Looking at my parts, there is a Hamburg flange with the drop screw about 2 mm proximally located. In your photo, the red leaching of the dye into the shank around the bushing says Renner. My NY S&S shanks have a bushing with a white center not all red. Some Renner flanges (if I'm not mistaken) have the center about 1 mm more distal. The Magic Line is measured with the key set at half-blow not half dip. Half blow is about 1/3 dip and is also the time that the damper engages. The easiest way to measure it is to insert a screw driver blade under the rear of the key until the hammer reaches half-blow. The key end lifter felt height should be about 1 3/8" at rest. If someone replaced the back rail felt and didn't install underfelt then they would have to increase the felt height to time the dampers without drastically lowering the underlevers on the wires (or off them). Check the underlever flange center height while you're at it. The key lifts the underlever to ~1 3/4". Lift one to that height and see if it is parallel to the keybed. I say it should lift to parallel, anything short of that and there is too much sliding friction on the felt and usually causes digging of a trench because the underlevers and at too steep of a downward angle. Lifting beyond parallel is not efficient motion either. There is less scrubbing friction when lifted to parallel. Regards, Jon Page
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