<html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; = charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> Hi Dave:       =       I fail to see how pressing the damper pedal would affect the checking of = the hammers. If you press a = key slowly, does the backcheck get close enough to the hammer butt  to = touch it, and (hopefully) to catch it on the rebound?  How far from the = string is the hammer when it checks?  Sometimes the checking distance is = too close to the string.  Be sure, also, to adjust the lost = motion.  Too much will prevent the proper checking action, the same as insufficient = dip.        =       The leverages are already set by the design of the action.  It is the = travel (movement) of the parts, and the distances involved that allows the = action to do what it is designed to do.  (Assuming the parts themselves are = not damaged, worn out, loose, or stuck).  There are two things that = need to happen for the hammer to check.  The jack must clear the butt, and = the backcheck /whippen /hammer butt need to come into contact.  = Even if you have = aftertouch, still, other things can affect the checking.  The Mason I was = working on had aftertouch, and seemed to play correctly, but for want of sufficient = dip, was not working to its optimum.  A little more dip made the world = of difference.  It is my experience that the Chinese pianos sometimes = aren’t regulated to my liking.  Although they may work, often they need = better regulation.  This may entail raising the center rail, leveling = keys, shimming the hammer rail, bending the backcheck wires, =  whatever.          =       Let me (us) know if adding more aftertouch (dip or shorter blow distance) = does the trick.        =       Paul McCloud       =       San Diego           -----Original = Message----- From: = pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Piannaman@aol.com Sent: Saturday, December 06, 2003 8:54 AM To: pianotech@ptg.org Subject: Re: Story and = Clark/QRS console bubbling hammers   Hi Paul, Thanks for the advice.  There is plenty of aftertouch.  That = was one of the first things I checked and corrected, because initially, there = was none.  Everything works fine--until the damper pedal is engaged. I will put some thicker punchings on a few balance rail samples and see = if it can be regulated properly before I raise the whole rail.  Could it = be a leverage issue??   Dave Stahl In a message dated 12/6/03 8:29:10 AM Pacific Standard Time, pmc033@earthlink.net writes:   &nbsp= ;        You need to determine if there’s enough aftertouch.  As you go = through let-off and the key bottoms out, check to see if there is a little = forward motion of the hammer, and that the jack it out from under the hammer = butt.  If not, your key dip is still too shallow.  Putting a thinner punching may get you closer to the correct dip, but you need to be more = precise with this adjustment.  Setting the letoff point will help some, but = you must be sure that you have enough dip to make it work.  I recently = worked on a Mason Hamlin large upright which had a similar problem with = bobbling hammers.  Actually it wasn’t so much bobbling, but the piano = had a kind of “loose” feel.  By raising the balance rail, the = dip increased and the checking worked much better.  Hope this = helps.   &nbsp= ;        Paul McCloud   &nbsp= ;        San Diego =   </div> </body> </html>