Blog Top

Friday, 24 October 2014

Regulation of a Grand Piano Part 1.

Regulating a grand piano is not as simple as just taking accurate measurements and making slight adjustments. Many years ago I telephoned an Action Manufacturer to order some action parts and during the conversation I asked if there was a 'regulating manual' for their actions. I thought there must be some written instructions but the response was an emphatic: "No!" 

So we in the piano trade are left to make as much sense of regulating a piano as we can using what experience we have. There are good books which will explain what happen during the stroke of the key but not even these will help when correcting some of the many possible problems. Regulating work, even on new pianos, is not as reliable as we might expect. 

Fortunately, there are principles which, when understood, form a structured approach to get the job done. The following is my own method for regulating - it is not the only way, but I have found it to work well on most pianos.

Please note: while regulating pianos, some improvisation is required to get the best out of any given piano.

Most actions work well if the depth of touch is 10.5 mm. and the hammer blow 47mm. 

1. First job is to level the keys and set the depth of touch - best done with the upper part of the action separated from the keyboard. With a set of lead key weights, place the weights on the front end of the white keys (front of the ivory key tops so the the keys are resting on the front-touch baises) and level the keys so that across the keyboard they appear perfectly in line. Any adjustments are made using paper or card washers under the front-touch-baise.

Then, for a few sample keys, attach the weights to the back check and measure the depth of touch at the front of the key (as compared to the keys with the weights still sitting on the front - I set sample keys every 5 or so white keys). Touch depth should be 10.5 mm.

This done, gradually transfer the weights to the back checks and level each of the white keys to be in line with the sample keys. This takes care of the white keys.

For the sharps: with the lead weights still clipped to the back checks, ensure that the top surface of the sharps, when resting on their individual front-touch biases are about 1 mm above the top surface of the white keys. Again, set a few sample sharp-keys ensure sharps are level and then proceed across the keyboard. 

Then, with a few sample sharps, attach weights to their back checks and set the height of the front end of the sharps to be 12 mm above the top surface of the white keys (These white keys must also still have the weights on the back end of the key). Using sample keys as a guide, continue to level all the sharp keys across the keyboard.

The upper part of the action is now screwed back onto the keyframe.

©
Pianology


No comments:

Post a Comment