David S asked, >What's the dip/blow on the Cristifori? OK. This is getting interesting. I've been doing a little checking around with people who are familiar with the extant Cristofori pianos, and people who've made copies. But, not having any direct experience myself with this type of action, I can only give a partial answer at this point. Promise to follow up later when I've done some more homework. The funny thing about Cristofori is that it's his FIRST action, the one illustrated by Maffei and subsequent publications, which is functionally identical to the modern action. There is a proto-capstan and w(h)ippen, jack, and hammer/butt combination, with the hammers mounted on a rail. I'm not aware of anyone having made one of these actions (Jack W?), and none of the originals is extant. So all we have to go on is the rough sketch in the Maffei documents. Maffei visited with Cristofori in 1709-10, and published an account in 1711, including a diagram and description of the action. [pinches of salt needed here since Maffei was a writer, not an engineer or instrument builder]. The article was re-printed in 1719. Then it made it into a German publication of 1725. So all the historical published stuff about Cristofori's action involved the first version. However..... All the extant pianos (3 of them + a disembowled separated action with no piano) have actions of a different configuration, i.e. Cristofori's SECOND action. This one is different from the modern action. The jack is now mounted on the key, engaging a ledge on an intermediate lever, which remains in contact with the hammer butt throughout the stroke. Escapement occurs by the top of the jack slipping off the ledge of the intermediate lever. Hammer blow is about 35mm on the 1720 and 1722 pianos. On the 1726 piano (the model for the two Sutherland reproductions, and one by Kerstin Schwartz) the extant hammer blow is a mere 24mm. Some people question the correctness of this on the original in Leipzig - thinking it may have been mucked with at some time. But, the action actually functions well with this hammer blow. On the key end, key dip is not an easy dimension to determine accurately and it depends on set up of course - Pollens gives 7mm which is too large. The builders who've worked with this action use a 5mm key dip and the action functions well. As i mentioned before, simple calculation with the lever ratios gives a combined leverage of 10:1 (1:1 for the key, 2:1 for the intermediate lever, 5:1 for the hammer/butt). If this is correct the functional keydip ought to be about 2.5mm, i.e. half what it is. What I can't say at the moment is how the missing 2.5mm keydip is allocated: (i) maybe a little sloppiness in the leather hinges (but that is minimal); (ii) some after-touch, i.e. after escapement touch after the jack has slipped off the ledge of the intermediate lever, and (iii) a little lost motion perhaps in the initial jack/ledge contact. Not having any direct experience with these actions, I can't say how much (i) and (iii) contribute. Will continue to investigate and report back when something definitive comes up. Stephen Stephen Birkett Fortepianos Authentic Reproductions of 18th and 19th Century Pianos 464 Winchester Drive Waterloo, Ontario Canada N2T 1K5 tel: 519-885-2228 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
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