GRAND REGULATION - part IV

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 replaced. I find it far less hassle to just replace the whippens and shanks/ flanges instead of taking the time to try to repair these parts. But, if the piano is obsolete or if only a little worn, the whippen felt can be rounded back to its original shape by passing wool yarn through it just like as in rounding aworn knuckle. In the.case where the whippens are obsolete and the cushion felts are deeply grooved, then the only solution is to replace just the whippen felt. I might add, that if such a piano was thrown into my hands, I would try to procrastinate doing the work until the owners junked the piano!

24) Polish the capstans. The top action is still off the keyframe, so the keys are readily accessible. Either buff them on a buffing wheel or if on the job away from the shop, take some chrome/ metal polish along with a rag and polish them a section at a time. Just use a wooden block along the back of the keys to keep them level and from wiggling too much. After polishing, I like to spray the capstans with emralon.

25) Clean knuckles and backchecks. A good shop will have a portable air compressor as a part of the essential equipment. Take the nozzle and blow with high pressure up and down the knuckle and backchecks. Of course, it goes without saying that the entire action should be blown out, but I like to use a higher pressure when cleaning the leather. If the knuckles are dirty with graphite, this must be cleaned off next. Use some sort of a solvent, whatever is available in your area (some say that Renuzit is still available, but I can’t get it). Then take a suede brush and comb the leather. Check the hammer tails. If they are not rough enough to ensure good backchecking, use a hand file and correct. Be careful not to roughen the tails so coarse as to wear the back checks abnormally.

This ends section II. Before proceeding onto section III, make sure that all needed repairs have been finished and that sections I and II were performed accurately. Remember that if two people are working in the shop together, one can do section I while the other works on section II. 

III. ALIGNMENTS (install action back on keyframe)

26) Align action frame in piano (adjust keyframe stop block). The action parts must all line up to insure full power and reliability. Take as samples the action parts to the keys at the ends of each section. Starting at the strings and working down, align the parts to the strings. This is assuming that the strings are in proper alignment. If the piano has been restrung, or especially if the plate has been removed, this may not be the case. Where there are agraffes or some other string positioning devices, you can be pretty sure that the strings are aligned well, assuming the plate is OK. Too many “technicians” try to install pinblocks and soundboards when they do not know how to align them. If you have trouble aligning the action and can see the piano has been “rebuilt,” the problem may be that the piano was not properly rebuilt. Anyway, loosen the hammerflange screw to align the hammer to the string. Next, align the balancier so it is directly underneath the knuckle. This is done by either loosening the whippen screw and tilting the whippen or else shimming the flange and rotating the whippen. More will be said on this subject in step 28.

After the sample keys are aligned, check to see how the hammers look in relation to the strings. If all of the hammers are off to the left (most usually) or off to the right, then the stop block at the left end of the keyframe must be adjusted. It normally is screwed into the case, so just remove it, install or subtract shims, and screw back.

Shimming the stop block is normal, because the felt often compacts from the action coming back after using the una corda pedal. Make sure you check this if the piano has been stored for a time on its side, since the weight of the action against the stop block compresses the felt. If the shims need to be removed, as would be the case if the capstans are off to the right, be careful. Something has caused this and should be corrected.

There is the far chance that the action was improperly aligned in the factory, but not often. If the hammers have been replaced poorly and the hammer angle or hammer travel are way off, check here. More likely, check to see if the pinblock has been replaced. If the string alignment has been changed through altering the plate, not only will the action not line up, but the dampers will not, and the sidebearing on the bridge pins will be excessive.

As a caution, check to see if the capstans were centred in the keys, or that the keys are properly spaced and not warped on the samples being used. Is the action positioned on the keybed correctly? Since the bass strings cross the tenor at an angle, pulling the action in and out will change the hammer to string alignment a little. As a final check, did you rotate the whippen flanges when they should have been tilted, or vice versa? Remember to favour the strings which have agraffes when choosing where to align, since the upper treble strings with a V-bar can be slightly aligned to the action.  

GRAND REGULATION - part III

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 how to reshape in the home. Remember that a well-shaped hammer not only sounds better, eliminates a lot of needless voicing and wears longer, but also makes more money and a better reputation for you. Note that after traveling and angling, the hammerstriking surface must always be filled to square it to the string. 

Regraphiting the jack top and balancier window is Point 19 on the checklist. The easiest way to do this is to brush on Dag 154. Keep in mind what we are doing here. Generally speaking, the less friction there is between the moving parts of the-action, the better it works. Recently for this reason, many pianos manufactured today use teflon (often coloured blue or green) at such friction places as the top of the jack and balancier. Teflon as used here is definitely superior to graphite. The knuckle never gets coated with teflon which has rubbed off like the graphite does. A knuckle should be clean and smooth to function at its best. If dirty with graphite, clean it! For this reason, after applying the Dag 154, take an old treble hammer and rub these surfaces, or burnish as it is correctly called. This helps in making the surfaces even slicker by polishing and takes off any excess graphite which otherwise would have worn off onto the knuckle. 

Point 20 is spacing the jack in the balancier window. Remember to check and make sure the jack works freely after spacing it. Do not space Steinway teflon bushing jacks in this manner. Hammering on a teflon bushing will ruin it. Remove the centre pin and put a slight bend in it, then reinstall the centre pin. 

Next, we go on to repairing the knuckles, Point 21. Good quality knuckles have been hard to find. Manufacturers have been able to get a better quality buckskin. But only in the past couple of decades have really high quality knuckles become available.

As a technician, you have to decide whether to use the old knuckles which the piano has or to install new ones. If the knuckles are of good quality and are just a little worn and slightly out of round, then it is acceptable to restore them.

If the knuckles are of poor quality (some of late are not even buckskin but rather cowhide), or if they are very grooved or flat, replace them. For the benefit of those technicians who work on Steinways, felt bushing shanks and flanges have now become available which are of the finest quality. Slightly flattened knuckles can easily be made round again. Purchase some good quality wool yarn (not synthetic) and a large needle with an eye large enough to hold a strand of yarn. Pass the needle with a few strands of yarn into the knuckle, at the point where the knuckle rests on the balancier. The new yarn goes between the leather and the knuckle core. The fibers of the yarn will intertwine with the core and become permanent. Cut off any excess yarn from the sides of the knuckle and you are in business. As a final check, squeeze the buckskin of the knuckle and look for any slack. The leather should be nice and firm, with no visible play.

If the knuckle is a little grooved, I like to file this groove away and make the surface smooth again. In later regulation, the whippen will have to be aligned to the knuckle. If this groove exists, any alignment of the whippen will result in the jack hitting upon a new part of the knuckle. The jack height will then vary as the jack makes a new groove, and repetition problems will result, if it no longer has the tolerance it needs. 

Sometimes we find a hard knuckle. Usually this is from glue getting on the leather when the knuckle was made. The buckskin should only be glued at the very ends the working part being free against the core to flex. To eliminate a noisy knuckle, prick the leather with your voicing tool. If this does not work, replace the knuckle. When replacement is in order, be sure to glue it in proper alignment. Nowadays, knuckles are often seen which vary in their alignment. The core should be at a 90” angle to the shank, but I have seen many where the rosewood was so far bent out of shape that the knuckles were 1/16” off from the neighbouring knuckles! Combine this with cowhide being used instead of buckskin and you have a piano that not only plays unevenly, but cannot repeat since the jack hangs up on the rough fibres of the cowhide. The only remedy here is to replace the knuckles with ones which have good buckskin and to properly align them. The same goes for the felt knuckles which Steinway used for a while. Next week, we will continue with Point 22.   

GRAND REGULATION - part II

Having discussed section I, The Keys & Keyframe, last month, 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 purchase from the factory the set off our reamers. These can be used with equal success on regular felt bushings. Remember Steinway uses a rolled pin slightly rounded on each end. Oversized rolled pins can be purchased from the factory. Also available from the factory is a kit with both sizes of teflon bushings and oversized centre pins. Regardless of what can be said pro or con about their new bushings, their rolled pin remains superior, I use this pin in regular felted bushings as well as in Steinway centres.

Think for a minute about what happens when we use a regular centre pin. In the process of cutting off the excess pin, the pliers squeeze and make the pin oblong at the end.

Depending upon how sharp your pliers are, you also leave a burr, either large or small. Some technicians file down this end of the pin to correct the burr and oblong end. Great, but this still can leave the edge of the pin sharp enough to eventually cut into the felt bushing. This filing also takes time. If it only takes an extra 20 seconds, this means an extra half hour to repin and file a complete set.

Other technicians cut the pin off a little ways away from the side of the shank, so that the burr does not have contact with the bushing. This looks tacky and can result in the pins touching each other, making it hard to align the flanges. For what little more the Steinway rolled pins cost, I always use them to save time and to eliminate any chance of ruining the bushing. It also keeps the job looking neat by not having the centre pins sticking out from the bushings.

To conclude our discussion on action centres, let’s compare repinning versus using solutions or the “zapper.” If a centre is loose, we have no choice but to repin, unless we want to take the time to rebush the shank. If the centre is sluggish we can: 1) remove the pin, ream the bushing to the proper tolerance, and install a new pin; 2) apply a lubricant to make the centre “work easier” (the only two I know of as being the correct lubs for the job are an 8:1 solution of naptha / mineral oil and an 8:1 solution of naptha / silicone as sold by the Wurlitzer people); 3) apply an action shrinking solution such as water / alcohol or the solution as outlined in the Baldwin service manual; or 4) use electricity to heat the centre pin, causing it to dissipate moisture from the bushing and causing the fibers around the pin to be “ironed,” better known as “zapping the pin.”

Of these four methods, only the reaming and the “zapper” are instant in their results. Applying solutions can mean awaiting time of up to 24 hours, depending upon the solution used. None of the other three methods has been shown to be as long lasting as reaming.

If the centre to be treated is actually frozen, meaning the hammer swings two arcs or less with the pendulum test, the only permanent solution is to ream the bushing. Using the zapper on a frozen centre usually results in cooking the birds-eye hole in the flange. Using a shrinking solution on frozen centres is always time consuming and rarely permanent. Lubricating a frozen centre is a complete waste.

For sluggish centres - that is, ones which swing three to six times - it is dealer’s choice which of the four to use. Just try to pick the best method considering time, season of the year, cost to the consumer, and previous knowledge of how the methods work in your climate. If undecided, ream, for that is the most permanent.

When repairing action centres other than the hammershank / flange, remember all of the other centres are supposed to be more loose than the hammershank. Going in descending order of tightness: hammershank, whippen, balancier, under lever flange, jack, underlever top flange, and sostenuto tab. In recommending a good test for these other action centres, I would begin by saying, let well enough alone if nothing seems wrong. Obviously, if a centre pin has worked itself out and is causing a loose flange, repair it. Or, if encountering repetition problems, it looks like a certain action centre is sluggish and thereby causing slow repetition, remove the offending part and repair as needed.

As far as useful tests, a sluggish jack can easily be tested by lifting up all of the hammers and looking at the top of the jacks. A sluggish jack can be spotted by finding a jack which has not returned to its rest position, and so is out of line with the other jacks. The sluggish whippen, balancier, and damper centres are a little harder to test. Try moving the part with a finger or screwdriver and check for undue resistance. Just remember each time a centre pin is removed from the birds-eye, the hole is enlarged a little and the same size pin reinstalled will not be as tight as the original. So do not extract a centre pin unless it needs to be.

Now that we have spent this whole article on action centres, the remaining procedures of section II, The Top Action, will be discussed in the next post. If nothing else is remembered about action centres, make sure the centre pin is tight in the flange. The pin rotates freely in the bushing, not in the birds-eye.