Hi All, A player piano came into the shop that was constructed with
upper plate bolts which pass completely through the pin block and
frame. The nut is countersunk into the back and is not accessible.
After removing the cap from the pin block, I couldn't help but notice
the open space (approx. 3/32") between the pin block and the frame.
Over the past few days, I've been carefully tightening the bolts about
1/2 of a turn per day. Slowly, the crack is closing, and thus far there
haven't been any strange noises. If the current state of affairs
continues on its present course, the crack will be completely closed
within a few more days. This leads me to my question:
What is the correct amount of torque that should be applied to the
upper plate bolts? Right now, the applied torque is 30 ft.-Bs., but
the crack is still visible (approx 0.060" wide).
John A. Tuttle