What kind of piano is this? If you have to lower the drop screw it may indicate that the bore distance on the hammers is too long. Lowering the let-off button is usually accompanied by the lowering of the drop screw and vice versa. The shank relationship to the knuckle can be altered by changing the spread, shimming out the whippen flanges or the flange rail. You will have to determine the appropriate spread by trial and error probably. The harder feel at let-off of the new wippen may be because the surface area of the top of the jack is greater on the new one than the old one. What condition are the knuckles in? You may want to consider changing the knuckles if you are not changing the shanks. I would measure and calculate just how much you need to lower the plate to get the bearing you want and on which side you have the problem. Also, measure the crown. If you are lowering the plate onto a board which is already flat or worse... Lowering the plate at the outside perimeter is not likely to change the hammer bore dimension. Lowering the plate at the block might, it depends on how much you are lowering it. Are you installing a new pinblock? David Love davidlovepianos@comcast.net -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Bob Hull Sent: Saturday, March 19, 2005 7:23 AM To: pianotech@ptg.org Subject: low drop screw symptom Hello List, On a rebuild for a small but good quality grand I am replacing all of the action parts and having some doubts about the action configuration. As I regulate samples the drop screw has to be lowered almost as far as it will go. Another relationship that appears to be off is the jack to hammershank relationship which is not perpendicular but rather it is more toward the B- side (Bob Hoff terminology). How can I change this? The new (Renner) wippen with the closest match to the old wippen is the one with the added heel. The old jack tender/toe seemed to interface better with the tilted let off rail than the new wippen does. The new one gives a harder feeling ledge before let off. I don't like the way that feels. I realize that more information may be necessary and I can supply it if asked. One other thing I will add is that I had to lower the plate/string plane as much as I dared to get some downbearing. I am adjusting the hammer bore because of this. So to restate my question: What is indicated about an action geometry when drop screws must be lowered so far in order to attain suitable drop? I would appreciate your comments. Bob Hull __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
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