Jim writes: << I don't think I can add much to what has already been said, except for one thing. I don't remember who said it, or when, but it had to do with pinning the jack as tightly as the balancier. I don't agree with that. You are far more likely to have repetition problems due to a jack that's too tight than you are with one that's too lose. >> Greetings, Um, That was me that said that! I have found that an action will play just as fast with a jack pinned at 6 grams as a jack pinned at zero friction. The jack pinning doesn't seem to interfere with repetition until it passes 8 grams, and even so, you have to have somebody that can play real fast to create a problem. A 6 grams, a jack will still move faster than the eye can see. For heavy use pianos, the pinning will loosen up from where it begins, so I have always pinned them near 6 grams and never had a problem with repetition speed. The jack will move faster than it needs to, even with 6 grams of tension. (Alicia de La Roccha played Ravel on a piano I had set up with jacks pinned like this, and told the stage manager it was the first time she had ever found a piano that needed nothing but tuning.) Many techs think that looser pinning and/or stronger springs will increase repetition speed, but I disagree. Repetition speed depends primarily on how fast the key returns and checking height. The jack reset speed of an a spring set to throw the hammer off the balancier will not exceed that of one that has a so slow of a hammer rise that it cannot be felt in the key. If you compare return speeds of two adjacent keys, one with a lot of spring, the other with much less, you will see that both come up together. The problems with heavy springs are found in pianissimo playing, where the resistance to escapement is higher due to the drop button interfering at the last possible moment of control. The near instant empirical capacity of this list is such that if we wanted, there could be a hundred different techs try the tighter jack pinning and publicize their findings in the next couple of days. I certainly don't think everybody should believe what any one of us says! Try a tighter jack for yourself and see if you can play it fast enough to fail, let us know what you find. Regards, Ed Foote RPT http://www.uk-piano.org/edfoote/index.html www.uk-piano.org/edfoote/well_tempered_piano.html
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