This is a multi-part message in MIME format. ---------------------- multipart/related attachment ------=_NextPart_001_001F_01C14695.B1CD7CB0 At 08:48 26/09/01 +1000, Overs Pianos wrote: Is this the action. Thanks for sending this to the list Clarke. I did say, in the message you quote, that this is of course NOT the = action. This is the one: J L R C H In the Herrburger lever JL is 70, LC is 69, LR is 9.5 and R is almost in = line with LC. JC is 50. LH is 47, CH is 30. The jack tender makes contact 26 mm from = C, 4 mm above the line LC produced. John, would you mind explaining the letter diagram you have used above, = just to avoid confusion. Thanks. J =3D Jack corner (=3Dknife cut on rep lever) L =3D Intermediate lever centre R =3D Repetition lever centre C =3D Jack centre H =3D Mid-point of lever heel supposing it is 8, then reducing LC to 75, as you have done, will = diminish this figure and reducing it to 69 as Herrburger did will diminish it further How? You wrote "...the roller/knuckle contact scrubs badly since the contact = is around 8 mm below the line of centers at the rest position." Have I not understood you? You are talking of the line from hammer = centre to lever centre I understood. If we take a hypothetical set-up = with a 50 mm jack at a given angle, a horizontal line from lever centre = to jack centre (whether 99 or 75 or 69) and a given vertical distance = from this line to the hammer centre, and a line AB from hammer centre to = lever centre, then a) the closer the lever centre approaches to the jack centre, the = shorter the distance of the contact point below the line AB. b) the smaller the roller , the shorter the distance of the contact = point below the line AB. That's all I'm saying. In practice the line from lever centre to jack centre at rest is rarely = horizontal. What I am saying is that you have reduced the length of this line to 75 = and Herrburger reduced it to 69; both you and Herrburger use the older 9 = mm roller rather than the current 10 mm roller and there are good = reasons for these choices. I have not yet investigated the geometry of = your action and it's probably 20 years since I investigated the = Herrburger action, but there is no doubt that either is preferable to = any currently used version of the Erard-Herz action. I do doubt though = whether your version is significantly better than Herrburger's if at = all. When I have time, I'd like to make drawings to make a proper = comparison. I have a question about your angled lever heel/capstan block, which = looks that same as an arrangement patented by Grotrian in 1905. I see = no rationale for this and Pfeiffer says of it "..the point of view on = which the patent was based is not to be upheld." It looks to me also as = if this arrangement makes even more fiddly the process of adjusting the = capstan screw. JD ------=_NextPart_001_001F_01C14695.B1CD7CB0 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/c4/29/23/ca/attachment.htm ------=_NextPart_001_001F_01C14695.B1CD7CB0-- ---------------------- multipart/related attachment A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 13484 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/75/c7/02/15/attachment.gif ---------------------- multipart/related attachment--
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