This is a multi-part message in MIME format. ---------------------- multipart/mixed attachment Inertia Heads, The next step toward understanding how the action works when actually played is to find the total MOI as measured at the front of the key. First we need to find the MOI of the key, wippen and shank. I thought it would be useful to find ways to estimate this. The drawing shows a way to estimate the MOI of the key. I have ways to estimate the MOI of the wip and the hammer/shank as well but first I wanted to se if anyone else had ideas on how to do this. We could use a variety of methods to measure the MOI directly like using a torsion table or torsion pendulum. But these are difficult to build and calibrate, more useful for demonstrating the principles of inertia than for getting accurate measurement. Professional measuring equipment is beyond my reach so for now the estimated MOI will have to do. After finding the MOI of the three parts the total MOI can be figured with an equation. John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015] ---------------------- multipart/mixed attachment A non-text attachment was scrubbed... Name: MOI-of-key.jpg Type: image/jpeg Size: 27427 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/86/ca/f5/24/MOI-of-key.jpg ---------------------- multipart/mixed attachment--
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