---------------------- multipart/alternative attachment Stephen and list, Stephen wrote; >I'm curious: what would be the adverse effects of having trichords >below C28 in a spinet? Many pianos that size I see have the >trichords down to G35 or F33 or around there. And a much better idea it is too! Percentage of breaking strain!!!!! Just measure any short piano scale (upright or grand) and set it up on a spreadsheet to check out the deviation (often 70-24%) of the percentage of breaking strain (%brk). Then do the same for any concert piano from Kawai, Yamaha or Steinway. It doesn't matter which one you measure since their scales are almost identical, eg. F21 speaking length - 183 cm (72"). 'We're all individuals'. The %brk deviation (70-45%) of the concert pianos is much less, and as you would expect, the tuning stability is much better. I'm not suggesting that 183 cm speaking length at F21 is ideal (or that F21 is the ideal 275-piano break note for that matter). In fact, I believe there remain considerable improvements to be had with the current scaling of concert pianos also. However, far and away the biggest scaling disasters are the shortest. This need not be so. I have a scale for our own 121 cm upright piano (still at the drawing stage) which has a %brk deviation of 70%-46%. Next August I will commence work on the manufacture of our own 170 cm grand piano. This piano with a %brk of 46% for the lowest note on the long bridge, should exhibit marginally better tuning stability than the current crop of 274-8 concert pianos. I cannot abide scales which were obviously designed as a 'fashion statement', or should I say an 'ostrich statement' (which currently is most). Just because 'piano X has a break here, we'd better follow suit'. Why on earth do we need to be so stupid? Remember that PR people are just that, they know nothing about piano design. Too often we let them 'call the shots'. If running a bridge out so far, it practically 'sits on' the inner rim is flawed, don't let the PR folks dictate just to get a big speaking length number into the brochure. After all, pianos are made for listening pleasure. Broaden the possibilities and be prepared to argue, discuss and assess design possibilities. We're living in a computer age. Open a spreadsheet and use it. It's a wonderful analysis tool - but keep listening too. Numbers alone don't mean much. Recently on the list Dave Nereson mentioned down bearing vector forces per string on the bridge of around seven pounds (he wouldn't be too far out if he was referring to the set up of some Bosendorfer pianos, which are relatively high - but a more common figure might be around 4 lbs per unison string). Get out the spreadsheet again - take Ron N's lead. Write in the simple formulae for tension and down bearing. Find out the facts. Don't take anybody's word for anything. It's a great time to be alive. Regards to all, Ron O -- _________________________ Website: http://www.overspianos.com.au Email: mailto:ron@overspianos.com.au _________________________ ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/92/a9/63/59/attachment.htm ---------------------- multipart/alternative attachment--
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