Grand Regulation In Detail - Part 1

In the last post, we discussed a 50-point checklist to be used in regulating grands. Last month we printed a grand regulation chart which shows how each of the nine regulation steps directly affect the others. Now in combining these two concepts, we will go through each of the 50 points in the checklist and explain in detail to how perform each step.

I. KEYS & KEYFRAME

 

1) TIGHTEN ALL SCREWS, REMOVE ACTION AND KEYS

 

Before anything else is done to piano, all of the screws should be tightened. This includes the screws, case parts, action parts, lyre and damper assembly parts. This is to insure that everything that should be snug and tight is, eliminating any noises or excess wear which could crop up from loose fittings. It also insures all of the moving parts are in correct relationship to each other. When tightening down the plate use a large screwdriver has had the tip ground to fit the plate screw heads. The whole blade should fit the screw head, not just the corners of the blade. I use a Sears 3/8” Craftsman which has a square shank, enabling me use a crescent wrench on the shank to help turn the screw. If this method is used, be sure to put your weight on the screwdriver to keep from ruining the head of the screw. Do not turn plate screws more than ½ turn at a time, and skip every other screw. Otherwise, it is very easy to flex the plate running the risk of possible plate breakage. Do not attempt to change the nose bolts unless something is obviously wrong, such as the bolt coming loose in the beams under the soundboard. Nose bolts are not to be tightened to achieve more downbearing. Tighten all action and case part screws hand tight. Overtightening will only crush the wood or else result in a stripped screw hole. On aluminium action rails, if the hole is stripped, a larger, self-tapping screw will solve the problem. Do use common sense and refrain from tightening screws which are adjustments to action mechanisms. These include the drop, let-off, jack regulating screw, jack stop rail, repetition lever and spring screws, cheekblock adjusting screws, etc.

To tighten the action screws, the action must be removed from inside the piano. Take care not to depress any of the keys when pulling the action out, or a broken hammer shank will result. Place a hand on each end of the keyframe and pull the action out slowly. Now remove the action bracket screws which hold the stack into the keyframe. Some actions have the front screws (nearest the keyboard) slanted at an angle. These are removed first and installed last. Make sure you have some method for returning the action screws back into their original holes. Set the stack aside and remove all 88 keys. To keep from enlarging the balance pin hole on the bottom of the key, take hold of the key at the back as well as the front and lift off evenly.

2) SAND KEYBED, APPLY TALC OR SLIPSPRAY

The ideal match between the keybed and the keyframe is for both to be perfectly straight and level. Otherwise, when the keyframe shifts, high and low spots are sure to occur, resulting in noises. Therefore, sand lightly the keybed to give it a level, smooth surface upon which the keyframe can slide. Also, apply talc, slipspray, or some other substance to help the keyframe shift quickly back and forth. A straightedge may be helpful in finding high/low places.

3) SEAT ACTION ON KEYFRAME, REPAIR STRIPPED SCREW HOLES

 

Seating an action frame is an often overlooked procedure. The keyframe should be straight and flat on its underside to match the keybed. If the action brackets have any amount of space between the bottom of the bracket and the top of the screw hole on the keyframe, a warped keyframe will result when the brackets are screwed down tight. Of course, if any holes are stripped, drill-plug and redrill. Cross-threading the screw holes can be eliminated by starting the screws by hand or by turning the screws backward until it drops into the threads.

 

4) BED KEYFRAME: BACKRAIL, FRONTRAIL, STUDS; SAND AS NECESSARY

 

Now that the stack is on the keyframe without the keys, back up the balance rail bedding screws (make sure you get the ones only visible from underneath on Yamahas) and install the action into the keybed, securing the cheekblocks. The cheekblocks should apply a small amount of pressure to the keyframe to keep it down, but not so much as to cause it to raise in the middle. A perfect fit is when the shift pedal works freely with the keyframe secured on the key keybed. Bed the backrail first, then the front rail, lastly the balancerail studs. The correct specification here is to not have any spaces between any of the three rails at their point of contact with the keybed, both in the regular and in the shift positions. When bedding the front or backrail, tap on the rail and listen for knocking noises. Mark offending areas with chalk. If the knock is at the ends of the front rail, the cheekblocks were not fitted correctly. If the knocks are at the middle of the front rail, try to loosen the cheekblocks to see if they were too tight. If not, then lift the front or backrail up enough to places and paper strips grit side up under the contact points on each side of the chalk marks. Draw the sandpaper out and recheck the area for knocks. Remember that the area to be sanded is not where the chalk marks are, as these are the high places, but rather the low places surrounding the chalk marks. Go slow in the sanding process so as not to sand the keyframe too much, producing more high places. On a badly warped keyframe, one might have to cut out strips on the top of the frame and hammer in hardwood wedges in order to straighten it out (front or back rail only).

Bedding the balance rail can be done by either of two methods. The short method is to take a straightedge over the entire length of the keyframe, spanning the front and back rails over where a stud exists. Turn the stud down until it just touches the straightedge. At this point, the three rails are in a straight line. Do this to every stud, and if the keybed is perfectly flat (which it isn’t) then the keyframe should fit. But since the keybed is not perfect, correct any small differences by installing the keyframe complete with keys and stack into the piano, securing the cheekblocks. Now by lifting gently on the top of the stud, and at the same time knocking lightly with the other hand, adjust the stud so that it makes a knocking noise when the stud is lifted, but is secure with no pressure on the stud. Do this to all of the studs and the keyframe can be considered bedded to the keybed. The other method is with using strips of newspaper. With the keys off the keyframe but with the stack screwed on and cheekblocks secured, slide a strip of newspaper under each of the bedding screws and starting at one end, turn the studs down until friction is felt when the newspaper is pulled gently. Go onto the next stud and turn it down also until resistance is felt. Recheck the first and second studs before going on to the third. Continue the operation remembering to recheck those studs already set until all of the studs are down. Check the front rail to make sure that the studs are not down so far as to raise the front rail and you are finished.

5) ALIGN ACTION RAIL DISTANCE IF NEEDED

 

All piano actions were designed with a specific distance between the middle of the centre pin of the hammer shank to the middle of the center pin on the whippen flange. Most actions have an adjustment on one of the other rail to correct this measurement. Some, like Steinway, are permanently set. However, if this distance is not correct, the action will not play right and is impossible to fine regulate. Contact the manufacturer for the correct specifications for the particular instrument if this appears to be the case.

 

6) REMOVE THE STACK, POLISH KEY PINS, CLEAN KEYFRAME

 

Take the stack back off the keyframe and set it aside. If the punchings and backrail cloth are in good shape, clean with a brush. If not, replace with new felt and cardboard. Clean the key pins or replace if they are pitted. Turn the front rail pins back straight if they were turned before.

 

7) PUT KEYS BACK ON KEYFRAME, CHECK CENTER HOLE FOR LOOSE/TIGHT FIT

 

Return the keys back on the keyframe in the same manner in which they were removed, taking care not to ...

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Grand Regulation - - A Checklist - Part 2

Last week we talked about a 50-point checklist and knowing what changes are taking place during action regulation. A three-question quiz was also given which will be repeated here:

1) Does regulating the jack height to the balancier affect the strength of the repetition spring? 

2) Does regulating the let-off affect the backcheck distance? 

3) Which of the following affect the amount of aftertouch: key height, blow, jack alignment, jack height, let-off, drop, backcheck, repetition spring?

Now that a month has passed to think about the answers, wouldn’t it be great if there were some place to turn to look up the correct answers? How many of us have taken the time to thoroughly investigate and think out what happens in grand action regulating? Everyone should own or have access to a grand action model. These are a great help in trying to figure out a problem or to understand the hows and whys of the working parts.

Here is a grand regulation chart which lists the nine action regulation steps and how they directly affect each other. (You can find the chart at the bottom of my last post. It’s the 2nd graphic.) X’s mark steps which are affected, O’s mark those which are not.

 

It should now be quite easy to find the answers to the quiz. The answer to question no 1 is yes. Think of the butterfly type repetition spring as now used in Bosendorfer, Steinway, and Yamaha grands. As the balancier is raised or lowered to the correct height above the top of the jack, the tension on the repetition spring is changed. Think of the balancier and whippen as opening and closing like a jaw. The tension on the spring increases as the balancier is lowered. However, the effect this style of spring has is the opposite one would expect. Even though the tension increases, the hook of the spring moves forward (toward the keyboard) in the spring slot on the bottom of the balancier. This necessitates the spring tension to be increased in order to achieve the same effect, since the point of contact is now further from the balancier’s flange.

In answer to question no 2, the grand regulation chart is marked no. Now it is possible to argue that if the key is depressed slow enough, as when we regulate the let-off, and if the let-off is changed considerably, that the hammer will check at a different height. True, but the main factor here is not the let-off distance. Rather, the speed at which the key is depressed. In actual playing, the hammer must continue to move upwards after let-off in order to strike the string, then it falls back, going into check Changing the let-off only changes the amount of power that the key gives the hammer. The backcheck distance does change, of course, on whether the player gives the key a hard or soft blow. On a hard blow, the hammer rebounds more forcefully into the check position and ends up a little lower. On a very light blow, the hammer may not even go into check. Anyway, we can be pretty safe if the backchecks are regulated before the let-off, since as can be seen on the grand regulation chart, the backchecks only affect the repetition spring strength.

For the third question, the factors which affect aftertouch are:

1) Key height. Changing the key at the balance rail affects the key at the front rail by a factor of about 1:2. Adding a 0.010 balance rail punching will increase the dip, and hence the aftertouch, by about 0.020.

2) Blow. Piano actions are designed so that the dip to blow ratio is about 1:5. Changing the blow changes the amount of key dip needed for total escapement. When we raise the capstan to lessen the blow distance, the effect of raising the whippen puts the jack tender closer to the letoff button and the end of the balancier closer to the drop screw. This causes escapement to happen sooner in the stroke of the key, giving more aftertouch.

 

3) Jack alignment to the knuckle. Since the jack has a double function of raising the hammer and also causing let-off, regulating the jack to the knuckle changes when the jack tender engages the button. Therefore, if the jack is moved inward, toward the keys, the tender moves down and away from the let-off button, creating escapement later in the dip, meaning less aftertouch.

 

4) Let-off.From what has already been said, it is obvious that let-off directly influences aftertouch. Making the let-off closer to the string creates less aftertouch.

5) Drop.If drop is defined as the amount that the hammer drops after let-off, and that aftertouch is defined as the downward movement of the key after drop, then the amount of drop is proportionate to the amount of aftertouch. Decreasing the amount of drop increases the amount of aftertouch.

Notice that on the grand regulation chart ... 

 

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Grand Regulation - - A Checklist - Part 1

QUIZ

1) Does regulating the jack height to the balancier affect the strength of the repetition spring?

2) Does regulating the let-off affect the backcheck distance?

3) Which of the following affect the amount of after-touch: key height, blow, jack alignment, jack height, let-off, drop, backcheck, repetition spring?

Do you know for certain as a particular grand regulation procedure is performed, how it will affect the other procedures? Or which of the other procedures will alter the regulation just completed? For instance, in the jack to knuckle alignment, changing the jack will alter the let-off and the amount of aftertouch. But if the capstan is changed, the jack will have to be realigned again.

Say that you are about to completely recondition the action of a grand. Do you have an orderly, logical approach figured out so that nothing will be overlooked with a minimal amount of doubling back, wasting time? Action reconditioning can be much simplified by using a thorough, detailed checklist. The advantages are obvious. Most of us cannot take the time to go over an action in one sitting. Interruptions are bound to happen, whether it be for lunch, overnight or for two weeks. Frequently there is a loss of memory as to what has been done, where you are now, and what was next. With a checklist, you need only to mark where you are when the interruption occurs.

Unless grand regulation is something one does frequently, one probably does not have the proper sequence memorised. Manuals are available from the different manufacturers, but none of them give a complete list of things to do. Neither do they agree on the sequence to be used. For instance, one manufacturer says to level the keys and lay the dip first. Whereas another says to regulate the jack, let-off and blow first, and then level the keys and lay the dip. Many more differences can be found, too.

 

In general, are not all grand actions made similar today? Granted, they may have different designs of whippens, action rails, sostenuto systems, etc., but they all have parts working in the same functions (minor exceptions). Therefore, it should be possible to create a checklist to be used on all grand actions. One which has all of the different steps one must go through to properly recondition and regulate in the most efficient and logical way.

 

Here is a 50- point checklist for grands which does just that:

I.Keys & Keyframe

 

(1) Tighten all screws, remove action and keys

(2) Sand keybed, apply talc or slipspray.

(3) Seat action on keyframe, repair stripped screw holes

(4) Bed keyframe, backrail, frontrail, studs; sand as necessary

(5) Align action rail distance if needed (whippen/hammer center pin)

(6) Remove action, polish front and centre rail pins, clean keyframe

(7) Put keys back on frame, check centre hole for loose/tight, correct

(8) Check buttons, ease or rebush as needed

(9) Check keys at frontrail pins, ease or rebush as needed

(10) Clean and buff keytops and fronts

(11) Square keytops, check for war page

(12) Adjust key height and level all 88

(13) Lay dip, at least 0.400 for now (0.450 for Steinway)

(14) Space keys

II. Top Action (off of keyframe)

(15) Check action centers, repin or shrink as needed

(16) Travel hammers

(17) Check hammer angle/shank warpage, correct

(18) Reshape hammers

(19) Regraphite jack top and balancier window

(20) Space jack in window

(21) Round and file knuckles, needle if hard

(22) Clean repetition spring and groove (Steinway, Yamaha, Bosendorfer)

(23) Round whippen felt if needed

(24) Polish capstans

(25) Clean knuckles and backchecks

Ill.Alignments (installation back on keyframe)

(26) Align action frame in piano (adjust keyframe stop block)

(27) Align hammers to strings

(28) Align and square whippens to knuckle

(29) Align jack to knuckle core

(30) Align and square backchecks to hammer tails

 

IV. Touch

 

(31) Jack heigth to the balancier

(32) Blow

(33) Let-off

(34) Drop

(35) Aftertouch

(36) Backcheck distance

(37) Repetition spring

(38) Check gram weight resistance all 88 keys

(39) Adjust key stoprail

V. Dampers and pedals

(40) Lube and releather trapwork

(41) Check damper guide rail, ease or rebush as needed

(42) Check damper lift from key (‘h blow)

(43) Check damper lift from lifter rail

(44) Adjust damper pedal rod length

(45) Adjust damper pedal stop

(46) Adjust damper stoprail

(47) Check string level/damper seating

(46) Sostenuto pedal rod length/ knife angle

(49) Sostenuto assembly (tabs) aligned to knife

(50) Shift pedal rod length and stop screw

A pretty extensive list. I am sure that ...

 

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Hammersmith Odeon / Eventim Apollo - Yamaha CFIII

 

 

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Testing The Tuning Tests

Some of the most useful information to come out of the last years use of the proposed testing procedure is an objective analysis of the skill levels of the testees, a concept of what a good tuning is and some of the most effective tuning evaluation procedures I know of.

If you are in a testing situation, or just wish to be able to perform an analysis of your own work these procedures can be helpful. If you do not have testing equipment and wish to objectively look at your own tuning you will have to do the tuning and then walk away from it for an hour or two to let your mind rest and acquire a new perspective on tuning.

It is of no consequence which fork you use or which “temperament octave” you prefer. The analysis of tempering will require a minimum of twenty-five notes for potential error elimination. The only strictures on this two-octave placement are those imposed by the piano and your ears. The two octaves should not cross over wound strings if at all possible and the range should not be such that the beats of sixths and thirds become too fast for accurate assessment.

For this purpose the biggest or the best is better, but biggest does not necessarily mean the best, so choose an instrument that is easy to tune and fine for listening and all that might imply for you.

Pick almost any notes, high, middle or low and using that note as a pivot point, check the two fourths, the two fifths and especially the two thirds that revolve around that one note and compare them all but in pairs, not mixed. If all appears well with that note and its intervals, then go to the next note above or below and continue this form of analysis until the entire two octaves have been validated and possible changes noted but not necessarily made yet.

As an example, C4 is the pivot note. Listen very carefully to the C4-F4 and G3-C4 fourths several times. What is being sought is a variation of the beat rate that is less than acceptable. Within practical limits, they should be identical. If no change is desired, then switch to the related fifths, C4-G4 and F3-C4, again played several times, seeking improper tempering. It is well to make good use of the third/sixth test of fourths and the sixth/tenth test of fifths to help define beat rates. The more difficult but highly informative conjunctive thirds G#3-C4 and C4-E4 must have the 4 to 5 beat rate ratio. This is one of the more helpful tests in that it has a balance that remains constant and once the ear is attuned to the relationship, a minor error assumes major proportions.

Each octave must be tested three ways. First the third/tenth test will verify the degree of expansion, second ...

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Music Quality Stability Tone Touch Tune Cost Beauty Durability Serviceability

Music is the ultimate goal of the piano, an objective that sometimes gets lost among the tunings, regulations, voicings, etc., etc., etc. At the same time, we must be concerned with the quality and stability of our work and of that of the instruments. Tone, touch and tune are our daily bread, as they are for the musicians, if in somewhat differing manners.

Of great importance to all is cost, beauty and durability, but the final stone in my echelon of priorities is essentially ours and that of the manufacturers or rebuilders: serviceability. In the designing and fabrication of pianos, and during rebuilding, certain practices, procedures and oversights creep in that can have a dramatic effect on one aspect of serviceability - tuneability. The next time you tune a piano that is pleasure to tune, you can be assured that many factors contributed to that quality. Here are listed few of the possible sources of trouble on those pianos that are not as tuneable.

The tuning pins must be round, with a consistent diameter and radius. Poor pins can be too long, too short, out of round, change dimension from pin to pin and from the top to the bottom of the thread. They can be poorly plated, the threads poorly cut, the metal too soft, the holes out of place and too small for the larger gauges, and finally, they may have unsquare tips. The tuning pin may appear to be a very simple piece of metal, but when carefully considered, its complexity emerges to demand our attention.

Tuning pins that are too tight require much effort that could best be used to control the pitch of the strings. These pins leave one with less than the best feel for the block and what the pin is doing in the block. Tuning pins that are too loose lack ease of control, long term durability and stability of the tuning. Pin block materials and construction need not be discussed here except to define our requirements; rigidity, dimensional stability, resilience and durability. If made and installed with care, all else is fulfilled. What is required at the interface of the tuning pin and the pin block is a slightly different matter. Wood and metal should come together with out any other matter at all; no resins, oils, moisture or carbonized wood. Some tall orders, but the factors of greatest importance are the care in drilling the holes and the cleanliness of the pin and the stringer.

I have seen beckets (the part of the string that goes through the tuning pin) so long that they have been wound part way around the tuning pin in the opposite direction by an adjacent pin. This is a little long; the proper length is through the pin but not out the other side. The reasons for this are that overly long beckets make repinning that block difficult in the extreme because the becket will not come out of the pin without destroying the coil. The overly long becket represents a painful hazard to the fingers when moving the tuning hammer and, finally, it looks tacky.

Coils that are not tight against each other leave a pin too high, tend to cause tuning instabilities and lack the beauty of neatness. On the finer gauges, a becket can be pulled out of the hole over a period of time. This is why old piano makers put four and five coils in the treble; also, the holes in the pins were bigger than the holes in present pins. Three coils are sufficient; two and a half are not.

 

Tuning pins that have been left too high present several problems to the tuner, not the least of which is tuning instability. These pins will not twist any less than lowered pins, but the twist can be ...

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Tuning Instability

In speaking to our customers about what causes a piano to go out of tune, the most common subject is the weather. A change in temperature will have little or no effect on the tune of the instrument except that most temperature changes are directly coupled to a change in humidity. Humidity change is the major factor when pianos are tuned two or more times a year.

The next most common factor is string stretch. It takes very little stretch, as we all well know from what a new string does, to make a piano sound horrid. Several years of tunings are needed to get all the stretch out of new strings. The newer pianos seem to go out because of settling of the structure as well as the stretch of the strings, but I have no proof of that.

Time itself, with the changes of weather, string stretch and structure, all cause the tuning to slide downward.

Hard playing and especially hard hammers will knock out the tuning of even the best tuner and the best piano.

One factor that seems to be rather neglected is the degree of sensitivity of the client. Some pianists are on the phone the instant the piano thinks about going out of tune, others can let the instrument go for ten years and not know the difference.

After the piano is settled in and the weather, stretch, age, time and customer demands are compensated for any real problems of the instrument itself can be considered.

One common cause of tuning instability is pinblock-back separation, where the pinblock is being pulled away from the back posts of uprights by the tension of the strings. This is most easily spotted by looking at the top of the assembly or from the bottom of the block. When the sides begin to separate from the back a weak piano plate and back can flex more than planned by the designers; tapping with the knuckles along the side will produce a hollow sound where the glue has failed.

A good number of pianos were produced with aluminium / magnesium plates that over extended periods do not have the rigidity and stamina of cast iron. This is a chronic problem without any real solution for that instrument.

When the smaller pianos were in their developmental stages, many of their unique problems were yet to be solved. One of which was determining the minimum weight and the structural rigidity for long-term integrity. Some of these early instruments tend to be ...

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