Definition---de regueur--required by current fashion or custom. New one to me Dale -----Original Message----- From: David Love <davidlovepianos at comcast.net> To: pianotech at ptg.org Sent: Thu, Jan 14, 2010 7:33 pm Subject: Re: [pianotech] Action Ratios Recap My practical question may have been unclear to you but when I put this uestion (If you are constructing an action and want one that regulates with 0 mm total dip and 46 mm blow where should you target the action ratio?) to he individual who manufactures replacement keysets for me he was able to ive me a fairly precise answer with some slight variations depending on the articular action model. Your description of after touch below is, of ourse, de rigueur. David Love ww.davidlovepianos.com ----Original Message----- rom: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf f John Delacour ent: Thursday, January 14, 2010 6:13 PM o: pianotech at ptg.org ubject: Re: [pianotech] Action Ratios Recap At 16:08 -0800 14/1/10, Jason Kanter wrote: >John, the same day of your detailed and interesting message, David Love asked you: OK. So then from a practical standpoint, when converting action ratios as calculated by a product of levers to the relationship between dip and the requisite hammer rise to achieve a targeted blow distance with adequate aftertouch, what would you use? Well the reason I didn't answer this is because it made little sense o me no matter which way I turned it. There is one way and one way nly to perform these calculations accurately and that is to use rigonometry. What a "product of levers" means is not clear, but here is no way (and no point) to convert something based on a alsehood into a correct result. As to the after-touch, the key must go down far enough after scapement commences to allow the roller (knuckle) to clear the face f the jack as the hammer falls into check, as is common knowledge. t that point the back of the jack is touching but not compressing he cushion. Any further after-touch is unnecessary and detrimental. he tail of the jack rolls and slides on the set-off button -- as ith the roller/jack contact there is inavoidable friction, but the xact distance the key must travel to accomplish this optimal scapement can be accurately calculated trigonometrically just like ll the other relationships. and I asked you: John, could you please add a definition of PROFILE? Though the answer was included in the message that asked the uestion, I have made it clear in a separate message. JD = -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100114/6232d0c2/attachment-0001.htm>
This PTG archive page provided courtesy of Moy Piano Service, LLC