---------------------- multipart/alternative attachment I don't have an angled keyboard for inspection at the moment but I can provide a speculative reply. If the keys are shorter in the treble, the balance rail is also set at a corresponding angle. This will still provide a similar Key Ratio proportionally so a different height heel would not be needed necessarily. The bass and treble hammers (1 & 88) generally have weight difference of 6 to 7 grams. I don't see where the lighter treble hammers need the advantage of a long keystick. To have the keys equal length on certain pianos would alter case dimensions and overall athetics with little or no performance benefit, seems to me. The problems I see are in the action setup on the production line. I think that errors are overlooked and the action designer's parameters are compromised for the sake of production. Generally by placing the capstan in what I consider a proper attitude I have corrected geometry/regulation maladies. The ideal capstan location I have found is where the capstan/cushion contact point at half-blow is renewed or maintained but the angle of the capstan in the keystick is 90 degrees to the cushion at half-blow. This allows the capstan and whippen 'line of centers' to be equal and opposite from rest to letoff. Many times all that is needed is the angle of the capstan altered and maintain the same contact point. So on the production line the capstan was installed at an incorrect angle and subsequent regulation suffered. There are actions which have the capstan in the wrong location for the simple reason of keeping it centered on the whippen cushion (as you mention below); this production oversight is a welcome correction by the piano owner and they invariably ask, "Why did they not correct this?" Pointing out that some company's PR is better than their Quality Control I say, "Someone, somewhere will like it and buy it; 'they're supposed to be heavy' is either their filling market requests or conditioning the market for production failures." End gripe, Jon Page At 06:38 PM 12/09/2000 +1100, you wrote: >To those commentators on piano design, and other interested lurkers, > >While it is generally accepted that the hammer strike line should be >parallel to the front of the key bed for smaller grands, the situation is >not so universally accepted for longer pianos. > >I have raised this issue with piano designers over the years and there is >some variance of opinion. Obviously, a shortened treble layout will >position the treble tuning pins closer to the tuner (this may certainly be >an issue for a 3 metre piano), but is this the primary reason for >shortening the treble end keys, and what are the negative outcomes of such >a design regime? > >Recently, one designer claimed that shorter keys are necessary in the >treble for the tone. He claimed that the resultant stiffer treble keys (of >the angled strike-line pianos) assist with the feel of a 'crisp' treble. I >remain a sceptic, since the hammer mass is less in the treble. Therefore >the treble keys should appear to be relatively stiffer than those of the >bass (even if they are of the same length and depth), since note C88 will >be lifting a hammer which is often 40% lighter than the first bass hammer. > >Kawai, Fazioli, Steinway and Yamaha all shorten their treble end >concert-piano key lengths (by as much as 75mm or 3"), while Bosendorfer >persist with a non-angled strike in their 9'6" Imperial model. Certainly >an angled-strike regime complicates the geometry setup for the wippen >heels (most, if not all angled-strike adherents, seem not to make any >adjustments). Ideally, when the strike is angled, the wippen heel depth >should be greater for the shorter treble keys (if the contact between the >capstan and heel is to remain on the fulcrum line at half dip). Therefore, >if we are to produce wippens with idealised heel dimensions from bass to >treble, for angled-strike-line pianos, the heels should vary in height >from bass to treble accordingly. Such a heel set could be made from a >specially tapered piece of stock prior to sawing them to width. When the >strike line is parallel, no such geometry problems are encountered. While >a parallel strike will place the treble tuning pins some distance away >from the tuner (as already mentioned), the extreme treble is more likely >to have a smaller sound board area between the bridge and the adjacent >outer rim - a desirable design objective I would think. Some might >consider using a greater dead-string-length between the capo bar and the >tuning pins as a solution with the parallel-strike design, but excessive >length here would surely encourage rendering and tuning stability problems. > >Your views I await. > >Ron O >-- > >_________________________ > >Website: http://www.overspianos.com.au >Email: mailto:ron@overspianos.com.au >_________________________ Jon Page, piano technician Harwich Port, Cape Cod, Mass. mailto:jonpage@mediaone.net ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/db/b5/44/16/attachment.htm ---------------------- multipart/alternative attachment--
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