The casting of plates vary so you will need to locate the optimum location of the top three sections. Sort the shanks according to the tightness of the pinning, tighter ones in the bass and the looser ones in the treble. Bore the hammers to that one piano and add only about .5 mm more (but no more than) to the bore distance than the piano calls for. (The difference between string height and hammer pin height) Use Spurlock's tapering jig to taper the hammers from strike point to tail tip, two or three thou of the strike point and about 0.060" off the tail (each side). Weigh the hammers to see where they lie along the weight chart provided by David Stanwood. First, normal distance (on an S&S) is 5.125" (use a caliper) so start there with the two end hammers of each of the three top sections. Cut the shank to leave just about 1/16" sticking out of the back of the hammer. Spit on the shank or blow the same substance into the hole and put the two together. You will be able to move them back and forth (hold the shank VERY firmly) When you have the best possible sound carefully check the verticality of the hammer and that the molding is 90 degrees to the shank and that it is nicely traveled. When all is perfect put some accelerator on the inside of the shank/molding and put some thin CA on the stub of the shank. The moisture inside the hole will help cure the CA and the accelerator will prevent it running down the shank just in case it doesn't. Hang the rest at 5.125". If this is an S&S of course. If it is another then follow your instincts and training. On Masons and Bechsteins the hammers are NOT hung at 90 degrees to the shank. The Mason the strike point is tilted 1 degree towards the keys and the Bechstein only God and the assembler knows what and why. After the hammers are hung then you can take off the ends of the shanks and shape the tail by using a disk sander and a 2.5" radius. Do each one, one at a time and before screwing back onto the rail check the pinning. You will not be stressing pinning again so this should be the final pinning. Have fun.
This PTG archive page provided courtesy of Moy Piano Service, LLC