Phillip L Ford wrote: > One case I > neglected to examine was the case of a closed face pinblock with tuning > pin bushings. Assuming that the bushings are truly effective, then the pin > bending in this case should be no more than for an open face pinblock > arrangement. In which case, the closed face design with tuning pin bushings > would have the lowest deflection (would be the stiffest) of all. Several good ideas have appeared on this list about ways to make bushings more effective, and all of them at least mitigate the flex of the pin to some degree. However, if we are trying to make bushings into vertical extensions of the pin block, which in my opinion is the objective, then they fail miserably. In some cases they are little more than a means of centering the drill bit, and some users don't claim any different. The best way to make a vertical extension of the pin block is to remove that area of the plate and raise the block. > Why do you want to discourage tightening a pin by driving it further > into the block? Driving the pin further tightens it at the bottom, which is where loose pins least need tightening. It might prevent them from slipping for awhile longer, but there will still be too much looseness and play at the top. To some extent it also changes the string geometry and bearing friction, and makes them inconsistent with their neighbors. Paul
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