pianotech-digest V1997 #710

[Delwin D Fandrich]

james turner wrote:

> Can someone suggest what type of key dip block is best to use on the
> white keys?  I have had trouble with the wooden one warping.

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I now have several of them. All of them wood. And all of them slightly different. They are
made for different amounts of key dip and for keys of different lengths. (The slope of the
top will be shallower for long keys than it is for short keys.)

I make them out of scrap solid maple or scrap left over from pinblock planks. If the wood
has been around your shop for awhile it should be fairly stable. Stable enough for this
task anyway. Determine the proper key travel for the particular action you're working on
and cut a piece of wood approximately 22 mm wide and 50+ mm long. To start with it should
be a uniform 11 or 12 mm thick. Place this on the key and depress it until the key
bottoms. Use the same amount of pressure that you use when you are actually setting key
dip. Scribe a line along the side using an adjacent key as a guide. Sand or plane the
piece down until the top is exactly flush with the adjacent keys when the key you are
testing is fully depressed. If you want to be really fancy you can glue some very thin
bushing cloth or some very thin leather to the bottom to help prevent scratching the
glossy plastic keytops. And there, you have it.

Even though key dip "standards" are rather casually tossed about, there really are no
standards. There is actually a range of standards. Rather than forcing the action to
conform to the key dip block that you already have it's better to make the dip block
conform to the action at hand. With some practice this whole operation will just take a
few minutes and you can easily custom make a dip block to fit any keyset or odd set of
action parameters that you may encounter.

There are a couple of things to remember when setting key dip. The keys have to be as
perfectly level and square as you can get them before you start. You need to practice
always putting exactly the same amount of pressure on the dip block each time you use it.