I was asked to regulate a 1917 Lafargue upright with the relatively rare "Staib-Abendschein Co. Mastertouch" action. This is the one with the wooden arm attached to the hammer butt that grabs the hammer-head shaped jack for "checking" instead of a normal backcheck and catcher. It's the version with a conventional letoff rail, and the flat checking spring rather than the coil. See: http://www.ptgcolumbus.org/files/page_pics_Staib.html Jack Wyatt and Dave Peake have written about this action in the archives, and recently Tom Harr of ptgcolumbus.org posted the nice photos in the link above and the Columbus newsletter, but I didn't see any mention of how to regulate the checking. (Yes, I know you turn the regulating button screw, but which way for what result, and what it the target distance?). It appears to want to check very close, perhaps 3/8ths inch. I say "it wants to", because I found I had little control over checking, other than on/off. It either jambed up before the hammer hit the string, checked wherever it wanted, or didn't check at all. Is it that much of a hair trigger? I must be missing something. Anyone a "Mastertouch" expert? As I found the piano, there was lots of double-striking. Excessive blow, insufficient key dip, lost motion, wide letoff. (Letoff regulation was a breeze with no backchecks to get in the way). Mercifully, it had none of the check flange self-destruction others have found. When setting up a few test notes, I cranked up the capstan to get some aftertouch. In a normal action, I would expect the checking to decrease and perhaps push the hammer to the string as the wippen moves higher. The "Mastertouch" action actually stopped the hammer firmly before reaching the string. I had to get my flashlight and look to see if there was a block of wood between the hammer shank and the damper. That's what it felt like when the hammer stopped. The backcheck arm (for lack of a better term) was grabbing the jack so firmly it stopped the hammer butt as if there was a block of wood in front of it. I screwed in the regulating button on the arm, which raises it away from the jack. That gave the hammer enough freedom to reach the string. But I could not predict how the checking distance would respond to the movement of that button. I just got each note to work and had to be satisfied with that. The action did feel nice when I was done, and seems to have held up very well after 90 years. I would like to know more about it for my next visit. Greg Graham Brodheadsville, PA __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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