I have a question about tight afraffes, relating to a Steinway grand I recently encountered. These agraffes have broken; and, their posts will not come out by any means thus far tried. Professional machinists whom I have consulted can't budge them either. Now what? J R W -----Original Message----- From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of reggaepass@aol.com Sent: Tuesday, November 15, 2005 9:37 AM To: pianotech@ptg.org Subject: Re: Agraff Torque Hi Paul, Agraffes should be snug, and (in our experience) can be cinched down at least 1/4 turn after contact in the interest of proper alignment (to a thread running through the corresponding bridge pins). We use both the washers and the mill to smooth out the level of the agraffes, in the interest of having as consistent a string plane (from unison to unison) as possible. Attention to this detail (among many others!) helps the action regulate more evenly. If you are curious about how much torque an agraffe can take before it snaps, slather the threads of an extra one up with lithium grease, spin it down to the point of contact, and then continue to gradually turn it down....until it breaks. (The lithium grease makes it very easy to get the broken agraffe post out of the plate.) If you try this exercise, your hands will know what it feels like as an agraffe weakens and when it breaks. There ARE many mysteries in life and piano work, but knowing when an agraffe is properly seated without going too far needn't be one of them. Alan Eder, RPT California Institute of the Arts -----Original Message----- From: Dempsey Jr., Paul E <dempsey@marshall.edu> To: Pianotech <pianotech@ptg.org> Cc: caut@ptg.org Sent: Tue, 15 Nov 2005 09:52:36 -0500 Subject: Agraff Torque Lists, I've had the occasion recently to install new agraffs in a big Baldwin I'm rebuilding and a question comes to mind I'd like toss out. The agraffs I removed were surprisingly easy to get out. Almost as if they were not really tight to start with or perhaps they loosened after installation. I guess my question is how tight do these need to be torqued down.what's the rule? And, as the thing approaches the "appropriate" tightness, and, the alignment is off several degrees, which is the better approach..the little washers or using a hollow mill. Clearly, there is a little gap in my knowledge/skills, agraff wise. Your wisdom is appreciated. Thanks Paul E. Dempsey, RPT Piano Technician Sr. Marshall University Huntington, WV 304-696-5418 304-617-1149 _______________________________________________ pianotech list info: https://www.moypiano.com/resources/#archives
This PTG archive page provided courtesy of Moy Piano Service, LLC