Posts tagged key

Piano Touch Weight

When you ask a child to draw a picture of a car, invariably it looks like this – wheels (with spokes hahaa), windows (again with panes lol) and exhaust.  Much is the same when we think of pianos – black and white keys as well as strings and hammers.  Everything in between magically gets glossed over.  But it’s in the attention to such details that make a piano go from just ho-hum to exceptional.  There are times that you sit at a piano and it REALLY responds.  That piano makes you not only sound good but it also makes you want to play MORE! That’s because someone somewhere in the world has connected the dots from keyboard to string.  More accurately, that’s the evolution of many hands spanning 200 years or more with the inception of keyboard instruments.  It’s naive to say that one person designed the car as we know it today… so too many people have been involved over the years with the development of the piano.

But there are four basic elements from which we derive “good” touch at the piano.  They all must be in check for a piano to function.  And they are:

Down weight

Up weight

Friction

Action ratio

The down weight refers to the pressure required to press down a key on a piano. The up weight is the weight needed to bring the piano key back to resting position. Friction is the perceived weight on all the joint and moving parts while the action ratio is the lever system (called whippen assembly) that multiplies the speed, weight and force of the hammer from the key.
So… in my curious nature, i start asking questions. Why do we need friction? It’s not that we NEED friction but too little of it, and parts are usually too loose and will start producing noise. Too much of it (as on the Chickering grand i just worked on) and the touch feels too heavy. Concert instruments should range between 50 and 55 grams of touch with friction representing 10-15 grams of that touch weight. With too much friction, the piano i just worked on clocked in at just over 80 grams of touch – completely unreasonable for normal playing. Question 2 – well… why not just counterbalance the touch using weights in the keys? If you’ll notice on the sides of your piano keys there are small circular weights made out of lead. Well the lead weights will have some effect for the initial movement of the hammer but in dynamic playing those lead weights will not compensate for rotational inertia at all. Nor will they do any good for either friction or up weight. So why not then just have really light parts and light friction? Good idea but… the speed of the key is also determined by the return… the return requires weight.
The balance then is this – 2 elements of the four are relatively easy to control while 2 are not. The action ratio – the intrinsic design of the piano – not so easy. That’s like saying “Can we just change the pistons on this engine?” Not easily. The second part is the up weight. The up weight carries direct correlation to the hammer weight alone. The other two factors – friction and down weight can be readily altered. Friction is by far the biggest culprit that i’ve seen. And down weight can be counterbalanced with the aforementioned weights. Once the balance is achieved however, the piano becomes a wonderful and inspiring instrument. Below are two pics of lead weighting this last week – some tools of the trade and different lead weights across the keyboard ready to be installed.

Cause & Effect: Piano Key Sticking

This post speaks to the problem of sticking piano keys.  There are usually about 6 spots to check on any piano if a note is not returning to normal playing position.  But before we get into the mechanical, think of the obvious… is it getting blocked? I mean… believe me when i say i’ve seen LOTS of things inside pianos.  Here’s my list thus far: pencils & pens, toys, hair pins and bands, sheet music, tools, rubber bands, paper clips, coins of various sizes, ladies press on nails (ewww… that kinda creeped me out finding that one… especially since i got the piano from a home where she had died), believe it or not metronomes and decorative piano blankets.  Hmmm have i missed anything? So make sure it’s not getting blocked.

Once you’ve determined that it’s not blocked or broken, however, there’s a REAAAALLY good chance friction is to blame.  Usually the hammer FLANGE is the culprit – it’s the joint connected to the hammer.  About 80% of the time there’s wayyy too much friction on that joint and the centre pins need replacing.  Two other joints – the action flange (flange is just another word for joint BTW) and the whippen (repetition lever) also have jointed parts.  Any time you introduce a joint, you also have potential for problems.  So that makes up 3 of the problem areas.  Then the key stick has two bushings – each of which could also have too much friction.  And finally, the key slip – the rail in front of the key sometimes catches on the front of the key.  Invariably it’s one of the 6 parts.  How do you go about fixing it? Hahaaaa… i didn’t mention i would give the solution… only the cause of the problem.  MOST problems can’t be fixed without a technician.  Sure you can look down inside and see if there’s something obvious but if it’s not… you need to get an expert in to address the problem.

Spinach Dip… Artichoke Dip… Piano Key Dip?

Dip refers to the distance the key travels downward.  So from the very top of the keystroke to the felt cushion at the bottom, the dip is the distance between the two.  Why talk about dip?  All pianos should have the same distance right? You would think that this is standardized but it’s not.  And believe it or not, 1 millimetre makes a HUGE difference in dip.  OK so there are some basic guidelines that piano makers follow.  Historically 3/8 of an inch was the standard.  This is just shy of 10 millimetres ~ 9.55 to be exact.  Personally i tend to lean towards just a hair past 10.  Bosendorfer publishes 10.2.  Yamaha and Kawai are in the vicinity of about 10.0 to 10.5.  I find that ‘shallow’ pianos – ones with under 9.5mm and ‘deep’ pianos – more than 11mm are ones that stand out.  And what happens if this is adjusted too deep or shallow?  Well, too deep and the keystroke feels a bit like an army tank.  Quite often i’ve heard it said that the piano feels ‘clunky’ or heavy.  This stands to reason because of the amount of travel your fingers are doing.  It requires a lot of effort to play a deep keyboard.  Too shallow and you may experience lack of power or a feeling that you’re hitting a wall.  Because the benchmark is closer to 10 these days, a 9.5 or shorter dip results in feeling somehow confined. 

So better than spinach or artichoke dip, a good key dip results in tasty playing.

The Black Hole of Pianos

Every piano has one… a black hole.  It’s the place where all the pencils disappear to.  Paperclips magically are sucked into it… Heaven forbid anyone should be doing their theory homework at the piano and an eraser falls inside.  And once inside the abyss… gone forever!  HAhaa… at least that’s what i used to think when articles would fall inside the piano when i was a kid.  And on pain of death we were threatened to never go tinkering around the inside of the piano (which is still probably good advice for kids and pianos…lol).  So when the piano tuner would come, he would unravel the mysteries of the universe… “Well… looks like that click sound is actually coming from a pen that fell inside.  Oh and here’s another pencil.”  I remember seeing the inside mechanism of a piano for the first time in my early teens.  (Formally called the “action”).  When i witnessed the hammers and levers i remember having this brainwave. “Sir? Can you make the keyboard on my piano heavier?”  We had an old upright piano and with 4 kids – 3 of which ended up with diplomas in piano, you can imagine the beating it endured.  But when i went to my teacher’s place where there was this beautiful modern 7′ Yamaha grand piano, i noticed how vastly different the touch was.  And so the answer from the tuner? Simply “No”.  No explanation. End of Story.  I thought to myself, in all this gobbledeegook of levers maybe there was some adjustment that could be made to give me a grand touch.  I was young and naive and this technician had no time to explain and so i was left with no alternative than to think that it’s impossible.

For the most part, however….unfortunately he was right.  I’ve had MANY people ask me to transform their piano into a firmer touch but to understand piano touch more, i’d like you to think of your piano like a scale.  On one side is the key of the piano – the black and white notes.  On the other side remain the hammers and the action.  So most pianos have about 55-60 grams of touch on each key.  What that means is:

                         Finger Pressure (55grams) = Hammers + Friction

Most of the weight of a piano is in the physical motion of the hammer itself.  Now if you know anything about hammers, put one on a scale and you’ll find out that it weighs about 8 grams.  Attach it to a piano action and all of a sudden, there is a 5:1 ratio of hammer weight.  What that means is that the lever system in the piano multiplies the hammer weight by 5.  An 8 gram hammer then will feel like 40 grams at the keyboard.  Add 15ish grams of friction and VOILA! Piano touch.  A 9 gram hammer (times 5=45) plus 15 grams of friction forms a touch of 60 grams at the keyboard.  ONE gram on the hammer makes a 5 gram difference at the keyboard.  When you think that a nickel weighs 5 grams, adding one-fifth of that is not a whole lot of weight and yet you’ll EASILY feel the difference installed into a piano due to the ratio.  Make sense?  Is it not possible then to simply add friction to the piano? Adding friction is not the answer.  Friction is a careful balance.  Too little and the piano feels too ‘loose’ and results in noise. Too much friction and the piano has sticking parts and feels sluggish.  If your piano is old however, you may have worn out “joints” or pivot points.  There are 2 areas which can be monitored which make any piano feel more “positive”.  One is key bushings (see the article entitled “Aye There’s the Rub) and the other is called the hammer flange.  (A flange is just a fancy word for hinged part on a piano).  The hammer flange… if you follow your eye down the stick (called the shank), you will see that it is jointed at the base.  New flanges (albeit costly) and key bushings are the biggest culprits for too much/too little friction.  And so without opening pandora’s box more… my original question to the tuner:  Can’t you change simply change the touch on the piano?  Operative word in that sentence is “simply”.  It can be done.  It’s just not simple.

Aye, There’s the Rub

Indeed, friction is one of the piano technician’s worst nightmares.  At best, the piano is a simple machine – you depress a key, it lifts a hammer to strike a string.  At worst, it’s a complex mechanism where levers and joints are in contact all the time and each surface area is potential for friction to either be too loose or too great: too loose and the piano feels ‘warbly’ and too tight and it either doesn’t function properly or feels like you have to work too hard to compensate for the touch. 

I learned this only a few years back but the formula for touch on a piano is relatively simple (operative word being ‘relatively’).  There is a 5:1 ratio of hammer weight to key.  What that means is, for every gram of weight at the hammer there is 5 grams at the keyboard.  An average hammer weighs in at about 8 grams (multiply by 5 = 40 grams).  So if average touch on a piano is 55 grams per key, where are the other 15 grams of resistance coming from?? Answer: friction.

One side of key bushings replaced

Today i had the opportunity to redo key bushings on a fabulous grand piano owned by one of the best jazz musicians in the area.  With a lot of playing (both from his own practice and from his students), the bushings around the contact points on the keys were completely worn making almost a ‘knocking’ feel from side to side.  A bushing is nothing more than a substance used to reduce friction between two contact points.  In pianos, bushings are almost exclusively made out of cloth (some people mistakenly call it felt but truly it is cloth – woven together).  The cloth then allows the interaction of joints.  Centre pins are made out of steel and they need to interact with wood.  Without bushings these two hard substances would click and knock together.  As well, friction can be taken up by cloth in varying degrees of thickness.  So the cloth is the perfect substance for acting as the ‘spacer’ inbetween. 

Next time you’re at a piano, test the bushings.  Take one key and swivel it from side to side and see if you sense a knock or a thunk.  This will tell you they need replacement.  Simply steam out the old ones (see pictures) and glue in new ones and you’re good for years to come.

When Green does NOT mean Go!

Grand ActionRecently i had the privilege of working on a brand new piano which will remain nameless.  The instrument was adequate but one problem kept cropping up – and that is that the necessary friction was all over the map.  When you play a piano, in the 6000 moving parts, friction accounts for about 15 grams of touch on the instrument on average.  You might think that absence of all friction would be ideal but that is not true.  Some resistance is required.  So what happens if the friction is excessive or absent?  You get a poor playing piano with a VERY inconsistent touch.  On this particular piano, the joint at what is called the flange was completely out of line.  In addition, key bushings were WAY too sloppy.  How does that happen when a piano is brand new?  Simple.  Use green lumber during the manufacturing process.  Wood that has not been dried properly is known as “green”.  If the wood contains too much humidity and has not been thoroughly dried naturally or in a kiln, the wood eventually will dry out and also warp.  In this case, the once fitting joints obviously were not made with properly cured wood.  It is difficult from the consumer’s point of view to determine this.  Reputable companies cure their wood for up to 2 years before manufacturing.  Companies of ill repute simply mill the wood and insert into the piano.  What ensues is a whole raft of issues to deal with later.  My advice? Be REALLY discerning on a new piano with regards to touch.  If it feels ‘sloppy’ or wiggly or tight, there’s a good chance it has substandard parts – ones that are not correctly fitting.  And word to the wise: if the wood isn’t right, there’s a good chance the felt is poor, the design is poor and other materials are also cheaply made.  Buyer beware: you DO get what you pay for.

PS… the picture is one of a grand action.  The red circles are joints – a steel pin surrounded by cloth inserted into wood.

Hey That’s No Sweat…

Ivory keytops

Ivory keytops

Ok maybe i’m a product of the 60’s… but the saying “no sweat” was a common one.  Well in pianos, hand moisture IS a problem! When you’re feeling nervous and performing in front of others the last thing you need is to slip and slide around on the keytops.  Enter ivory.  Ivory is a very interesting substance in that it actually is porous.  It absorbs hand moisture.  I asked someone the other day if they had ivory keys – the answer “i dunno… how can you tell?” Well, that’s the simple part – 2 ways – one is that every piano i’ve seen made out of ivory has a very faint seam line where the whites meet the blacks and second, you’ll usually be able to see the grain of the ivory, much like you would with wood.

Due to the necessary ivory ban in 1970, piano makers have made their keytops out of plastic.  Only problem is… there’s no accounting for the hand moisture.  Innovative companies have actually made realistic simulations – called ivorine.  As well, Kawai builds an antiseptic into the makeup of their keys.  Both of these substances look and feel more like the real McCoy.  Unfortunately, they only make these keytops on their very high end models.  Subsequently, plastic has become the benchmark for pianos.  Now don’t get me wrong, i don’t condone the killing of innocent elephants for their ivory but i must say that ivory is a very interesting substance and part of piano manufacturing history.  If you ever get a chance to, feel the keys on some old upright piano.  It’s unmistakable.

Drive the Car

f1I was 22 years of age when i was hired by the local Baldwin piano store.  The owner was a technician and the first words out of his mouth were “Glen, you may be educated in performance but i just want to tell you that because you know how to DRIVE the car, don’t presume that you know how the car works”.  He then proceeded to tell me that the mechanic is not the driver in the Formula1.  And so i took his advice to heart.  I began to learn about the insides of the piano.  I will say however, that being a driver and a mechanic both have distinct advantages.  I remember this boss calling me to his workshop to try out a newly rebuilt piano. He’s all smiles and with big outstretched arms he points to the piano… “VOILA!”  He asks me to play.  I remember not being impressed by the piano and how put off he was because i couldn’t properly articulate what it was i didn’t like about the piano.  And then it occurred to me that regardless of what your thoughts are re: the makeup of the instrument, it’s the driver still that counts – they’re the ones who are going to play this instrument.

grandSo how do you properly test drive an instrument?  It’s funny because i get lots of students through my doors looking for pianos and who do they get to preview the piano? Why, the teacher no less.  But again, teachers are drivers and usually have very little understanding of what is going on in the piano.  They walk around the instrument and give the ol’ inspection “mmm hmmm’s”  but don’t really know what to say.  LOL…ok this is funny – so you know the grand lid on a piano? It’s the 45 degree angled part held up by what is called a prop stick.  After previewing a Steinway grand for her client… she finally said.  “SOooooo, this is one of those ‘one-stick’ pianos”.  (most pianos have 2 or 3) OK ok ok… i thot it was funny… kinda like judging the car by the antennae.  Anyway… here are some tricks and tips on testing pianos:

  1. Test the piano at different volume levels.  My trumpet teacher used to say “any 2 year old can blat a horn – it takes a master to play it quietly”.  Much is the same at the piano.  If a piano is ever going to misfire, it will be at soft volumes
  2. Play each key – find out if there are any sticking or problem notes – listen especially for buzzes and rattles
  3. Find the crossover.  The crossover is the spot where the bass copper coloured strings change to steel strings.  This is usually a problematic place on most pianos for consistency.  Great pianos will have a very gradual change in tone.
  4. Sustain.  Sustain is your friend.  Take one note – moderate volume – play it and listen to how long it takes to die away.  If it’s short lived, quite often the soundboard (the amplifier) is dead.
  5. Excessively loose or heavy action.  Take one key – depress the notes on either side then grab hold of the sides of the key and wiggle it back and forth – left to right.  Does it ‘knock’?  Worn out pianos usually will have a notable ‘click’ here.  As well, lift the very front of the key by the overhang – ever so slightly (you don’t want to rip off the keytop!)  It should rise only about 1/16″ but it should also fall on it’s own weight.  Newer pianos quite often are tight and if there’s too much friction here, they won’t fall back to rest position.
  6. Finally, test the workings of the pedals.  Make sure the damper blocks lift simultaneously and in a comfortable manner.

Oh there are many many other tests you can do… but these will cover the basics. Enjoy!

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