I set up my spread sheet a few years ago and did it originally all from Robert's book. Since then it's gone through some iterations and to be honest I don't now recall whose formula is on there. Once I get them onto the spread sheet the formulas have a way of disappearing from my consciousness. I do different things with respect to rib arrays. All projects employ bass cutoff bars. I generally install straight ones as they're easier to clamp when you don't want to cut the board, which I don't. They all connect to the belly rail in about the same spot somewhere around note 50 and shorten the longest ribs lower in the rib scale to around 800 - 850 mm. Some have a treble fish and some don't. I don't always lay in a new rib array but if I do it's radialized. The two projects pictured use the original rib locations. I don't know what a "Z bar" is. At least not by that name. I've gone back and forth between new and original rib locations depending on the customer's goals (new rib arrays cost more), and also to explore select variable changes as a mode of comparison. As Ron mentioned what would be really nice is to get 5 or 6 of the same piano and do a sequence where you change select variables to see what happens and give you side by side comparison. This job could be so much more fun if we didn't have to worry about making money doing it. To copy a chart to email (with a PC), open the excel spread sheet and open the new email. Go to the excel sheet and click on the chart, hit Ctrl C to copy the chart (or anything else for that matter--keyboard shortcut). Go to the email put the curser on the email where you want the chart to appear and hit Ctrl V to copy. Very easy. Don't know on a Mac. You need to be in HTML format which means the chart wont get into the archives. Wont work in plain text. BTW, heres the latest scale iteration (Steinway L) having had to make a few concessions on the long bridge down in the tenor section. You can kind of play with these things forever but at some point you do actually have to make a decision and build it. David Love www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Jude Reveley (Absolute Piano) Sent: Thursday, May 28, 2009 11:17 AM To: pianotech at ptg.org Subject: Re: [pianotech] Modified L Scale with 5 note transition Here are the two versions I'm aware of: Z=(d²NLf)/.02078 published by Jim Hayes Z=d(NT(1+B))^0.5 published by Dave Roberts Nice work David. I like your approach to the transitions, although like so much else I would love to hear it to know for sure. This shape is very classic (Hallet & Davis did this but added wound trichords instead of bichords. I've got a few in the oven so I should have a better idea soon. My first transitional bridge was on my first RC&S project that Ron Nossamon designed for me about a year and a half ago. It's definitely an exponentially better piano than anything I've ever done in that class and turned me on to this wonderful world. Thanks Ron. Are you throwing in Z-bars and radial rib arrays on all the pianos you add transitions too? I've asked this a few times before, but what version of calculating inharmonicity are you all using? Finally, how do you attach a graph onto an email? Jude Reveley, RPT Absolute Piano Restoration, LLC Lowell, Massachusetts (978) 323-4545 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090529/a41555e3/attachment-0001.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/png Size: 58969 bytes Desc: not available URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090529/a41555e3/attachment-0001.png>
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