David Stanwood mis-understood. The MX-100 is an upright, not a grand. As he would be quick to point out the analysis and corrective methods will be slightly different. Hammer weight is not especially relevant but action geometry is and generality it is easier to correct than on a grand. His friction and balance weight figures are correct. I arrived at the same conclusions but I just did the math in my head (real itchy using pencils there) to the conclusions I wrote earlier without the exact figures. As David said, this is a geometry problem but very likely not one from the factory. This piano may well have been damaged by a drop or a fall. Examine it carefully before doing anything to it. It is not likely that the keybed has moved because of the way they are attached. More likely is the action support bolts have bent or ripped out. Check all the screws above, below and at the sides of the key bed. Check the bottom board and the toe screws. Check for tool scars on the capstan wires. Newton
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