---------------------- multipart/related attachment --97.55ec1d18_alt_bound Happy New year Ron Great to hear from you & good of you to remove your head from the piano long enough to post. It's always good to see what's up/new Good Post & enjoyed the design in the pics. Beautiful work. I especially liked the ideas about the beams & belly needing more stiffnes from the maple ones you installed.. This makes a great deal of sense to me. In hind sight what doesn't make sense is so much goes into a fine laminated rim in some American pianos & then the belly rails so weak due to laminated softwoods. This has been in my mind for a while now. I'd truly Like to here the 225 in the picture. After all design is great when the end result produces a sound never/rarely heard before. I should think that a piano so constructed should sustain for a very long time in every register with tonal color to live for. Is this so? Looking at my Mason double A project I notice just how toooo much board is behind the bridge. Its' simply cavernous. It's not to late to put in a fish This has got me thinking again. Is there a percentage of board to remove formula that seems usual? Thanks & Blessings Dale Erwin Terry, Dale and all, >From what can be seen, that grand looks like a pretty well thought out design, with a better distribution of back beams and a generously dimensioned cross beam. And the brand name is? Dale wrote; Buy the way what is the purpose of the wooden block filling in the treble. It looks like it completely eliminated the treble board area or is it the picture? Terry has fitted a treble section cut-off to reduce what I also regard as excessive sound board area behind the bridge in the treble section. If you look at the panel-belly rail contact in the top string section, adequate treble area remains. While it might look to be less than desirable to those who are used to looking at Steinway pianos with the board removed, this piano which Terry has worked on has a main-belly-rail section made from two thicknesses glued together. There's a lot of belly rail acreage underneath that treble section of the board. The belly rail of our 225 piano is similarly constructed, with two 30 mm thicknesses of Rock maple glued together to produce a belly rail which is effectively a 60 mm thick section of solid maple. The entire belly rail assembly in our piano is made from Rock Maple, while the cut-off is made from Australian Antarctic Beech and Silky Beech. An image of 225 piano no.4 with a 60 mm thick main belly rail section can be found at; http://www.overspianos.com.au/ctoff.html With the Steinway D pianos from Hamburg, the belly rail comprises a single 30 mm thick section of Red Beech. I suspect that small total sectional size of this piece is why Steinway glue the key bed to the belly rail, since it will help what I suspect to be an under-engineered belly rail to support the sound board. An image of the '62 Hamburg D case we recently re-boarded can be viewed at; http://www.overspianos.com.au/stdctoff2.jpg A similar treble cut-off to Terry's can be seen fitted to this piano. The laminated bass side corner cut-off reduces considerably the excessive sound board area of the original design, and the resultant 900 + mm middle order ribs will better resist premature collapse. The original laminated sound board cut-off and belly-rail-sound-board-support-beam are made as single bent lamination, which is a good idea. As with Terry's modified sound board area, we left the original cut-off in place since it won't do any harm. Furthermore, it saves us having to insert stiffening sections across the cut-off fill panel. The original D's treble-section belly rail design can be seen better in the following image. http://www.overspianos.com.au/stdctoff1.jpg In addition to the treble cut-off, we have fitted an extra back beam in place of the original 'Steinway bell' to better support both the belly rail and the hitch plate of the iron plate in the top string section. With reference to the image and text below, note the original construction of the belly rail assembly. The lower piece of the original belly rail is the 30 mm thick main belly rail beam of European Red Beech (which is also glued to the keybed of a D). Then there is a 30 mm section of pine or some other light wood (distinguishable in this image by the visible knott). This piece is necessary to allow sufficient room in the action bay for housing the damper levers. This piece is made from Rock Maple in our piano. Above this we see the laminated Maple/Bubinga mahogany piece which supports the sound board across the belly. The most surprising aspect of this design is why Steinway used such a light-weight wood to join the main Red Beech belly rail span to the Maple/Bubinga laminate. Structurally, the belly rail/sound board connection, in all grand pianos, is already at a strength disadvantage when compared to the rim, since there is considerable horizontal offset between the main belly rail member and the belly rail assembly's connection with the sound board. On this list, much justifiable ridicule has been levelled at several pianos of Asian origin for using 'select hardwood' Luaun in the rim, belly rail and back beams. The fill piece of pine in this concert grand would seem not to be any better when it comes to material strength. Could it be that since the pine piece can't be seen in this concert grand once the sound board is installed, that it found its way into the product as a cost cutting measure? Surely not! Happy new year fellow listees, Ron O. --97.55ec1d18_alt_bound An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/a2/39/da/58/attachment.htm --97.55ec1d18_alt_bound-- ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 73082 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/6c/7c/22/2d/attachment.jpe ---------------------- multipart/related attachment--
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