I can’t claim to be the definitive expert in the history of piano making but, for example, the Steinway design is heavy rim, low tension string scale, lightweight assembly, soft hammer. If you change the rim characteristics to lightweight soft rim (as Boesendorfer does) then you necessarily need to change other components. Thus Boes, for example, lightweight rim (spruce), higher tension string scale, heavier assembly, harder hammer (not necessarily in that order). It all really starts with the string scale and all goes together, or should. David Love www.davidlovepianos.com From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of PAULREVENKOJONES at aol.com Sent: Thursday, August 05, 2010 7:52 AM To: pianotech at ptg.org Subject: Re: [pianotech] rcs design considerations David: Correct me if I have misunderstood (I'm sure I needn't say that), but I was under the impression that the rim characteristics didn't play much of a part in panel design. Have I confused this with rib notching into the rim issues? Thanks. Paul In a message dated 8/5/2010 9:38:47 A.M. Central Daylight Time, davidlovepianos at comcast.net writes: Actually on the Boes 9’ piano the panel thickness might even be more like 11 mm, I don’t recall exactly. David Love www.davidlovepianos.com From: David Love [mailto:davidlovepianos at comcast.net] Sent: Thursday, August 05, 2010 7:28 AM To: 'pianotech at ptg.org' Subject: RE: [pianotech] rcs design considerations Boesendorfer, for example, employs a panel thickness of about 10 mm instead of 9 for Steinway for that sized piano (though they also use a less acute grain angle). I typically use 8 mm for smaller Steinways and 9 mm for larger ones. So the question was if you were doing a full RC&S design but the only difference was a soft rim what would you do differently. I’d probably just increase the panel thickness some. I don’t think I’d change the rib dimensions or the other design elements. Ron mentioned beefing up the rim which in effect then changes the rim mass in order to be able to use what would be the same basic design. That’s another approach. I think the question though is given a soft wood rim without altering the mass what changes must be made to accommodate the difference. So what happens then in a soft wood rim that’s different from a hardwood rim and what do you need to do to compensate. Rate of energy loss is one difference. But unless you are going to modify the rim there really are only a couple of choices: change the panel thickness and/or grain angle, change the rib dimensions (RC&S design so you can’t change the EMC at glue up). Bridge height might also be a consideration. I’d probably increase the panel thickness and reconsider the grain angle. David Love www.davidlovepianos.com From: Dale Erwin [mailto:erwinspiano at aol.com] Sent: Wednesday, August 04, 2010 10:00 PM To: davidlovepianos at comcast.net; pianotech at ptg.org Subject: Re: [pianotech] rcs design considerations Thicker than what and how thick is always the question. Thickness is somewhat wood species dependent and any mans best guess. But iahve my opinions about this Gene are you confused yet? Dale S. Erwin www.Erwinspiano.com Ronsen Piano hammers Sales,custom prep and tech support 209-577-8397 209-985-0990 -----Original Message----- From: David Love <davidlovepianos at comcast.net> To: pianotech at ptg.org Sent: Wed, Aug 4, 2010 9:28 pm Subject: Re: [pianotech] rcs design considerations Assuming same scale tensions I would probably use a slightly thicker panel. I don't think I'd alter the rib dimensions. David Love www.davidlovepianos.com <http://www.davidlovepianos.com/> _____ From: "Gene Nelson" <nelsong at intune88.com> Sender: pianotech-bounces at ptg.org Date: Wed, 4 Aug 2010 21:15:19 -0700 To: <pianotech at ptg.org> ReplyTo: pianotech at ptg.org Subject: [pianotech] rcs design considerations Hello list, Just curious: For a typical radius crowned design for a 9ft grand that would go into a Steinway - how would you alter the design if the piano had softwood rim? Would you alter the design? Gene -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100805/a7e9b721/attachment.htm>
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