On May 27, 2010, at 8:54 AM, Paul T Williams wrote: > The key level and dip is factory perfect, I've got the proper blow > distance of 1.75". I can't get let off any closer than 1/4"!! The > rebuild was done right and the plate is the same height as before. > I've even tried to raise the blow a bit, and still can't get it to > let off correctly. Hi Paul, Just a quick comment here, on what may seem to be a side issue, but it is pretty fundamental to my way of thinking. I always start with letoff. It is the one thing that is not negotiable. Blow and dip are then established to allow for enough aftertouch. Blow and dip figures are a good starting point for roughing in, but they are both very much negotiable. The standards, particularly for dip, are not really as precise as they seem. When you see how people actually use the dip block, ask questions, and analyze, you find that in most factories the block is slightly below the neighboring keys - you are feeling for a slight and even "edge" between the block and the neighboring key - and the block is held very sensitively and lightly so as not to compress the front punching felt. Compression of the felt is taken into account for aftertouch. Bottom line, one person's 10 mm dip (light touch, slightly below neighboring keys) may be 10.5 or more for someone else (heavy touch and even with neighboring keys - I think most piano techs press down too hard). And dip is probably lowest on the totem pole when it comes to regulation specs (though an even aftertouch is right behind letoff - dip must be set precisely and consistently). And blow is certainly negotiable within 2-3 mm if not more. If you can't get enough aftertouch, add 0.1 mm to dip, then 0.2 mm, then subtract 1 mm blow, etc. This doesn't address your question directly, but maybe it will help in bringing the problem into better organization and focus. I have found that I can get virtually any piano I have faced into an acceptable regulation without resorting to geometry changes (unless changes have already been made by someone else who didn't know what he was doing). Sometimes with new parts I will need to change drop cushion felt/leather or letoff button thickness to get the regulation I want (physical limitations of the screws' movement), and sometimes the tails are too short and the checks can't really be raised enough for decent check (20 - 30 years ago Steinway - raise them and you have problems with shoulder felt bouncing on the checks at rest in the tenor), but otherwise a decent compromise can generally be found, or at least that is my experience. Regards, Fred Sturm fssturm at unm.edu "I am only interested in music that is better than it can be played." Schnabel -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20100528/21e6fc26/attachment.htm>
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