Bob... perhaps I am just off on a bunny trail here... but do I understand correctly that if the string height is optimal for the given action... then both lines of centers are part of the result of the best possible configuration for that action ? Cheers RicB Fred makes an important point that, friction increase or not, there may be some other bad effect to deviating from the line. However, what we're talking about is what to do if the existing string height doesn't allow optimum configuration of the action parts. The most common scenerio I've seen is string height too high. If you maintain the optimum line in this case several things may result: 1. Hammershank swings above parallel to keybed 2. Hammer overcenters at strike 3. Hammershank so high above (nonadjustable) rest felt that the action locks up on certain blows 4. Jack may jam into felt at the back of the rep window 5. Loss of mechanical efficiency Or you can raise the stack, sacrificing the line and: 1. The wippen cushion wears out faster. This is the sort of real life choice that we have to make all the time in action work. What would you do? Bob Hohf
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