Big Bang Theory of Regulation Verticals II

I hope all had a restful, relaxing, and regulated summer.

Just a reminder to what the Big Bang Theory is: the greatest improvement in the performance of the instrument with the least amount of time and cost. This requires an efficient ordering of work as well as efficient work habits.

Last June we left off the discussion on upright regulation with a quick note on setting key level. I would like to expand on that subject. Those instances where I do not have enough time to finish a key-leveling job, I will start in the middle octave of the piano where the problems are usually the greatest. Start by setting the let off for C4 and C5 so we can know what minimum key travel is needed for full action cycling with a sufficient amount of after touch. I use a 6” ruler, which will span the octave and will level the keys up to .005” paper (usually green). Yes, you can go further, but we only have 10 min. and the whole center of the keyboard has insufficient key travel so we concentrate on the worst first and if the key is within .005” of its proper height it is no longer the worst problem. I will repeat the procedure alternating octaves above and below the middle octave until I run out of time.

I think I have a pretty slick method for regulating let off but it is hardly original with me. It was something I picked up from Bill Spurlock many years ago. Bill will sell you his let off regulating rails or you can do as I and just use wood sticks about ½” square of various lengths from 10” - 19”. Place the sticks between the rest rail and hammer shanks, propping the hammers up to the strings. If the stick doesn’t get you all the way to the proper place, shim the hammer rail with rubber mutes the rest of the way. Set the hammer to the desired let off (1/8”) and regulate the let off by listening for the click. If you see the hammer moving you will probably have set the let off too close to the string. All you want to do is trip the jack just as it brushes by the hammer butt. This is a very fast and accurate method for let off regulation and unlike other procedures it is fast and not dirty.

My method for setting the dip may be a little unorthodox, as I have never found a description of it in any literature. It is not appropriate in every circumstance but when it is, I can set the dip very quickly and accurately. I base my method on the following logic: if lost motion is gone, the key height correct, the let off properly set, the key at full dip should be consistent all the way across the keyboard. I set a number of samples, usually 4 or 5 each of the black and white keys, remove the action, place a 4’ ruler on the keys and fill in the blanks. On most lower quality instruments you will have to be careful with the top section of keys, as they will probably not have sufficient front weight to hold the key down. Gently depress the key behind your straight edge and fill in the gap. The results will give you a very even key dip and after touch, it wont be perfect but you only had 10 min. and no one has done anything with the dip in 60 years so you will have made a significant improvement. The piano will be easier to play, playing will be more enjoyable, lessons will continue for a couple more years, the piano will be tuned a few more times, more music will be made and world will be a better place, just because you put a couple pieces of cardboard under some keys.

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