a noise when they hit the bottom of the lock! I have also seen cases where the key stop rail was too high, letting the sharps come up to high on the rebound. The back of the sharp hits the front of the fallboard and creates a knocking sound that is a hard one to track down.

 

The list of griefs that this rail can cause seems to get longer every year. Pencils, pens, pins, toothpicks, hairpins, etc. all too often get lodged between the key stop rail and the keys. I particularly dislike having to buy a special tool and to carry it with me just to unscrew the rails with the little brass nuts. And once the slotted brass nuts have been removed and the rail taken off, invariable one of the unslotted brass nuts which holds the rail in place from the bottom is so frozen that I can not get it off the threaded rod! Everyone seems to have their little pet peeves about something. Surely, one of mine is the key stop rail.

 

Section V: The Dampers and Pedals

Whenever I have attended or given a class on grand regulation, the dampers, sostenuto, trapwork and pedals are always last on the presentation. There never seems to be enough time devoted to these items, sometimes having to be eliminated altogether because of the lack of time. Since time and space is not a factor here, we will be discussing these last eleven steps in great detail. The order in which these last steps is taken is not nearly as important in section V as it was in earlier sections. However, I have tried to establish a sequence that is easy for me to follow.

This sequence will be:

40) Adjust sustain pedal rod length and stop

41) Rebush / lube pedals and trapwork

42) Check damper guide rail, ease or rebush

43) Check damper lift from key (1/2 dip)

44) Check damper lift from lifter rail

45) Adjust damper stop rail

46) Check string level/damper seating

47) Check sostenuto tabs for evenness, adjust knife angle

48) Adjust sostenuto knife in / out and up / down

49) Adjust shift pedal rod length and stop screw

50) Adjust strike point, tune, voice.

 

Step no40: Adjust sustain pedal stop and length

Because the leather and felt involved in lifting the dampers compacts and wears with use, the sustain pedal rod gets too much play in it. Therefore, on adjustable rods, the rod length must be increased to compensate for this wear. This is fairly straightforward in that the adjustable cap is usually held in place with a lock nut. Simply loosen the lock nut, adjust the rod length to the proper amount, and retighten the lock nut. The correct amount of play in the sustain pedal should be about 1/8 inch. This will allow the dampers to have a small amount of slack in their downward movement as they seat onto a moving string. Less than 1/8 inch can cause the dampers not to function as fast as is possible, while more than 1/8 inch will cause the sustain pedal to have too much play, being an irritant to the pianist.

 

When making this adjustment, I like to remove the action so that I can see that there is a slight amount of space left between the damper lift rail and the bottom of the damper levers. Without taking this precaution to look to make sure that there is space on every damper lever, it is possible to feel that there is 1/8” lost motion, by feeling the pedal as it goes down, but to have one or two dampers  which are lifting too early, causing them to “leak”.

 

Since the damper levers should all lift uniformly from the damper rail, if the sustain pedal rod length is adjusted without checking how the dampers lift from the rail, it may be necessary to readjust the sustain pedal rod length after adjusting the damper lift from the lifter rail. By visually confirming that the damper lift from the rail is correct while adjusting the sustain pedal rod length, you can kill two birds with one stone. If the damper lift from the rail is correct, you can skip over step no44 when you get to that point in the checklist. You can also adjust it again, if the damper lift from the rail is not even, it would be wise to skip step no40 until the damper levers have been regulated.

 

One note that I would like to add concerning adjusting the rod length on Yamaha grands. The factory inserts a leather washer between the lock nut and the adjustable portion of the rod. Why they do this I don’t know. The best lock is to tighten two metal pieces together, so I always remove this leather washer. If the piano is of the type where the sustain pedal rod is not adjustable, a piece of leather of the correct thickness has to be glued onto the sustaining pedal lever. For this reason I always carry an assorted supply of scrap pieces of leather of different thicknesses. Before gluing a piece of leather onto the pedal lever, make sure that some other means of adjustment is not available.

 

Once the rod length is adjusted, check to make sure that the stop mechanism for the downward movement of the sustain pedal is correct. On most pianos, this stop is on the bottom of the keybed. It can be a piece of felt, or even a capstan. Some manufacturers have put this stop in the pedal box. Wherever it is, find it and make sure that the sustain pedal stop is working correctly. Never should the sustain pedal lift the damper levers so far as to engage the damper stop rail. Although we will cover the damper stop rail as step no45, the function of this rail is not to be the stop for the sustain pedal. There should be another means whereby the downward movement of the sustain pedal is inhibited before the damper levers engage the damper stop rail. In the next post, we will proceed with how to repair the pedals and trapwork including the proper lubrication of these parts.

Grand Regulation – part XXV

Step number 38. Check gram weight resistance all 88 keys (continued) 

 

The proper method to check the gram weight resistance of the keys is to either block up the dampers if the action is in the piano, or to remove the action to a bench. All repairs and regulations should have been performed to the action mechanism. I like to start at one end of the keyboard, say at A#1, and work up chromatically doing the downweight measurement on every key.

 

On a typical grand, the proper downweight should be somewhere in the mid 50’s for the lowest notes gradually decreasing to the upper 40’s for the top notes. If the downweight for a specific key is within an acceptable range, like 54 grams for note number 10 in the bass, I’ll pass over that key without making any chalk marks on it. If the downweight is something more like 60 grams, I’ll chalk exactly that number on that key. Once all of the downweight measurements are taken, I do the same for upweight. Again, chalking only those  keys which are out of range. The proper upweight should be 25 to 30 grams less than the downweight. That is, if the downweight was 50, the proper upweight should be 20-25. With a little practice, taking these measurements goes rather quickly. My system is to mark downweight behind the key buttons, upweight in front of the buttons. When finished, all keys out of the proper range can be analysed at a glance. Try to be very accurate when taking these readings. Rarely should a key be chalked for a wrong downweight without also showing something wrong with the upweight, and vice versa.

 

All measurements should be taken to the nearest gram. Using the downweight as an example, the key may not go down at all with 49 grams of weight, but when another gram is added, the key goes down very slowly. A light tapping on the keyframe to aid the key in going down. is acceptable. Record the downweight for this key as being 50 grams. Likewise, in doing the upweight, the key at the point of escapement may not come up with 26 grams of weight on it. But taking one gram off, the key may rise slowly. A record of 25 for the upweight is correct for this key.

 

All measurements should be taken to the nearest gram. Using the downweight as an example, the key may not go down at all with 49 grams of weight, but when another gram is added, the key goes down very slowly. A light tapping on the keyframe to aid the key in going down is acceptable. Record the downweight for this key as being 50 grams. Likewise, in doing the upweight, the key at the point of escapement may not come up with 26 grams of weight on it. But taking one gram off, the key may rise slowly. A record of 25 for the upweight is correct for this key.

 

To illustrate what readings are possible, let us take five sample keys and list their down and upweight measurements:

D         U         F         W

Key 1 50       23       13.5    36.5

Key 2 60       12       24       36

Key 3 45       27       9          36

Key 4 60       35       12.5    47.5

Key 5 43       18       12.5    20.5 

 

Remember that the down and upweight measurements must be used in an equation to find the actual frictional and weight resistances. The equations are F = (D-U)/2 and W = (D+U)/2. However, the experienced technician can look at the down and upweight measurements and without computing the frictional and weight resistances, know what is going on.

 

Key number 1 is about ideal. The key is in the treble portion of the piano and should have a downweight of near 50, which it does. The upweight should be around 25-30 grams less than the downweight, which it is at 23 grams. Key number 2 has measurements which increase the spread between the down and upweights. Notice that the frictional resistance is about double while the weight resistance is the same. Somewhere in this key is an extreme amount of excess friction. Key number three’s measurements go in the opposite direction from key number two’s relative to the ideal key number one. Here again the weight resistance is the same as key number one, but the friction is considerably less. This could be caused by very worn action parts, especially action centres. These two problems, keys number 2 and 3, are frequently encountered in actions.

 

Keys number 4 and 5 on the other hand have about the same friction factor as key number one, while the weight resistance has been changed. It would be a safe assumption that key number 4 has had lead removed from the front of the key (or even worse, added to the back giving more mass to the entire key). Key number 5 probably had jiffy leads added to the front of the key, hoping to give the action a lighter touch. Unfortunately, adding or subtracting lead from the keys does not work like many people think it should. Key number 4 with greater weight resistance will be very tiring to play. If the piano is an upright and more lead was added to make it play like a grand action, the keys will require more pressure to play, but the action will still not feel like a grand action! Key number 5 will be easier to play than key number 1, but it will not repeat as fast, since there is now more weight at the front of the key. Be careful not to get trapped into adding or removing leads to make an action “lighter” or “heavier”.

 

Notice how the down and upweight figures for keys four and five differ from key 1. More weight resistance can be seen with both the down and the upweight measurements increasing relative to key number 1. Less weight resistance can be seen with both the down and the upweights decreasing

 

Assuming that the weight resistance has not been changed in the action, or if it has been changed, the technician has restored it back to the original specs, he will now only have to deal with frictional resistance. Possible places in the action to cause wrong frictional readings are limited, and therefore fairly easy to troubleshoot and correct. 1) The key bushings at the front and centre rails

2) The key hole at the centre rail

3) The hammershank centre

4) The whippen centre

5) The balancier / knuckle contact

6) The capstan / whippen felt contact I have listed the possibilities in the order that I would troubleshoot the action.

Most of the time we will be eliminating friction, especially if all needed repairs such as rebushing the keys, easing the key centre hole, re-pinning loose action centres, polishing the capstans, re-graphiting the balancier, and rounding the knuckles and whippen felt would have been performed prior to checking the gram weight resistance. What the technician will be doing in step #38 is finding those areas which were borderline and hard to pick up earlier in the checklist, or in the case of a new piano, just making sure that everything is playing as well as can be. 

 

Overlooking too tight key bushings, which would give a gram weight reading for the downweight so high as to be impossible to measure, some ballpark  figure can be given as how much the other areas of friction will affect the measurements. The hammershank centre is in my opinion the most important aspect of performing this procedure. For each swing too tight or too loose of the hammershank centre, we can expect about one gram of frictional resistance to show up. This centre is very noticeable to a concert artist, and any unevenness here is sure to bring a complaint. For example, if the hammershank centre is swinging two times instead of eight, the artist will experience six grams more downweight on that key than what he should!

 

The whippen centre is a little less important, but should not be overlooked. A tight whippen centre can give maybe 1-2 grams greater frictional resistance. Perhaps another 1-2 grams less frictional resistance can be obtained by polishing the capstans and burnishing the balancier / knuckle contact point if these were overlooked before. Notice that the jack centre is not a part of this step. Although it definitely affects the way the action plays, the jack centre is a performing part only during escapement and repetition, which are areas beyond where we can check with the gram weights. Likewise with the damper system.

 

A few words should be said concerning the auxiliary whippen springs found on some actions. I can not say that I like them. If they were so useful, more actions would have them, and the actions which do have them should have them on all 88 keys, which they do not! The idea here on why they exist is that the spring tension can be weakened or strengthened to help keep the downweight of the action uniform. In my opinion, this is just like adding or sub tracting a small lead weight from the keys. The problem of each key not having the same downweight is caused by frictional changes. To try to correct unequal friction by adding or subtracting lead or by making a spring weaker or stronger is dead wrong.

 

In closing, when a customer still complains that the action is too heavy or too loose after performing step number 38, make sure that he/she is not used to a piano of a different size, type or make. Also, check to see if the room acoustics have changed, or if the voicing needs to be different. I have even had complaints from older people that an action I thought to be a little light seemed to them to be too heavy. This I attributed to the age of the person, having weaker fingers!   

Grand Regulation – part XXIV

Step 38, Check gram weight resistance all 88 keys

 

Step 38 in the 50-point checklist is to use gram weights to help find too little or too much resistance at the key, something the pianist will surely complain about if overlooked. Unfortunately, many technicians do overlook this very important step when regulating an action.

 

There are two aspects to this step. Through the use of gram weights one can find problems with the lead weighting of the keys, or more frequently, one can find problems with the frictional resistance in the action. Since a fair amount of confusion can result when talking about both aspects, I will attempt to separate the two.

 

The weight resistance in a grand action can be defined as the equation W= (D+U)/2. Where W is the weight resistance of the action as felt by a pianist at the key, D is the downweight pressure of the key measured in grams. The frictional resistance can be defined as the equation F = (DxU)/2. Where F is the friction resistance of the action. How we actually take the down and upweight measurements will be postponed until later. Right now the important thing is to realize the difference between the two concepts.

 

The weight resistance in an action is the result of the front half of the key having to lift the hammer/shank assembly, the whippen, and the back half of the key. This of course includes any lead weights which have been added to the keys. It does not include lifting any part of the damper assembly. Nor does it include the amount of force needed to push the action through the escapement. Rather, it is the force needed to push the key at rest down to the point of escapement. All measurements are taken with the action in the piano with the dampers blocked up, or with the action out of the piano on a bench. Once the keys have been weighted at the factory, this weight resistance is fairly well established for the life of the piano. It does change a little as the hammers wear and need reshaping, causing them to lose a little weight. But this slight variance can be reestablished when the hammers are replaced, assuming the replacement hammers are the same weight as the original. So, for all practical purposes, if the factory did a good job when the keys were leaded, the regulating technician should not have to worry about the weight resistance of the action. In rare cases, the weighting of the keys may need to be altered slightly. This will be covered later.

 

The frictional resistance of the action, on the other hand, seems to continually change and is the source of many complaints for the technician. This friction comes from the key pins, the key centre hole, the capstan, the hammer and whippen centres, and the knuckle balancier contact point. Notice that the jack and balancier centres are not included, as they can not be measured by using gram weights at the key.

 

All too frequently a technician tries to solve a friction related problem by adding or subtracting lead weights. Of course, this is entirely wrong, and can lead to greater problems. The regulating technician should also be aware that complaints of an action being too light or too heavy can have sources other than those mentioned above. To illustrate this, I would like to relate a true story about a concert grand at a nearby university.

 

A well known concert artist hand picked a 9’ grand at the factory, and it was sent to this university. Some of the faculty began to complain that the action felt heavy, while others complained it was too light. The piano was equipped with teflon bushings, which became tight when the piano was shipped to Utah, a dry climate. This caused the action to feel too heavy. On the other hand, the factory had hardened the hammers with lacquer, and with time the hammers became too hard, giving the complaint of an action that is too light.

 

The technician in charge of the instrument decided to replace the hammers, using a duplicate set from one of the supply houses. These ‘hammers were too soft, especially for a concert grand. The teflon bushings were never serviced, as the technician did not know how. Plus he had heard from the factory that they were not subject to changes in humidity (which is not true), being “permanently free”. The piano now had too soft hammers and too tight hammer centres. Naturally the complaint was heard that the action was too heavy. So the technician lacquered the hammers, from the strike point down!

 

The piano now had poor tone, but considerably more power. The reaction from the faculty was favourable since this made the action to feel lighter. That is, until the strings started to break from being hit by too hard of a hammer. Somewhere the technician had heard that if a piano kept breaking strings, the left-off could be made to be farther from the strings. This eliminated the string breakage problem, but now the faculty complained the action was too light and again had no power.

 

This time he decided to remove key leads from the front half of the keys to make the action heavier, and to increase the blow and dip to give it more power. The men on the faculty then complained of poor repetition, caused by the increased blow and dip, while the women complained the action was too heavy, since the front key leads had been removed. The technician reasoned that the repetition springs needed to be strengthened to give better repetition. For the women he regulated the dampers to lift from the keys later making the action to feel less heavy. During all of this, which took a few years, the knuckles began to flatten out. This caused the action to feel too heavy when going through the escapement.

 

The same concert artist who had hand picked this instrument when it was new came back to town to perform upon it. He disliked it so much that he swore it wasn’t the same piano and refused to play on it! Small wonder, isn’t it? The moral of the story is that a concert level technician must totally understand how an action works, and must be able to distinguish what the pianist is complaining about versus what is really wrong with the piano.

 

Before starting to think about using gram weights to find excess friction, and most certainly before trying to reweight the keys, a technician must repair and regulate the action as well as is possible. It should also be tuned and voiced for the room that it is going to be played in. If the action has had lead weights installed (usually jiffy leads) or key weights removed (a hole in the key can be seen), restore the key weighting back to what the factory had it. Only after checking out every possible cause of too light or heavy an action should a technician think about reweighting the keys.

 

Following the 50-point checklist up to step 38 will mean that all needed repairs and regulations necessary to the action have been performed. The only things left are the dampers and trapwork mechanisms. To check the gram weight resistance a technician must acquire a set of gram weights. All of the supply houses carry them. However, do not assume that the individual weights actually weigh what they say on them. Take your weights to a super market or drug store and use their scales to make sure.

 

All measurements must be taken at the same place on each key for uniformity, so I like to place the gram weights directly over the front key pins. I prefer to measure all of the downweights first, then all of the upweights. Chalk marks are made on the keys which are not in an acceptable range. Next week, we will discuss what these measurements mean, and how to correct friction and weight resistance problems.


Grand Regulation – part XXIII

Step 37 – The Repetition String Strength 

 

Next step on the 50-point checklist is number 37, adjusting the repetition spring strength. What we want is to have the springs adjusted as strong as possible, without the pianist feeling it work at the key. This allows the repetition lever to support the knuckle after the hammer is released from the backcheck,.and enables the jack to return to its rest position as fast as possible. Note that during the actual playing of the piano action, the hammer does not rise in order to let the jack get back to its position.

 

This is just the way that we think it happens, since that is the way we see it while regulating the repetition spring strength. What really happens is that the whippen drops, while the balancier supports the knuckle, leaving room for the jack to get back to its rest position. Step 36 just previously performed was regulating the backcheck distance. Other than a very minor effect that the jack height has on the repetition spring, the backcheck distance is the only thing which affects the regulation of the repetition springs. This is why the backchecks and the repetition springs are always regulated as a pair, and in that order. A special note should be made, however, concerning the drop screw. If for some reason the drop screw is adjusted too far down, there will appear to be no rise in the hammer while checking for the correct repetition spring tension. The repetition spring will still do its job, but no rise will be seen. The balancier can not raise since the drop screw inhibits that rise. If this phenomenon occurs while regulating, simply raise the drop screw a little.

 

It is interesting that the repetition spring affects the drop as well as the drop affecting the repetition springs. If the strength of the springs is too weak, the drop will appear to be too great. Raising the drop screw will do nothing to eliminate this problem, since the cause is with the repetition spring tension (see part XVII). Besides this little interaction with the drop, the repetition springs mainly affect the jack height, indirectly affecting the hammer line. And at that, it only comes into play if the repetition springs are not strong enough. As long as the springs have enough or too much tension, regulating the spring strength for all practical purposes affects no other regulation step. This is why I like to save the repetition springs until last when regulating Section IV of the 50-point checklist. As long as when starting you make sure that the repetition springs are strong enough, the other six steps (jack height, blow, let-off, drop, drip, and backcheck) can be perfectly regulated without fear of changing anything by adjusting the tension on the repetition springs!

 

We already know that the springs should be as strong as possible. This is to insure good speed of repetition. Also important is to have all 88 springs to be under the same amount of tension. This will give evenness of touch throughout the keyboard. Believe it or not, if some springs are stronger than others, the pianist can feel this in the resistance at the key! The manner in which I adjust the repetition springs is to remove the action out onto my lap, the front of the keyframe resting upon my legs, the rear still sitting on the keybed. Starting at A1 and working up one key at a time, I gently depress the key enabling the hammer to go through escapement and into check. Then I slowly release the key and watch the hammer rise. If the rise of the hammer is felt at the key, I immediately know that the spring is adjusted too strong. If it is not felt at the key, I watch the speed at which it rises. The speed should of course be as fast as is possible, and uniform throughout the keyboard, yet without any noticeable feel in the key. Although it may appear that the repetition spring strength is either too strong, too weak, or even just right, be aware that other factors can influence the speed at which the hammer rises when released from check:

 

1) Watch out for adjacent knuckles rubbing. This causes the appearance of a spring which is too weak. To correct, raise the hammer all the way until the shank is vertical. Holding the shank firmly to keep from ruining the centre, file off some of the side of the knuckle with sandpaper. You may need to do this a little to each of the knuckles on the sides that rub.

 

2) Check for hammer centres that are too loose or too tight. A too loose centre will give the appearance of a too strong repetition spring. A too tight centre will appear the opposite. If there is any question whether the centre is correct or not, remove the shank and flange assembly and give it the “swing” test. This is a must for evenness of touch.

 

3) Another possibility is that the backcheck is incorrectly regulated. If the backcheck distance is too far from the string, it may give the appearance of a repetition spring which is too strong. The further from the string that the hammer checks, the more the balancier compresses. When the hammer is released from check, this greater compression may show up in a faster rise of the hammer. To correct, simply bend the backchecks to the desired distance, making sure that all 88 hammers check evenly. A checking distance of too close to the string will of course give the opposite effect. However, it is rare that the hammer will check too close and still function properly. This situation usually causes the hammer tail to rub on the backcheck on the way up or to bounce the hammer back to the string, not even going into check.

 

4) Again, if the repetition spring appears to be weak, it may be caused by the hammer tail rubbing on an adjacent hammer head. To correct, either align and square the hammers to the strings, travel the shanks, or taper the tail.

 

5) Lastly, on Steinway style repetition springs, an appearance of too weak a spring is often caused by dirt in the repetition spring groove and on the tip of the spring itself. Cleaning this groove and the tip of the spring was step number 22 on the 50-point checklist. Sometimes the repetition spring was not returned to its correct position in the groove. If it rests outside this slot, it can give the appearance of too strong spring. To check to see if this is the case, gently press sideways on the spring and watch to see if it slips into the groove or not.

 

While we are discussing Steinway style repetition springs, let us also touch on how to adjust them. (See drawing below). To release the spring, I take one hand and hold the balancier up, sometimes bending it away from the others a little to get access to the spring. With the Steinway regulating tool I grab the spring near point A and pulling it down and out I release it from under the balancier. Then I reposition the tool at point B to hold the spring still and to insure that I do not alter the inner windings of the spring, which will affect how the jack works. With my finger at the tip of the spring, I put a very slight amount of pressure on the point B to increase the tension. The tool again grabs the spring at point A and holding the balancier with the other hand I slip the spring back into its slot. The tension of the spring is tested by releasing the hammer from the check and watching the speed of rise.

 

If too much tension exists, the spring is ever so carefully adjusted with the tool at point B. I position the tool under the spring so that I can give it a slight upward movement. By flexing the spring at point B it is possible to weaken it. Experience is the best teacher. Do not alter the bend in the spring at point A to weaken or strengthen the Steinway style repetition springs.

 

In closing, a few words should be said about the Aeolian style brass screw adjustment for the repetition springs. Just like the brass drop screws, the repetition spring adjustment screws also become frozen. Zap them, or judiciously apply a drop of WD40 to them. If someone tried to turn them without realizing they were frozen, the screw heads are often butchered up so bad as to make it impossible to turn them with a screwdriver. To these I just apply a pair of pliers to turn them.






Grand Regulation – part XXII

Step 36 - The Backcheck  Distance (continued)

 

Last month we talked about roughing in the hammer tails and regulating the backcheck bevel. Now we’ll get to the real meat of the subject and cover how to regulate the backcheck distance, along with some pitfalls to watch out for. Going back to the band regulation chart, we see that the key height and key dip directly affect the backcheck distance. An argument can be made that the escapement also affects the backchecking in that if the escapement if set so high that the hammer blocks upon the string, it interferes with the checking. That argument aside, just the key height and dip need be considered.

 

This seems reasonable since the backchecks are connected to the back of the keys. The keys act as a lever, and certainly changes in the height of the lever at the center, or the amount that the lever goes down at the front will change what happens at the back of the lever. The key height should at this point be correct, as it was regulated as step 12 in the 50-point checklist. However, the key dip may or may not have been regulated for the final time, depending upon the sequence used in section IV The Touch part of the checklist. The sequence used here lists the dip as step 35, the step performed just prior to the backcheck distance. So in this order, we can safely set the backcheck distance without worrying about something changing it as other steps are performed. Keep in mind that the backcheck distance may vary slightly, if the key dip is altered, so if the dip is regulated after the backchecks, some touching up of the checking distance may be needed. This only takes a few minutes, and really is not that hard to do. As was mentioned before, use your fingers when bending the backcheck wires, to insure that the wires bend at the bottom, keeping the bevel the same.

 

Again looking at the grand regulation chart we see that the backchecks affect only one other step, that being the repetition spring strength. This is sort of stretching the facts if we say that the backcheck distance actually affect the repetition springs. What happens, is that it affects the test that techniques use to determine the repetition spring strength. If the backchecks are altered to check a little closer to the strings, when the hammer is put into check and then released, the repetition springs will seem a little less strong. Without changing the spring strength, if we then alter the backchecks so that they check farther from the strings, it will appear as we watch the hammer rise from check that the repetition springs have been strengthened.

 

This is caused by the amount that the repetition lever has been compressed. This phenomenon does not normally interfere with action regulating as the repetition springs are always regulated after the backcheck distance. But it can be important during the diagnostic, price estimating stage of the game. To an unaware technician, the first time he looks at an action he may find that the repetition springs are either too weak or perhaps too strong. He may prematurely judge the action as needing the repetition springs adjusted, when in fact something else may be causing the problem. Perhaps the backchecks are way out of regulation. Even more likely is the chance that the action centres are too tight or too loose. On Steinway style actions the repetition springs groove may be dirty and clogged.

 

To help prevent this, keep in mind the following rule of thumb. A good ballpark measurement for correct backchecking distance is to have a hammer in check to be about 2/3 the blow distance above the hammers at rest. Theoretically speaking, the ideal is to have the hammers check as close as is possible to the strings. This will of course give the fastest repetition. But under no circumstances, especially during a hard blow to the key, must the backchecks interfere with the hammer tails as the hammer rises to the strings. To get both good checking without interference will almost always result in hammers checking 2/3 the blow distance above the hammers at rest. Now this can be eyeballed with pretty good accuracy with a little experience. Just watch the colouring on the shoulders of the hammers as compared to the tips of the hammers at rest.

 

The manner in which I like to regulate the backcheck distance is to pull the action out and place it on a level surface. Remember that I usually regulate at the piano, so the workshop bench will not be available. If the customer allows, I cover the lid of the piano with a moving pad and place the action on top of the piano. Otherwise, I may use a nearby counter top, or if nothing else, I just place the action in my lap while seated at the piano. Taking keys that are a perfect fourth distance from each other, I set these as samples doing one section of the action at a time. I use a machinist rule with a sliding pocket clip. The clip is adjusted to mark off 2/3 the blow distance.

 

The sample hammers are put into check and the height at which they check above the hammers at rest is measured. The backchecks are bent with the fingers until all of the samples are checking at the correct distance. At this time the action is reinstalled back into the piano. The sample hammers  are tested for reliability and evenness. If changes are needed, they are made now. The action is removed and the remainder of the backchecks are regulated in that section. Take note that the checking distance may not have to be the same for each section. In fact, if the hammers can check a little closer to the string in the treble, which is usually possible, it will give a little faster repetition, which is certainly desirable.

 

After all 88 keys have been regulated, perform the following tests:


1) With the action out, place one hand about two inches above the hammers at rest. Give each key a good hard test blow with the other hand. If the backchecks are rubbing even the slightest on the hammer tails as the hammer rises, this must be corrected. Either the backcheck bevel is incorrect or the checking distance is too close to the strings. In rare instances, the curvature of the tail is at fault. A good guide to the proper backcheck bevel is for the hammer to always catch, either on a soft or forte blow. When in check, a technician should be able to push the tail down into the backcheck about 1/4” further, but not all of the way through. The only exception is on a very pianissimo blow, where the strength of the repetition spring may keep the hammer from check altogether. If the piano is to be tuned immediately after regulating, I often combined this step with my tuning. I like to “pound” my tuning in, and if I notice that the backchecks are interfering, I’ll correct it then.


2) With both hands, depress groups of keys chromatically to see if they all check evenly. I normally use one hand on the sharp keys, the other on the naturals.


3) If the dip was regulated after the backchecks, recheck the hammers for correct checking distance. Touch up as is necessary.


4) Play each key softly and watch the hammers go into check. The performance here is very important. If the hammers refuse to stay in check, see if the tails need to be roughed up a little. Otherwise, watch for worn backcheck leather. If the hammer appears to bounce away from the backchecks, recheck the repetition spring tension for too much strength, or perhaps the bevel is incorrect.


5) When all is finished and the piano is put back together, if one or two backchecks are misbehaving, they sometimes can be pushed in or out a little with a long screwdriver.

 

Grand Regulation – part XXI

Step 36 - The Backcheck Distance 

 

I would first like to review some of the concepts previously stated before we discuss step 36 of the 50-point checklist. The seven main steps in part IV The Touch section of the checklist can vary as to the order in which they are performed. Six of these seven steps are always regulated in pairs, forming four groups:

 

I.              Jack height / blow  distance

II.            Let-off / drop

III.           Backcheck distance / repetition spring strength

IV.          Aftertouch

 

The 50-point checklist gives only one sequence that these four groups can make. That order is I., II., IV. & III. This particular sequence eliminates having to reregulate the backchecks after setting the dip. However, it is only usable if the repetition springs are strong enough to support the hammers. If they are not, then the sequence should be changed to something like Ill., I., Il. & IV.

 

Sometimes the escapement is maladjusted so high that the hammers will not let-off. This causes the hammers to bounce on top of the jacks, the tails never coming close to going into check. In such cases, the escapement must be regulated first, giving a possible order of Ii., Ill., I,, & IV. Technicians who prefer the Dip Priority method of regulation may choose an order of IV., I,, II., & III, So it is plain to see from the examples given here that depending upon the circumstances, each of the four groups could be placed first in the sequence.

 

Aligning and squaring the backchecks to the hammer tails was step 30 in the checklist. This is essential before trying to regulate the backcheck distance. The hammer tails must also have been roughed up a little to insure that the wood of the hammer tail will get caught by the leather of the backcheck. Let me digress a little and explain how to do this. If the hammers have not been replaced, but the tails need to be roughed up a little, I take a piece of wood which has at least two flat surfaces forming a right angle. The right angle should be so positioned that the bottom flat surface is resting on the tops of the hammer shanks. The shanks are of course supported from underneath to keep them level.

 

Raising one hammer at a time, the other flat surface is brought next to the shank and held there as tight as is possible with one hand. This keeps the shank from moving from side to side eliminating possible damage to the action centres while the tail is being roughed up. With the other hand I use a small file made out of wood about 118” thick by 1” by 6” with coarse grit sandpaper glued to the wood. The file is gently moved across the tail being sure to keep the curvature of the tail the same as it was. 

 

The above procedure has two very important points. Number one, the curvature of the tail is essential to good backchecking. This will be covered in detail later. Number two, I prefer to use sandpaper to rough up the hammer tails. Others have been known to use coarse files, moto-tool saw blades, or not to rough the tails at all! lncidentally, this is not limited to the technicians in the field, as a ,number of factories are guilty of these practices. Moto-tool saws and coarse files often make the tails too rough. In no time they have eaten away at the leather on the backchecks.

 

This residue leather gets on top of the hammers and into the grooves as the hammers wear. It makes a different sound! The leather particles also cling onto the damper felt and strings, creating problems there as well as wearing out the backchecks prematurely. The practice of making the tails too rough seems to be a relatively recent problem. Perhaps it has come about because fine quality buckskin has not been available to manufacturers and the tails had to be rougher to catch on the cowhide. Whatever the reason, two wrongs do not make a right, it makes a mess!

 

When I find a piano where the tails are too rough, I always spend a few extra minutes and sand them down a little. If possible, I try to replace the cowhide backchecks with top quality buckskin.

 

If the piano needs new hammers, DO NOT order the tails pre-shaped and roughed if at all possible. All too frequently when the duplicator performs this task, he overdoes it! The curvature of the tails is too great and they have been over-tapered and over-roughed. As I have stated before, I like to order my hammers unbored and untapered. The hammers are bored to suit the individual piano requirements. The tails I sand also to suit the particular piano. I do this on a belt and disc sander in my shop. The procedure I use is as follows:

 

1) Bore all 88 hammers.

 

2) Hammer 88 is fitted to its shank and tested in the piano for the correct placement to give the proper striking point.

 

3) The side of the tails are tapered by hand on the disc sander. Using good judgement, good eyesight, and a little practice, the results are uniform and professional looking.

 

4) Find an old grand hammer shank and taper it at the tip to enable the shank to pass quickly into the hole on the hammer moldings. Don’t overdo the amount of taper. Wrap masking tape around the hammer shank to give the same distance from the centre pin of the shank to the middle of the hammer molding as was needed for the test not no88.

 

5) Hold the flange of this old shank stationary while passing the hammer tails one at a time across the disc sander. This performs three jobs at once!

 

A)   It roughs up the tails with the proper grit of sandpaper so that they are neither too rough but yet rough enough.

 

B)   By holding the flange as I rotate the shank / hammer assembly across the disc sander I also give the tail the proper curvature. The tail is sanded to exactly match the arc that the hammer has. When a tail sanded in this manner catches the leather of the backcheck, it has the maximum contact area possible, giving faultless checking.

 

C)   Passing the shank into the hole of the hammer positions the tail at the same angle against the disc sander as it will have against the backcheck. This presands the bass and tenor hammers at the correct angle.

 

6) All 88 hammers are glued to the shanks. Great care is taken to insure that the tails as well as the hammer tops are aligned perfectly. No further work is needed on the tails once they are glued on. This eliminates all possibilities of damage to the action centers as a result of filing the tails after the hammers have been glued on. It is also quicker and certainly better in that the tail curvature is the optimum rather than a close approximation.

 

Getting back to step 36, the first task is to make sure that the backcheck bevel is correct. Once the revel has been set, the checking distance can be easily regulated by bending the backcheck wires, Whether adjusting the wires for the correct bevel or for the correct backcheck distance, I prefer to use my fingers rather than an expensive tool! Reason 1 is that I haven’t got any more room in my tool case for another tool! Reason 2 is that by using my fingers I bend the wires at the key, thereby keeping the bevel correct once it has been adjusted. Seldom is the need by the way, to adjust the bevel, but I wanted to mention it for those times when incorrect bevel is the problem.

 

In case you are not familiar with the term bevel, it is the angle of the head of the backcheck, in its forward/backward position. Simply stated, too much bevel causes the hammer tail too high, many times wearing the leather prematurely. In extreme cases too much bevel can cause the hammer not to catch at all, bouncing the hammer back towards the strings. Too little bevel (the backcheck is almost vertical) causes the hammer not to catch too far from the strings. In extreme cases, the hammer passes on by the backcheck, compressing the repetition lever until the repetition spring throws the hammer back upwards. This is very bad and can easily be felt at the key by the piano player.

Grand Regulation - part XX

Step 35 - The Aftertouch (continued)

 

 

We left off last week with how to set the aftertouch on the natural keys, and some of the problems which occur when trying to set the dip with a key dip block. I just want to emphasize how much I dislike using a key dip block. As stated before, when beginning to regulate, only one measurement is needed, either the blow distance or the key dip. Remember the ‘Dip and Blow Priority’ discussion? The arguments are clearly in favour of using the Blow Priority method where possible. I find it no problem when finished regulating to alter the action to give it a little more power or a little faster repetition to suit the artist. All of this can be performed without a key dip block!

 

 

Now that the natural aftertouch has been established, virtually a repeat is done to regulate the sharp aftertouch. Taking a section at a time, watch the amount that the hammer rises after drop and add or subtract punchings so that the sharps have the same amount of hammer rise as the naturals. Greater care must be exercised when raising a sharp to avoid elongating the centre hole in the key. Double check the evenness of the sharps in the down position by depressing a group of them and comparing their heights to the neighbouring naturals. Correct the offending key height, blow, let-off, drop, or jack alignment and reset the aftertouch. Continue to the next section until all 88 keys have been completed. Now turn all of the paper punchings under the felt punchings, preferably keeping the large cardboard at the bottom and the thinnest paper at the top.

 

 

Regulating the sharps in this manner eliminates all of the mess and confusion of how to set the sharp key dip. No more need to use a coin beside the sharps or using an expensive tool which is too small to handle, or trying to feel the backs of the sharps versus the naturals. The method as explained here accomplishes the same thing as regulating the sharps to raise the same amount at the capstan as the naturals. This is what is really wanted, so that both the long and the short keys perform the same lifting motion at the whippen. This is the only way that the entire keyboard will play uniformly. I hasten to add though that watching the hammer rise after drop is far easier than trying to feel the level of the capstans with the keys in the depressed state. Number one, the capstans are curved and difficult to feel if they are even; number two, the capstans are inaccessible unless the top action is removed, which only requires adding weights to duplicate the weight just removed!

 

 

 

In my opinion, the term aftertouch is the most misunderstood term in grand regulation. I never cease to be amazed at the many different definitions this term is given by otherwise knowledgeable technicians. Even after teaching classes on this subject, I have had technicians come up to me afterwards and start talking about something completely foreign to the term, yet they understood it as aftertouch! Here are some of the definitions I have heard:

 

1)    Raising the capstans is synonymous with setting the aftertouch.

2)    Leveling the keyboard, especially by putting a crown in the middle is to give the action “aftertouch”!

3)    Adjusting the amount of let-off as regulating the aftertouch.

4)    The amount of travel that the jack has away from the knuckle has been defined as aftertouch. [Perhaps this is correct, but it is certainly foreign to the standard definition.)

5)    The compression of the felt punching being called the after-touch.

 

And so on, with some ideas being so far off, it isn’t funny.

 

 

Once the correct meaning of the word has been established, I have been even more amazed at what technicians think is the correct amount of aftertouch. Some say it varies with the size and use of the piano. I agree somewhat, but I have heard them include the statement that a concert grand should have more aftertouch to please the artist. This is the exact opposite of what is true. Trying to get a specific measurement for the aftertouch is like trying to get blood out of a turnip. Some say “set it at what feels right”. Somewhat vague to say the least. Others claim that aftertouch should be almost non existent. One technician said that the aftertouch should take up the last third of the key dip!

 

 

Let me first state that I do not believe that there is one and only one correct measurement for aftertouch. As I will explain later, the aftertouch can even be tapered throughout the 88 notes on the keyboard. Last month I gave as an illustration a measurement of 0.025”. For normal, everyday pianos which have gone through the break-in period, I’ll use this figure. For a new piano or an old one which has just been restored with new action parts, I prefer a little more aftertouch. This will allow for the normal compacting and settling of the new parts. Be aware though, that I regulate these pianos as usual and only when completely finished I give it more aftertouch by raising the hammer line slightly. Never should the punchings be taken out just to give a new piano more of a safety factor.

 

 

By slightly raising the hammer line I am counteracting what I know will soon happen. Because the knuckle flattens, the whippen felt compacts a little, the felt punching at the center rail compresses slightly, the hammer line will fall and the shanks will end up resting on the rest rail or whippen cushion felt. If a home piano should have about 0.025” aftertouch, should the concert grand be given more? Think about how often these two pianos are serviced, and why a safety factor is given to the key dip. The home piano may get tuned once a year, or if you are lucky, maybe twice or even three times. But the concert grand may be serviced once a week, or as often as once a day! If the climate changes from dry to moist and the action swells, or if the piano has really been played a lot and starts to compact, you’ll be able to regulate the concert piano as these changes occur, but not the piano in the home.

 

 

More important is the speed of repetition available to the concert artist. The less the key dip, the faster the repetition. No wonder that the concert pianos where the technician thought they needed more aftertouch play like a truck instead of a Ferarri. Unless the artist expresses his preference differently, I regulate concert grands to have the minimum amount of aftertouch.

 

 

On the other hand, is there a maximum amount of acceptable aftertouch? Number one, if a soft blow is given to the key and the hammer tail is not caught by the backcheck, the hammer can rise so high from excessive aftertouch that it touches the strings. Please note that a similar situation will occur if the repetition springs are too strong, so don’t decrease the aftertouch without assessing the problem. A second reason why excessive aftertouch is undesirable has to do with the jack tender. Too much key dip forces   the jack between the let-off button and the jack stop felt. Especially on an older piano where the glue is weaker, this can cause the glue joint to break. The tender then will not trip the jack and a blocking hammer will result.

 

 

Going back to the idea of a tapered aftertouch, the let-off was tapered wider in the bass and narrower in the treble. To compensate for this, either the hammer line must also be tapered, the aftertouch must be tapered, or both. If the choice is to have the same amount of aftertouch for all 88 keys, then the hammer line is tapered approximately the same as the let-off. I prefer somewhere in between, tapering the aftertouch as well as the hammer line.

 

 

Since the speed of repetition is dependent upon the key dip, a little less dip in the higher treble will give a slightly quicker repetition. The artists like this, because they play fast, light passages in the high treble which often demand a very fast repetition, while in the bass the artists often play harder to create a larger tone. The deeper after touch in the bass will feel better to them. 

Grand Regulation - part XIX

Step 35 - The Aftertouch (continued)

 

The aftertouch is purposely regulated late in section IV, “The Touch,” because so many other steps affect it. In fact, I often do the backchecks and repetition springs before regulating the aftertouch (sometimes this is a must if the springs were weak), making the dip the last of the nine essential steps in grand regulation. Regulating the dip after the backchecks may throw the backchecking distance off, so some minor touch-up may be necessary here. The amount that the key goes down in the front directly affects the amount that the key goes up at the back, thereby changing the height at which the backchecks catch the hammer tails.

 

Make sure that the key height and blow distances are very even, as just a little mistake in either will show up in too much or not enough aftertouch. The action should have been played upon and “settled in.” This is especially true, if the keyframe has been refelted. If nothing else, give the piano a good tuning, making sure to “pound the notes in.” After playing, recheck the key height, using both a straight-edge as well as eyesight, even looking at the keys from different angles. Likewise for the hammer line. All corrections should be made before starting to regulate the aftertouch.

 

The action must be in the piano, as it is impossible to work with such close tolerances with the keyframe away from the keybed. The keyframe should have been bedded to the keybed. Doublecheck this. Install action hold-down springs at both ends of the keyframe or else screw down the keyblocks. Be careful that there is not too much pressure being exerted by the keyblocks upon the keyframe. Too much pressure causes the middle of the keyframe to bow up, giving a false reading of not enough aftertouch. Too little pressure can cause a similar false reading on keyframes like Steinway, which have a slight upwards bow at the ends. Both would cause noise when the action is played.

 

Getting the feeling that a lot of checking and double checking is taking place? Failure to double check the work previously done can often lead to a lot of lost time, having to redo work which was not properly completed. Regulating the aftertouch is one of many places I use to recheck the work already performed. The method I use is to set the dip on the naturals (white keys) first, then I regulate the sharps (black keys) to match the naturals. With my thumb under the front of the keys to keep them from going down too fast, I depress one key at a time with my finder and watch the hammer as it approaches the strings. As the key is depressed, I watch for six different things:

1. Feel the weight resistance of the key. Is this key’s resistance more or less than the neighbouring keys?

2. At 1/2 the key dip, is the damper starting to lift from the back of the key? This can be felt at the key as well as seen from above.

3. Near the let-off point, is the hammer to string alignment correct?

4. At the point of let-off, is the let-off distance correct?

5. Watching the hammer fall from the point of let-off, is the drop distance correct?

6. And lastly, after the hammer drops, does it rise back up again towards the strings? It should rise about 1/8” as the key reaches a fully depressed condition.

 

The last step, watching the hammer rise after it drops, is what I define as aftertouch. It directly shows that the key has a little safety factor in its downward movement after escapement. This safety factor is very important. Not only does it insure that the action will complete its escapement cycle, it also allows for the action to swell a little during a moist season of the year and still be playable. Over many seasons it allows for the normal wear and compaction that takes place.

 

Even though the term aftertouch implies something happening with the key, I prefer to regulate the aftertouch by watching the amount that the hammer rises rather than the amount that the key goes down. Why? Think about the hammer to key ratio. With the key dip at about 3/8”, the hammer blow distance is about five times the key dip, or around 1 7/8”. Taking a reasonable figure of 0.025” for aftertouch in the key, this would be compared to the hammer rising after drop about five times 0.025”, or 1/8”. I find it to be much more accurate to try to measure 1/8” compared to 0.025”. If I do mismeasure, a small error in working with the amount that the hammer rises is negligible, whereas a small amount in the key can mean a lot.

 

Regulating one section of the action at a time, I depress each natural key and watch this rise of the hammer. Doing this in rapid succession increases the accuracy of trying to regulate all of the keys in a section to have a similar amount of aftertouch. I go over each section twice, once to get them close, the second time for fine regulation. The first time through, I watch only the hammer rise. If a key needs to have punchings added or subtracted, I gently lift it up at the front, being careful not to lift the key too far and elongate the hole at the centre of the key. If punchings need to be taken out, lift the felt punching with a pair of tweezers and remove it. Subtract at least the amount that is needed and reinstall the felt punching. If too much was removed, it will be OK. If punchings needed to be added, or if too much was taken out when subtracting, put the proper amount of paper punchings on top of the felt punching. At this stage of the game, if every key has paper punchings on top of the felt punchings, that is ideal.

 

Now go through the same section the second time, this is the fine regulation. Depress each key in rapid succession, trying to find any which are not uniform to the others. Then, depressing a group of four to five keys at a time with one hand, feel the tops of the keys with the other hand. This is similar to regulating the key height, but now the keys are in the depressed condition. Doesn’t it make sense that the keys should be perfectly level in both the up and the down position? If any keys are felt to be at a different level than the rest, go searching for the reason. Something is not correct in the rest of the regulation steps previously performed.

 

We know that the aftertouch is correct, so the first place to look is with the key in the up position. If the key is level to its neighbours in the up position, but not level in the down position, check the blow, let-off, drop, and jack alignment to the knuckle. It might be that all four of these are a little off. More likely, or rather for easier trouble-shooting, just one of them may be the problem. Whatever the cause, correct it, and readjust the punchings so that the correct aftertouch is restored, then recheck the key again in the down position. It is ideal to have all 52 natural keys to be level in the up and down position as well as having uniform aftertouch.

 

Notice that I never once used a key dip block. This is by far the most accurate method of setting the dip, for it directly achieves the results that a key dip block is supposed to give but often does not. The way I regulate uses aftertouch as the means of evaluating whether the entire action has been well regulated. The other method of setting the dip with a key dip block and seeing whether or not aftertouch exists is nowhere near as accurate a method.

 

I have asked many technicians who regulate the key dip block method how they use aftertouch in their regulating process. Most tell me that they just check to see, if aftertouch is present, a sort of proving-out of the regulation process. Never are they concerned with the amount of aftertouch or whether it is consistent from note to note, but only with the fact that some aftertouch is present. Watching the amount that the hammer rises after drop is unimportant. Yet I have seen their finished product. Some keys have way too much aftertouch. Others right next to them may have barely enough to complete the escapement cycle. These technicians can’t seem to figure out why an artist complains that the action isn’t uniform, when the tuner had just spent hours “regulating” the piano.

To be continued next week.

Grand Regulation - part XVIII

35)  The Aftertouch


Apparently not everyone understood what I wanted to communicate about regulating by the dip or blow priority methods. Whether a technician chooses one method or the other, the results will be the same. Some piano technicians get the impression that depending upon whether the dip priority or the blow priority was used, the regulation would come out different. This is not the case. When regulating by the dip priority method, the technician must regulate completely a few sample keys to prove out by aftertouch that the distances for the dip and blow will work. Likewise when regulating by blow priority method. I have stated in the past why I like to use the blow priority method. These reasons will be restated, along with some new ones concerning the use of a key dip block.

 

Referring back to the grand regulation chart printed in the After Touch post, only two steps affect the blow distance while five steps affect the dip. Of these steps, the key height affects both the dip and the blow. Regulating the key height was step no12 in the 50-point checklist, so it should not interfere when getting to section IV The Touch at step no31. This leaves only the jack height to affect the blow distance, while four steps still affect the dip. These four are the blow, jack alignment, let-off, and the drop. Remember that I always include the correct aftertouch measurement when discussing the dip.

 

What we want as the end result is uniform aftertouch across the entire keyboard. I find it faster and easier to use the blow priority method to obtain a uniform aftertouch. The fact that the jack height alone affects the blow distance while four steps still affect the dip is certainly one reason why I prefer to use the blow priority method However, the dislike which I have for using a key dip block is by far the main reason. I would like to relate some of my experiences when trying to use a key dip block.

 

Given the choice between playing on a keyboard with plastic keytops versus one with real ivory and ebony, most musicians will quickly choose the ivory/ebony. This is especially true for performing artists. Their hands perspire while playing, and the ivory/ebony keyboard absorbs this moisture while the plastic does not. When performing very fast passages, this can make the difference between playing the correct notes or slipping and hitting the wrong notes.

 

Unfortunately, ivory keytops present a problem to the regulating technician. Amongst its other attributes such as discolouring, cracking, chipping, coming unglued, ivory also has a tendency to warp and to wear. On instruments where the ivories have been played upon so much that the keys have become grooved, or where the sides of the keytops have begun to warp up, I find it impossible to accurately set the dip with the use of a key dip block. Replacing these old ivories is not always possible, as the customer often would prefer these to plastic. Yet it is impossible to determine whether to add or subtract punchings using a dip block!

 

Another somewhat related problem is where the keytops have been replaced, but the job was less than desirable. Everybody has seen such a piano. The keytops moved a little when the clamp was put on and the tops of the key itself were not sanded level. The keys cannot be levelled or squared properly. Yet the customer cannot afford to replace the keytops again. But they would like the action to be in better regulation! Try setting the dip on such a keyboard with a dip block! The same situation occurs when the key buttons are very worn but the customer can’t afford to have the keys rebushed. The only way to get the action regulated is to use the blow priority method.

 

Being a concert technician, I can recall many times receiving a phone call to come out and tune for a concert. When inquiring about what else the piano may need,  the response is always “all it needs is to be tuned”. When you hear that, you just as well had plan on spending the whole day at that piano! What the people are saying is that all the care it has had in years is tuning. The action needs regulating, the hammers are worn and need voicing very badly, action centres need repairing, etc. More than once, I have been told by the performing artist to either get the piano in concert condition by show time, or else he will cancel the performance! With only a few hours to work and so much to do, should time be taken to get the keys perfectly level? If not, then how can you give the artist the uniform aftertouch you know that he will demand? The answer is to use the blow priority method.

 

Going to the other side of the coin, what about the times when you have sufficient money to do everything the piano needs, and enough time to do the work? We have all experienced the elusive compression of the front rail punching. When checking the dip with a key dip block, it is certainly possible to read the same key as shallow, deep, and just right depending upon how hard the key is depressed. The Yamaha instructors had a good solution to this problem. Listen to the notes as you depress the keys. If the piano is producing the same volume each time the dip block is used, chances are that you are depressing the keys with the same force each time. It is also very helpful to go quickly from one key to the next. They even explained how in the Yamaha factory the workers used the sides of their fingers instead of the bottoms because the fingers are more sensitive there. Unfortunately, as is the case with all good ideas, there is the exception to the rule. What do you do, if the piano needs  voicing? The dip should be set before the instrument is voiced, but the sound from the piano cannot be used to determine if the block is depressed each time with the same amount of force!

 

In spite of all the above reasons for using the blow priority method, there is one more reason which in my opinion takes the cake. Even if the above problems could be overlooked, this last one is enough in itself. We all know that different size pianos have different lengths of keys. I am speaking about white keys in particular. A spinet has very short keys while a concert grand may have keys that are 50% longer. The length of the key of course determines the leverage that the pianist has. I believe that this difference in key length is one of the main reasons why pianos cannot have the same amount of key dip.

 

I cannot understand why the piano supply houses sell us only one type of key dip blocks. Because the keys are different in length, the angle that we use a key dip block  varies with the size of piano. A spinet has a much sharper angle than a concert grand in the depressed position. Why then are we left to using the same dip block for both pianos? When comparing the adjacent keytop with a dip block, if the angle of the key does not match the angle of the block, it is very easy to read the dip as being shallow, correct, or too deep depending upon where the block and key are compared!

 

The workers in the piano factories are aware of this problem. They take a dip block which is too thick and gradually sand it down to match the angle of the keys for the piano which they are working on. This is fine for working in a factory where the number of different lengths of keys are rather small. The technician just keeps a dip block handy for each model of piano he works on. But, what about the technicians in the field? We work on hundreds of different pianos. Shall we clutter up our tool cases with a different dip block for each of these pianos? Or, would it be easier and faster to just eliminate the dip block by regulating the blow priority method? Next week, we will discuss how to set the correct dip by aftertouch on both the naturals and the sharps.