|
Often times, the center pin bushing cloth is treated with a certain chemical from manufacturer which may cause increased centerpin-bushing friction through time and usage. Re-pinning helps prevent this problem. Before the re-pinning procedure, place hammer shanks in the order of the thickness, the thickest to the bass and the thinnest to the treble. The package from manufacturers usually indicates that the shanks come in different sizes or of the same size. We use one or two flanges as samples to figure out how the whole procedure shall be performed. Push out the original center pin, measure its thickness. Pick the replacement pins one size larger. Here, the original pins are size #20=[(50-10)/2]. Size #20-1/2 pins will be the replacements. Use the reamer for size #20-1/2 pins to gently ream the two bushings at the end of the hammer shank, push a new pin into the bushing, feel the friction or tightness. It should have some resistance. Ream more if needed. Keep in mind that aggressive reaming may enlarge the bushed hole too much and it is not reversable. Push in the new pin to connect the shank and the flange. Leave the pin protruding on both sides. Check friction. According to Renner USA, the hammer flange center pin friction is between 2 and 5 grams, more on the bass and less on the treble. Clip off the protruding portion on both sides. The clipped surface creates a mushroom like shape which will lock the pin inside or prevent it from walking out. Now the procedure, how much to ream, and the new pin size are determined. Remove all flanges and go to town. The whole process takes up to 4 hours according to Randy Porter's "G" Piano Works Repair Labor Guide. When finished, number the shanks and place back to the package to be used in the future. Close the box and mark that this set is re-pinned.
Comments are closed.
|
