I have just checked, and the "hump" is consistant from bass to treble. Larry Messerly, RPT Prescott,AZ > I'm no expert on piano designs, but you could likely tell pretty > clearly by > using a nice 4-foot straight edge and laying it across the keybed in > the > back, in the middle, and across the front, and then also from front > to back > (as you apparently did) in the middle and at the two ends. I should > think > that if it were designed, the curve/bow/whatever should be regular, > i.e. the > whole front would be curved down, or something like that. > > I'll bet that either the front of your keybed has sagged in the > middle, or > the middle portion (front to back and side to side) has bowed up. I > can't > imagine anyone designing a sag in the front center, or a bump in the > middle! > > Sounds like a good thing you have a flexible keyframe! Don't bother > wasting > time with bench regulation! > > I like to do my rough regulation on the bench, so I always take my > key > leveling stick and check out the keybed - just to make sure it is > pretty > planar. That way I know I can come close on the bench. I find that > if the > keybed is real planar, and you have a real flat planar regulating > table (not > easy to get without making sure it is planar), I can come real close > to the > final regulation on the bench. If the keybed is all warped, forget > the > bench - maybe forget the piano! > > Terry Farrell > Piano Tuning & Service > Tampa, Florida > mfarrel2@tampabay.rr.com > > ----- Original Message ----- > From: "Larry J Messerly" <prescottpiano@juno.com> > To: <pianotech@ptg.org> > Sent: Sunday, February 18, 2001 2:19 PM > Subject: Crown in Key Bed > > > > I am presently working on a Kranich and Bach that appears to have > a > > one-eitghth inch crown in the key bed. (Using a straight edge > held down > > at the back of the key bed, it is 1/4 inch off the keybed at the > front.) > > > > Is this the way the piano was designed or is this damage of some > kind? > > > > The key frame is VERY flexible in that when it is removed, the > front rail > > can easily wave in the breeze. > > > > Larry Messerly, RPT > > Prescott, AZ > > >
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