Grand Regulation In Detail - Part 8

In part VII of the series on grand regulation we discussed the two methods of regulation for grands, the Dip and Blow Priority. Now that we know the differences between these two methods, two decisions must be made before Section IV ‘The Touch’ can be begun. The first decision is what procedure to use to accomplish the regulation process. The other decision, depending upon which Priority method was chosen, is to determine the correct measurement for the dip or blow. Once these two decisions have been made, the remainder is a piece of cake. Without these two decisions, regulation becomes a long, hard task with lots of wasted time.

Let us look at some of the many grand regulation procedures that are available to choose from. This list is by no means all inclusive, and just because a certain procedure has been omitted from this list does not infer anything about its relative merits and value to us. 

 

The five procedures listed on the left are Dip Priority, the five on the right are Blow Priority. In viewing this chart you will notice that some procedures have more steps than others. But pay more attention to the order in which these steps are listed. For instance, in procedure no10 the whippens are aligned to the knuckles as step number three. But in step number seven the hammers are aligned to the strings, making realignment of the whippens necessary. Other procedures listed have similar mistakes. I would certainly modify the order of some of these procedures to eliminate such needless doubling back. 

 

If you were to regulate an action, which of these procedures would you choose? Should you select the one that is from the factory manual for the brand of piano being worked upon? If so, then each time you regulated a different brand of piano you would use a different procedure! Needless to say, this is awkward. Or should you select a procedure written by your favourite author to use on all brands of pianos? Chances are that your author’s procedure is different from what the manufacturer calls for, and may not be as detailed as the factory manual. As an example, some pianos have an auxiliary whippen spring. If you did not know this, and the procedure you were using doesn’t mention it, you would probably overlook it. Well then, should you select the procedure that is the most detailed? I don’t believe so. Just because it has 125 steps doesn’t mean that it is better than one with 50 steps!

How do you decide upon a procedure? Obviously, you want the one which is easiest and fastest for you. People differ in their abilities and knowledge. What works best for one technician may be awkward for another. I suggest that everyone make up their own procedure to suit their own needs. In creating your own, remember that the order of steps must be logical so that the minimum of doubling back occurs.

As a help here, consult the Grand Regulation Chart which appeared in the 2nd post of this series on grand regulation. Naturally, you will want to include those steps such as reshaping hammers and rebushing keys that are normally done when regulating an action. Every step should be in a convenient order to go along with how you regulate. Do you bench regulate or do you regulate at the piano, or a little of each? In that case, you have to create your own procedure. 

 

Now that the procedure has been decided upon, next is to decide what measurement to use for the ...

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Grand Regulation In Detail - Part 7

Last discussed in the 50-point guide to grand regulation were the two main methods to regulate. One is called the Blow Priority method, the other is the Dip Priority. To determine whether a given procedure is Dip or Blow Priority, just look to see which of the two is regulated first in the order of steps listed. Once the dip or blow has been adjusted, all of the other action regulations are then set based upon this first measurement.

To explain this further, there are seven main steps in section IV, The Touch portion of the 50-point checklist These seven are: 1) Blow, 2) Dip, 3) Let-off, 4) Drop, 5) Backcheck distance, 6) Repetition strength, and 9) Jack Height to the balancier. Again, as in the past, the dip includes the correct aftertouch measurement. Let us take the example of a Blow Priority system first. If the repetition spring is strong enough to support the hammer first adjust the jack height in order to insure that as the blow is set that the hammers will always return to the same setting. Step two then would be to set the predetermined blow distance.

Depending upon how worn the whippen felt is, how flattened the knuckle has become, and how much the hammer has been filed the capstan will need to be raised further to compensate for greater wear in order to achieve the desired blow distance.

Raising or lowering the capstan affects directly or indirectly all of the remaining steps. Raising the capstan raises the whippen assembly, which causes the jack tender to become closer to the let-off button, and the balancier to become closer to the bottom of the drop screw. Once the let-off and drop are correctly set, changing the capstan will necessitate readjusting the let-off and drop. If the correct after-touch is to be achieved, the dip measurement is predetermined by the blow and let-off distances selected. The amount of dip will affect the backcheck angle. And, as we all should know, we set the repetition spring strength based upon the hammer’s release from the backcheck. So out of the seven main steps in section IV TheTouch, changing the capstan will affect one way or another all seven steps: To eliminate any unnecessary doubling back to reregulate a step already performed, set the blow distance right in the first place, and all of the other six steps will come out correct the first time through.

Remember the “circle of five steps” as explained in the first article of our series on grand regulation? If not, please look again at our first post. This illustration helps to show how each step affects the others.

 

Adding the let-off and drop in between the blow and the dip completes the circle with all seven steps. Of these seven, only two can be places of compromise to compensate for action wear. The let-off, drop, backcheck distance, repetition spring strength, and jack height can only be regulated to specific tolerances or distances, with very little room for variation. Only the dip and blow can compensate for action wear. The Dip and Blow Priority methods are the means of setting one of these variables in the beginning, making any compromises needed with the other variable latter.

One school of thought amongst piano technicians is that the dip is not a variable. In other words, there is a specific measurement that the key is supposed to go down, that measurement being standard throughout the world, and no variation from that measurement (usually 3/8”) is acceptable. This of course leaves only the blow distance as a means of compromise as the action wears. I believe this school of thought to be a little narrow minded. There are times when the dip should be altered a little. When I say a little, I mean within + or - .036” at the maximum. Next week, we will discuss just how “‘standard” this measurement is.

We have already discussed what the main areas of wear are: 1) ...

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Grand Regulation In Detail - Part 6

Section III. Alignments

29) Align jack to knuckle core

In order for the power to be transmitted from the whippen to the hammershank efficiently, the jack must be properly aligned under the knuckle. 

Looking at the action sideways, the rear of the jack (the surface towards the hammer) should line up perfectly with the rear of the knuckle core. Normally, this alignment is easy to see. The knuckle should be glued on perpendicular to the shank, and if the hammer is new and was bored correctly, the shank should be perpendicular to the jack. Sighting along the rear of the jack, it should be easy to tell when the jack is in line with the knuckle core.

However, if the shank is not perpendicular to the jack this alignment is hard to see. Two things can cause this:

A. The hammer has worn resulting in the capstan being turned up to keep the blow distance close enough. The shank then becomes more than 90 degrees from the rear of the jack. In such cases, imagine a line drawn from the rear of the knuckle core down to the point on the knuckle leather where the jack would touch it. Then line up the rear of the jack to this point.

B. The other reason, which is fairly common, is that the hammer hole was not placed correctly in the molding. This results in the top of the hammer, either, being too high, or too low in relation to a line drawn down the middle of the hammershank.

Boring the hammer wrong of course results in the shank not being perpendicular to the jack as in cause A. If this angle of the shank to the jack becomes too great, then either the hammer has worn excessively so that it should be replaced, or if the hammers are new, then the hole in the molding should be plugged and rebored.

Why was the hammer bored incorrectly? Have you ever noticed when regulating the hammer-blow distance, that when the tops of the hammers are adjusted so they all are, say, 1 3/4” from the strings at rest, that the hammers in each section vary as to their heights measured from the keybed to the top of the hammers?

We should expect the bass hammers to be higher since the bass strings are higher so they can cross over the tenor strings. But notice that if the agraffes are not the same height as the capo d’astro, the hammers will also vary in their heights between these sections.

If the original or duplicate hammers were not bored taking into account these different string heights, then the hammershanks will not be perpendicular to the jacks with the hammers at rest.

We will discuss this problem further in a later post on hammers, but let me add here that some pianos have a different string height for each section!

An easy way to align all of the jacks is to align the end hammers in each section, and then by using a straightedge or a thread, align the jacks in the respective sections to the end samples.

Note that some manufacturers mark a line on top of the balanciers. This line serves as a guide only when  ...

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Grand Regulation In Detail - Part 5

Section III. Alignments

27) Align hammers to strings

 

To facilitate this alignment procedure, install the action into the piano andmake a rough check of the let-off measurement. If the let-off is very far from the strings, the hammer-to-string alignment will be very hard to make. So try adjusting the let-off by say one-half or one complete turn of the adjusting screw and see what number of turns it takes to get the hammer to let-off right next to the string.

 

At this point in the regulation procedure, if the hammer blocks on the string, it will be all the easier to make the alignment. Then remove the action and turn all of the let-off screws the number of turns that you found necessary to get the hammer closer to the strings.

 

Before starting to centre the hammer to the strings, make sure that the hammers have been filed, removing all traces of former string grooves. If the piano has agraffes, then your job will only be to align the hammers to the strings. If the piano does not have string aligning mechanisms throughout, then you must make sure that the strings are properly spaced and centred before attempting to align any hammers.

 

Normally, unless the plate has been repositioned or a bridge reglued onto the soundboard, there should be a straight line running from the hitch pin through the bridge pins and on to the tuning pin hole in the plate. The middle string of a trichord should run along this line, with the right and left strings having the same inward pointing angle, since the bridge pins are wider spaced than the spacing at the V bar.

 

Begin aligning the hammers to the strings by taking a wire hook and coming down from the strings, lifting the shank so that the hammer blocks on the string. Or, take a finger and lift the bottom of the whippen taking the hammer past let-off and pushing up until the hammer again blocks on the string. I prefer the latter method since the wire hook is slower and can cause the hammer to be pulled to one side if you are not careful.

 

Looking directly above the hammer, check to see, if it is properly centred to the strings. For a trichord, equal amounts of hammer should be seen on both sides of the unison. On single or double unisons, the hammer can either be likewise centred, or they can favour the bass side a little, depending upon how you want the hammer to strike when using the una corda pedal.

Any hammers which are properly centred on the strings, I mark with an “O” on the key with a piece of chalk. Those which are off to one side, l mark with a straight line on the key to the side which they need to go, varying the thickness of the chalk mark as the amount the hammer needs to be moved. Do one section at a time.

Pull the action out after chalking all of the keys, and compare the marks with the way the hammers look. All of the chalk marks must coincide with either a perfectly centred hammer or else a hammer that needs to be traveled, angled, spaced, or a combination of these three.

Place a long screwdriver blade or other object such as a spare pedal rod under all of the shanks in this section and check the hammers first for traveling. Even though a key was marked “O” the hammer may be traveling or have the incorrect angle. After correcting the traveling, heat the shanks of those traveled along with any others whose angle needs to be changed until all of the hammer angles look uniform. Lastly, space the hammer by slightly moving the flange sideways.

If the flanges are of the type where a screwdriver or flange spacer can be used, install the action into the piano and space the flanges directly by lifting up the hammer until it blocks on the string. If the flanges are not of this type, then they must be spaced outside of the piano. Use the width of the chalk marks as a guide to how far to move the flange, and try to use any keys marked with the “O” as a point of departure.

I get two keys about five or six keys apart marked with the “O” and work from these, putting t action back into the piano and making any needed refinements.

Remember that some manufacturers ...

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Grand Regulation In Detail - Part 4

II. THE TOP ACTION (off the keyframe) - continued

22) Clean repetition spring and groove (Steinway, Yamaha, Bosendorfer). On Steinway, Yamaha and the Bosendorfer whippens (which have the butterfly type repetition spring), the spring grooves are coated with a graphite solution. The Yamahas now use a teflon coating here, but the older models of this type whippen are graphite.

Hurray that someone has finally seen the light! This graphite paste becomes dirty and gummy, and makes for a source of friction instead of eliminating it. These grooves in the underside of the balancier and the spring tips must be cleaned in order to achieve a good regulated action. If left uncleaned, the jack height is very hard to set since the repetition spring not only has to support the knuckle, but also has to overcome this messy graphite paste as the balancier moves.

To clean this groove, release all 88 repetition springs from the grooves and turn the action upside down, taking care to protect the hammers while doing so. Run a piece of cloth up and down the grooves until clean. Be careful not to damage the groove. Now choose a lubricant which will, hopefully, eliminate this problem during future use. I have tried three different lubricants for this job, but I have reservations about all three of them. If any of the readers have a sure-fire method to solve this problem, please be kind enough to share it!

I have tried:

1) Dag 154. This is a graphite solution and works well for lubricating the spring. I question whether it will be free from the dirty, gummy mess which plagued this area in the first place.

2) Spray teflon. I feel that this teflon is not as good as what is available to the manufacturers. It does not seem to last. Hence, the repetition spring, while not getting dirty and gummy, will also not be lubricated quite well enough.

3) White grease. This is supposed to prevent rust and corrosion on the spring. It is not absorbed into the wood, but it is bound to get dirty with time. As to whether it will also get gummy and inhibit the spring is anybody’s guess. The ideal would.be to apply a teflon coating like what Yamaha now uses, but to my knowledge this is not available to technicians.

Turn the action right side up and clean the tips of the repetition springs with a suede brush. Rebend the springs back into their grooves, making sure that the spring is indeed in its groove by applying as light sideways motion.

23) Round whippen felt if needed. The cushion felt on the bottom of the whippen which rests upon the capstan always compacts and gets worn from the constant hammering of the capstan hitting against it. Incidentally, this compacting along with the flattening of the knuckle is why a new piano always loses its hammer line. In the case where these parts have only “settled in”, the action can be brought back into regulation by raising the capstans and making the corresponding adjustments in the let-off and drop. Since raising the whippen puts the jack tender closer to the let-off button and the balancier closer to the bottom of the drop screw, these two must be changed.

I use two wear areas, the knuckle and the whippen felt, to decide whether to repair an action or to replace the action parts. Just like a flattened knuckle, a worn whippen cushion felt must be ...

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Grand Regulation In Detail - Part 3

In this third part of our grand regulation guide, we will continue with discussing the Section II, The Top Action. Remember that action centres were discussed last week, so now we will begin by talking about hammer traveling, which is Point 16 on the 50-point checklist.

Point one on the checklist was tightening all of the screws. Now if all of the foreign material was cleaned out from under the flanges, usually by using compressed air, we are now ready to travel the hammers. What we are looking for is a hammer that swings to one side as it is raised from the rest position to normal striking height.

I find it best to use a long rod such as an old pedal rod in traveling a whole section of hammers at one time. Insert the rod under the hammershanks near the hammer, at about the rest felt/rest rail area. Hopefully the rod is long enough so the ends will protrude over into the next section of hammers. If not, make sure the rod rests on at least one shank at each end so as to be level.

 

If any hammers are badly angled (Point 17), I find it easier to correct these first before traveling. On the other hand, if the hammers are traveling way out of alignment, then it might be easier to travel first, angle later. Anyway, keep in mind that a travelled hammer must be angled in order to keep the striking surface square to the string, assuming that the striking surface was square in the first place.

To find hammers that need traveling, lift the rod up and down approximating the hammer-to to string distance and watch for hammers moving towards their neighbours. All hammers should lift vertically, with no sign of movement to the right or left. If necessary, use a square or a board with vertical lines drawn on it as a guide to make sure the hammers all lift perfectly straight. Without the use of a guide it is possible to travel all of the hammers, but end up with them all moving slightly to the right or left. Any horizontal movement will result in a loss of power, abnormal wear on the hammer and its bushing, and voicing problems. Do not bother to travel the hammers any higher than a few inches, since they do not function any higher in the piano.

Any shanks which are moving to the right or left are corrected by placing a thin shim under the flange so the shank will travel vertically. The rule is to place the shim on the side of the flange toward which the hammer is traveling. In other words, if the hammer is moving to the right, place a shim under the right side of the flange. I prefer to take the flange off completely and place a gummed piece of paper such as packing tape or a strip of masking tape as a shim. This works better than just a piece of newspaper so often seen here, since they stay with the flange whenever it is removed in the future.

 

Also, in taking the flange off to shim it, I always check it to see if some foreign material is causing the hammer not to travel correctly. If more than two shims are necessary, filing the flange on the opposite side is preferred to installing many shims. In really bad cases, rebush the centre.

Since shimming the flange actually tilted the hammer, now we need to go back and correct the hammer angle. In case you do not know what I mean by hammer angle, it is correcting those hammers which are leaning to the right or left. Do not confuse this with the angles which the hammers are glued on to so that they are aligned to the string angles. This is in a different plane. The angles we are talking about are caused by the shank warping or by shimming the flange to correctly travel the hammer. To correct the hammer angle, take a heat gun or an alcohol lamp and heat the shank by quickly passing the heat up and down the length of the shank.

At the same time, apply a tilting pressure to the hammer head in the direction it needs to go to correct the angle. You will feel the shank twisting when it gets hot enough. Don’t burn the shank! Keep in mind that some pianos are designed for the hammers to be slightly angled a couple of degrees in certain sections, usually the tenor or bass. Note that if the same rod is used here in angling that was used in traveling, the hammers will all be uniform in height (remember that we have not got to regulation yet) and therefore easier to spot those which are misangled. Do not lightly pass over these two procedures, as they really make a difference when it comes time to voice the piano.

Next on the checklist is Point 18, reshaping the hammers. At some time in the future, we will discuss when to tell if the hammer has enough life left in it to reshape it or if it needs to be replaced. As this post is based mostly on reshaping in the shop, we will also discuss in the future ...

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Grand Regulation In Detail - Part 2

Having discussed section I, The Keys & Keyframe, last week, we will continue with section II, The Top Action. Note that those procedures covered recently elsewhere such as rebushing, steaming warped keys, repairing the balance pin hole, etc., will be skipped over in this guide to regulation.

Also, some procedures were skipped over which were not covered elsewhere, such as refelting the keyframe. These I intend to discuss at a later date. If any reader feels I have neglected or passed by a subject, please let me know.

 

II. THE TOP ACTION (off the keyframe)

15) Check action centres, repin or shrink as needed. There are many tests which can be used to determine if the action centres are too tight or loose. Lets discuss the hammershank / flange centre first, since it’s by far the most important and the most troublesome. I will list the six checks I regularly use for this centre:

A) Wiggle each hammer gently side to side and feel by hand if the centre feels loose. B) Similarly, insert a long screwdriver blade under the shanks and wiggle the blade from side to side. Watch the hammer for any sign of lateral movement. Any movement indicates a loose centre. C) While the screwdriver blade is still under the shanks, lift all of the hammers in a section up and quickly release the blade downwards. Any sluggish centres will be late in following the blade down. D) With the screwdriver still under the shanks, block the blade up at both ends so the shanks rest on the blade, preferably right on top of the rest felts/rest rail area. Individually raise the hammer and let it fall on the screwdriver blade. Listen closely to the sound upon impact, and watch how much bounce the hammer takes. Too little bounce indicates a tight centre. A noisy impact of the shank upon the blade indicates a too loose centre. This noise is much like striking a baseball bat upon the concrete and listening for a crack in the wood. E) With the action firmly in hand (preferably screwed down to the keyframe) put the action on one end and swing the hammers out away from their rest position and back. Any sluggish centres will be noticeable by the lack of movement. F) And, of course, the best method is to unscrew the flange and check the swing of the hammer by hand. Take the flange in one hand and hold it vertical, the hammer being taken by the other hand and raised to a horizontal position, 90” from the flange. Holding the flange very still, release the hammer and watch how many times it swings under the flange. This will look much like a pendulum. Count the number of passes the hammer makes under the flange. For this centre, seven or eight passes is considered excellent. If the piano is a Steinway with teflon bushings, then the best results are at five or six passes. Fewer passes indicate a sluggish centre or a bent centre pin. Greater than eight passes indicates a loose centre or some other problem such as a crack in the shank at the bushing area.

Unscrewing all 88 hammers may seem like a lot of work, but it is the only way to know for sure how every centre is working. If the piano is used for concerts, then plan on taking every hammer off and checking the centres from time to time. This can mean the difference between the artist praising you and the piano for an even and responsive action, or criticism for a piano that has a heavy touch, was uneven, or would not repeat.

This is not as much work as it sounds. Just make sure the hammers are all properly spaced to the strings before you begin, and the whippens and backchecks are aligned to the hammershanks and tails. Take off all of the odd numbered hammers and work on them. Replace them and realign them using the neighbouring hammers and the previously aligned whippens and backchecks. Go on to the even numbered hammers and complete the job in the same manner. Recheck the hammer to string alignment and you are done.

Now let’s talk about repinning action centres.

I highly recommend using a pin vise which is capable of extracting and installing centre pins. If you work on Steinway teflon bushings very much you will notice the extractor pin is a little large and often ruins the teflon bushing while .removing the old pin. Just remove the extractor pin and turn it down, using a drill and wet/dry sandpaper.

While we are discussing Steinways, be sure to ...

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