---------------------- multipart/alternative attachment The balance weight is the modern standard and is calculated by adding the downweight to the upweight and dividing by 2. Thus DW = 52, UW = 28, BW = (52+28)/2 = 40 (and friction = (52 - 28)/2 = 12). Note that as the friction increases or decreases, the balance weight remains the same. If you add one gram of friction, the DW becomes 53, the UW becomes 27, the balance weight remains the same. As you ascend the keyboard, the friction tends to decrease as the hammers get lighter and there is less weight bearing on the friction points. Thus, even if the balance weight is uniform from top to bottom, the DW will decrease as you ascend the scale and the UW will increase. The standard I use for concert instruments is 38 - 40 grams balance weight. It sounds as if you are right in the ballpark, but the only way to be sure is to measure the DW and UW for each note and figure it out. Minor changes can be made to the balance weight by adding to or subtracting from the front weight of the key in an inverse ratio of 1:1. One gram added to the front weight will decrease the balance weight by one gram and vice versa. In order to make those changes, you will need a scale and platform with which to measure the front weight of the key. David Love davidlovepianos@earthlink.net ----- Original Message ----- From: To: caut@ptg.org Sent: 12/15/2003 3:26:32 PM Subject: Touch weight I've just done complete down and up weight measurement on the new D. From C1 - F2, the down weight is between 52 and 55 grams. The rest is between 47 and 50, with a few 45's and 46's in the 7th octave. Upweight is generally between 27 and 30 grams, with some as low as 25 and a couple as high as 34. The Piano Action Handbook says down should be 51-52 in the bass graduating to 47 in the treble, with up weights at 20. After Christmas I'm going to lube all centers and check for pinning. Hopefully I'll get better upweight measurements. Is this about what you guys are going for? BTW, is TW the difference between down and up, or am I missing something in the calculation? Wim ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/caut.php/attachments/65/a6/c4/bf/attachment.htm ---------------------- multipart/alternative attachment--
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