Posts tagged hammer 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:
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.