Touch regulation...

After my struggles with key height chronicled in the last post I decided to go back to Danny Boone's book Regulating Grand Piano Touch and Tone. And read it again. Duh, right there it was! Key height is governed primarily by the balance rail pin and to some lesser degree by the backcheck rail felt. That information was buried in one sentence on page 84. My guess as to what I'd done wrong was correct. But it was a hard way to learn that lesson.

The first three hours of Memorial Day was spent undoing what I'd done incorrectly; then setting the proper height with all the keys seated on the bed level with each other. It's amazing what a difference a paper punching only 3/1000 or 5/1000th of an inch thick can make. Gradually I got the feel for the correct sizes and how many to use. The book says with practice "you should become able to level the white keys in one or two passes". For me, it was more like four or five. And, of course, there are the sharps as well.

Since I didn't know what to order in the first place I got the "assortment package" of punchings both for balance rail pins and front rail pins. The good news is I had everything I needed. The bad news is I now have a lifetime supply -- they come in packages of 1000 and they sent about a dozen different sizes of each.

After setting the key heights, I squared, leveled and spaced Zelda's keys -- no gap teeth, please. Then it was time to set the hammer line.

This is where it gets pretty precise -- the hammers need to have a "blow distance" of 1 3/4 inch below the strings. So I took a level with a t-square built in and checked the height of Zelda's strings from the key bed. She really was built well. A hundred years later and the deviation is at most 1/64th of an inch on a few of the strings. I'd call that level.

So I rigged up a taut line at exactly the 1 3/4 distance below the string (see photo) height; then moved the action to the workbench. Another four hours of my Memorial Day holiday was happily spent adjusting the hammer line to the correct blow distance. The photo shows the hammers before adjustment -- some were less than a half inch away from the strings; others were over two and a half inches. The point of all this is to create an even touch and response. For those that are too close you couldn't get a forte if your life depended on it. For those too far, you could defintely get some power; but the sound would always be late --notes played at the same time would sound at different times.

But it isn't over yet! Touch isn't just about key height and hammer blow distance. It's also about making sure the distance that each key travels to exert a blow to the string is the same as the key next to it. Otherwise the pianist has no control. So the next four hours of my Memorial Day holiday was spent happily adjusting what's called "key dip".

While the punchings on the balance rail have more overall impact for their size, the range of motion for each key is incredibly varied. As precisely made as the keys are -- they are, after all, over a hundred years old. Time gives not only character but lots of variation. The number of punchings required to correct these variations multiply almost exponentially. Hmmm, maybe I don't have a lifetime supply after all -- at least not for front rail pins.

I completed all the natural keys. Stared at the clock -- 10:30 PM and realized that there wasn't an ounce of energy left to do anything else. And that's where I am now.

Last night I took a little time off to do some minor retuning -- all this moving in and out of action parts, etc. has had rattled the old girl a bit. Tonight I'm writing. And tomorrow, I turn my attention back to the key dip of the sharps. It'll be a bit more complex -- one, because the punchings are harder to get at; and two, because there are seven or eight "recommended" ways how to get the correct measurement. One book just says "go by feel" -- how do you feel 3/1000 of an inch and know if it's correct or not?

I bought a handy dandy Davis sharp leveler adjustment from Schaff. I'm going to carefully reread the instructions tomorrow morning (my last Thursday off before we start summer hours at the shop) and devote probably the next four hours to leveling out Zelda's sharps.

After that, I'm not sure. I'm thinking about beginning to play with some preliminary wood refinishing approaches in some test patches to see what looks best.

Or, if it's not 94 like it was today, I may actually take a bike ride around the island. Bending over a bench -- even happily -- for 10-12 hours making painstakingly precise adjustments is a little tough on the back.