<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> Dave:       =       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.       =       Paul McCloud       =       San Diego   -----Original = Message----- From: = pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Piannaman@aol.com Sent: Friday, December = 05, 2003 7:46 PM To: pianotech@ptg.org Subject: Story and = Clark/QRS console bubbling hammers   Hello again, It's been a week for pain-in-the-posterior piano problems.  A = couple of months ago, I was called to come and see if I could figure out and fix a problem with bubbling hammers on a Story and Clark console piano with = QRS pianomation installed.  When I got there, almost every hammer was bubbling.  Key height was fine, but the dip was way to shallow. =  I replaced the fat front rail felt punchings with more meager ones, did a = bit of regulation, and the problem was gone...at least for the time being. I got a call from the lady a couple of weeks ago complaining of a few = more bubbling hammers.  I got a chance to go out yesterday, and with a = small amount of let-off adjustment on a few notes the problem seemed to be cured--until I pushed the sustain pedal down.  I could not make all = of the hammers check when the sustain pedal was engaged. Can anyone tell me if there is some connection between pedal/damper = function and the QRS mechanism?  It doesn't seem as though there should be, = but I have never installed or worked on one of these. The problem seems to be that when the sustain pedal is down and the = dampers up, there is not enough strength in the springs to push the hammers back = quickly enough to catch on the backchecks.   My thought is to check the tightness of the whippen and hammer centers.  The action feels far more sluggish than it did the first time I = worked on it.  I suspect moisture or something else has invaded the bushings.  Maybe graphite coated center pins???  I certainly hope not.  Been there before. Any thoughts or recommendations for possible courses of action would be appreciated. Thanks again! Dave Stahl </div> </body> </html>