Providing Complete Piano Service: Regulating (Part 3)

Every piano has three basic parts, or systems; 1) the Case, Frame and Soundboard, 2) the Plate and Strings, 3) and the Action, or Playing Mechanism.     In a vertical piano the case includes the backframe assembly with the pinblock, soundboard and bridges attached, the keybed, plus the sides, front and top pieces. These last three are the finished “case” pieces we see, and are attached to the backframe with screws and glue.

In a grand piano the case includes the skeleton (roughly equivalent to the backframe in a vertical piano) and the soundboard and bridges, the pinblock, the keybed, and the rim, music desk, lid and lyre. In a grand piano the rim is an integral part of the skeleton, even though it is also part of the case in that it is finished to look nice like the other case parts. The keybed is added to the backframe assembly in a vertical piano, but is built into the skeleton and rim in a grand piano. The pinblock might be built into the piano, as an integral/structural part of the skeleton in some pianos (as it is in Steinway and a few others), and or it might be screwed on to the skeleton, or attached directly to the underside of the plate, as in most pianos. The plate is screwed directly to the backframe assembly in vertical pianos. The tuning pins are installed into the pinblock through holes in the plate, and the strings go down over the bridge, around the bridge pins, and to the hitch pins near the lower edge of the plate.  The plate screws directly to the top of the skeleton in grand pianos. The tuning pins also go through holes in the plate into the pinblock, and the strings stretch out over the soundboard, over the bridge, around the bridge pins, and to the hitch pins are the tail end of the piano and plate.

Backframe parts on verticals can become damaged, perhaps during moving, and come apart. Caster replacement on large, old uprights is a common issue. Case parts can become loose, often because of excessive dryness, and fall off. Keybeds can become loose, or change position, often for the same reasons.  Skeleton and rim issues are less likely on grand pianos (except those that are very cheaply made), except for moving damage. Lyre and pedal problems are more likely on grand pianos than on vertical pianos.   Both pianos have actions, or playing mechanisms; similar in some ways, different in others. And both types of pianos require regular service to the actions.

Grand pianos have about 14,000 total parts, including as many as nine different types of wood, and the action contains many different types of leathers and felt parts, and includes some 9,000 parts in all.   There are about 20 different things that can be adjusted on each key to make it play better (or less well), faster (or slower), more power (or less power), and more even with the keys next to it (or less even). Of course we want the piano to play fast, and have as much power as possible, and be as even and consistent as possible. Making these adjustments is called “regulating the action”, or “regulating the piano”.

Many pianos are fairly well regulated when they arrive at the dealership, but others are not. It is not uncommon for a brand new piano to need a full day of service before being sold and/or delivered to its first owner – though most do not get it. Some require even more.   But whether a piano is well regulated when new, or not – by the time most pianos are 8-10 years old their playing mechanisms are playing pretty badly – at least compared to how well they could play. In most cases all the parts are fine, and after minor cleaning (usually just removing the action from the piano, blowing it out, and cleaning the action cavity, soundboard and strings) the parts can be regulated to play pretty well during a one-day service by a competent piano technician.

The older a piano gets – meaning the longer it goes before it has any regulating done – the more time it will take to return it to good playing condition. I have found in my practice that a piano that is 15-20 years old will generally require a couple to three days or regulating work to restore it to good playing condition, and a piano in the 30-60 year range can take four to six days work.   Why does this happen?

Well, to put it simply, remember those many different types of wood (at least nine) used in the piano’s construction? Each of them swells, and shrinks, with changes in the humidity – but at a different rate. The keybed that was at a certain place when the piano was new is probably still at the same place, but since it might be thicker, or thinner, or thicker in some places and thinner in others because of humidity changes – the keyframe, and key height, and hammer height, and all the other parts, are no longer at their same relation to the strings as they were when the piano was new. Likewise, the keys many have swollen or shunken in thickness due to humidity changes, as did the keyframe, and the rest of the wood action parts.  And remember all those felt and leather parts? They are felt (softer than wood) and leather (softer than wood, but harder than felt) – and they have all (as in all) crushed and settled in. The parts they were once holding up, holding at a certain relationship to other parts – has changed.   As I said above there are about 20 things per key that can be adjusted to make a piano play better.

Here are some examples:

  • Setting/regulating the height of the keys so it is (called “setting key height”) back at its specification above the keybed, which will make it properly fit into the piano’s case parts.
  • Setting/regulating the height of the hammers at rest (called “regulating blow distance”).
  • Setting/regulating the distance the key moves down (called “regulating key dip”) when the key is played.
  • Setting/regulating the point the mechanism disengages from throwing the hammer up (called “regulating let off”) during playing.
  • Setting/regulating another part (called “drop screw”) to regulate the top travel of the wippen during playing.
  • And several parts within the wippen itself, including regulating the jack’s forward/backward position to the knuckle, regulating the height of the repetition lever to the jack, and regulating the tension spring inside wippen.
  • Setting/regulating the back checks, to adjust the place where the hammers will “check” during playing.

And before this can even be started, critical dimensions must be measured, manufacturers’ regulating specifications consulted, if available, and sample parts in each section of the piano regulated, to determine what works best for that individual piano. There might be a key dip specification given, for example, but on pianos made before about 1970 it is most always wrong (too small). Setting up samples might show the piano requires something else, and how much more, or less (and it can be as little as 0.005” to as much as 0.050” – 10 times more, or less). Most modern pianos are made on an assembly line, but it has not always been that way in the past. Pianos made before the 1950’s are much more likely to have had more individual hand work involved in its building, and therefore less consistency from one piano to the next. And even the most well-made machines can, and do, go out of specification when making things, and the dimensions specified for a particular piano may end up not even being close to what is required to make it play its best.  Parts are regulated down to a couple thousandths of an inch, which is required to achieve a smooth and accurate touch, and high level performance when played.

Many clients I see in my work say things like “I wish I could play better, but I have practiced and practiced and I just can’t get any better”. Usually they want to be able to play faster repetitions on fast music, or with more finesse on slower, softer music. I have the opportunity to show them that while their nice grand piano was designed to play really fast – it is so far out of regulation that Roger Williams could not play fast pieces on it!   I often say something like “Most people understand cars, so I will use car terms. Quality vertical pianos, with actions and keys in good condition and properly regulated can play in the 100-110 mile an hour range. And since the speed limit is somewhere between 55-75 miles an hour in the US, a piano that goes 100 is pretty good. But a grand piano action in good condition, and in proper regulation, can play 150-160 miles an hour! And the faster the piano can play – the faster the person playing it can play, and the more control the pianist can have over the action, to play loud and soft, fast and slow, and with finesse. You want your piano to play fast, like a Corvette or a Porsche, but it is so far out of regulation that it plays like a Mac truck instead.”

Then we have a discussion, talking about the things I have said here, and they begin to understand that it the reason they cannot improve in their playing is because they are playing on an instrument that cannot go any faster than it is, because it is so far out of regulation.   Back to cars: People change their oil every 3,000 miles. People change the tires every couple years, and get new brakes every 50,000 miles. The belts and hoses are replaced every four to six years, so the belts do not all of a sudden break, or the radiator hoses develop leaks, and leave you sitting by the side of the road calling for a tow. Yet the same people who take care of their car will play a piano for 10, 20, 30 years, and never have any work done other than tuning. People buy 50 or 100 year old pianos without having them inspected first, something they would never do when buying a used car of any age.   And if they were driving and stepped on the gas to jet into another lane, get onto the freeway quickly, or get out of an oncoming car’s way, and it did not perform well – they would not say “oh, I guess I am not a good driver”, but would say “I think I need a tune-up”. Yet when the same thing happens with their piano they say “oh, I guess I will never learn to play well”.

Regulating work is time consuming and requires training, practice, skill and patience. And this is the reason that only 10-20% of all piano technicians do much regulating at all.  It also requires quality (which can also mean expensive) tools. Often times technicians who do much regulating have invested in much more sophisticated tools, costing thousands of dollars, to aid in doing high level, accurate regulating work faster and with more consistent results.   And whether your current technician does much regulating, or chooses not to, has nothing to do with intelligence, or lack of it, but more with preference. Some technicians prefer to tune pianos, and provide minor services for their clients including repairing broken action parts, servicing the pedals (especially for squeaks), and replacing broken strings as needed – but may refer their regulating and rebuilding work to technicians who prefer to perform these kinds of services on a more regular basis.

Note: This is first part of a six-part series on Providing Complete Piano Service, written by Randy Potter, RPT. The other segments are: Tuning (Part 1), Repairing (Part 2), Voicing (Part 4), Humidity Control (Part 5), and Rebuilding (Part 6). It is being added to our web page in December 2014. Look for additional segments monthly until all six segments are posted here.

Randy Potter is a Registered Piano Technician (RPT) Member of the Piano Technicians Guild, and is also a member of other professional organizations in Europe and Asia as well. He was trained in tuning, repairing and regulating both modern and antique pianos, and has been tuning and servicing pianos on his own since 1976. He has attended factory training programs with many of the world’s major piano manufacturers, including Baldwin, Kimball, Steinway, Yamaha, Mason & Hamlin, Steingraeber and Kawai, to name a few. He is a regular instructor at piano technicians conventions and seminars around the world. He is the founder and director of instruction of the Randy Potter School of Piano Technology, the largest school in the world training piano technicians, which has students and graduates in over 80 countries.