William A couple of ideas you might want to try 1. Sand the bottom of the tail, and take the edge off. Got this advice from Kent S. and it worked on quite a few hammers on a S&S 2. Check the balancier pinning. Remove the spring, and feel the lever. There should not be any resistance. 3. Does increasing or decreasing the check distance do anything at all, or does it still bounce? Wim -----Original Message----- From: William Monroe <bill at a440piano.net> To: pianotech <pianotech at ptg.org> Sent: Thu, Jul 29, 2010 3:19 pm Subject: [pianotech] Bouncing Bostons Hi List, Anyone know of anything chronic in Boston Grands (GP178) that has the hammer double striking on a quick/firm staccato blow? I've got one that does. Anyone have any ideas/solutions? The piano is finely regulated otherwise (just today, in fact). 1 3/4" blow, about .400" Key Travel, Checking about 1/2", Rep springs are definitely NOT jumpy. In all other ways, the action plays nicely, controllably. And that is no mean feat. I took some DW/UW measures today out of curiousity, and they were haywire. DW range from 62g - 46g, UW from 18g to 35g or so. My thoughts are turning to action pinning (haven't checked yet). Key Bushings and pins are clean and lubed (teflon), but that's as far as we got. Wondering if tight pinning (of any parts) might contribute to this rebounding back into the strings - and it is a full rebound. You can watch the hammer appear to bounce off the rest rail, though I'm not convinced that is exactly what is happening. Kind of musing aloud here.............. William R. Monroe -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100729/faa46b4c/attachment.htm>
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