----------------------------- Newton Hunt wrote: > "Why the 7º angle on the tuning pins?" > > In a grand piano the angle for drilling a pin block is determined by the > height of the bearing bar such that the pin is at 90 degrees to the > string when the bottom coil is 1/8" from the plate. I prefer about 4.0 mm (approx. 0.16"), but yes, that's my point. I like to have the string leaving the pin with an "up" angle of between 0.5º and 1.0º. But almost never does this add up to a 7º tuning pin bore angle. Consider the tenor section of a Steinway B, for example. When I started actually measuring these things I found that the tuning pin bore angle should probably be more like 1º to 3º in most grands. And about 0.5º to 2º in most vertical tenor/treble sections. Somewhat more in the bass sections of each. > In a vertical piano this is complicated by the unknown height (unless > carefully measured before hand) of the pressure bar when assembly and > tuning is complete. In most vertical pianos the V-bar height is "correct" when the string is parallel to the surface of the plate with the tuning pin driven in and with the string approximately 4.0 mm from the plate surface. There are exceptions. Measure. Measure. Measure. > If the angles are wrong the string will tend to want to ride down the > pin or ride over the next coil up. So, let's keep those angles down, boys and girls. Regards, Del
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