Bill Ballard wrote: > > 1.) If you're really interested in where "excess" inertia would be > more objectionable, the key of the top action, the objection would be > how each component accelerated. That would imply that it's possible > to detect, in an action where inertia makes acceleration increasingly > more expensive. which component's acceleration is suffering from > inertia. Dont you think that it is possible to identify this in some meaningfull sense ? > Certainly we have David Stanwood's static tests and > guidelines to to answer that question from a technician's standpoint. Davids tests can create a situation where key to key inertia is very much alike...gradually becomming less and less from bass to treble. But it doesnt address inertia directly in any other sense... Indeed... it would seem it does not consider any other aspect of inertia to be of importance aside from what a given overall SWratio itself results in... and that regardless of hammer weight or component leverage contribution. > > But show me a pianist who can accurately determine by feel, which > component has the excess inertia. Accurately determine which component has excess inertia ?? why would they want to directly... but it may be possible for technicians to determine component combinations that typically result in pianists complaining of specific inertia problems. > I mean, a key of average inertia > with a top action of excessive inertia sitting on top of it probably > behaves no differently than a high inertia key with a normal top > action sitting on it. In the former, the key is ready to accelerate > as easily as we'd want, but its motion is is restrained by the > sluggish top action load. In the latter, the top action is ready to > accelerate as fast as we'd want, but its motion is provided solely by > the key underneath it which will always be too slow. And you mean to say that these two conditions would feel more of less the same ? What justification do you have for that ?? I mean have you experimented with this directly... or is it more supposition ? An interesting experiment me thinks.... > 2.) Ric, you make it sound as if the choice we're making is a matter > of a trade-off, say between where in a given scenario we'd prefer our > inertia, the Lady or the Tiger. (Me, I'd much rather the tiger was > overweight and slow to accelerate. <g>). But show me the practical > situation where a given action would have these two ways to set > itself up, and be otherwise indistinguishable except for the location > of the excess inertia. Well.. I dont mean to make it sound like anything in particular... I am wondering about it all... As for your challange.... that would seem to be at the core of my questioning... your response goes along the lines that it does not matter how much inertia is where. Others seem to be pointing at the top action, and much has been made of the need to reduce key leads to near nothing. Like I said.. I am fishing for things to provoke my own thinking along these lines. I have to re-read your first reply... as it seems you are going in the opposite direction here... perhaps because you have narrowed more closely in on what I was thinking about when I asked the question ?? > There are two ways to up the inertia of a key, adding weight to one > side and adding weight to both sides. The former (normally referred > to increasing the FW), if done to excess in an action with a normal > Top Action Weight, will quickly render the action unplayable with Up > Weights in the 5g range. So in posing this question you must have had > in mind adding weight to both sides of the key, which *will* leave BW > untouched. But show me the practical situation where there was a > normal top action weight sitting on the capstan, and one had reason > to increase the weight on both sides of the key, to the point of > excess. This seems to hint at pianists not being able to sense inertia of the upper action except as it is defined as the opposite to FW... which seems to point very much in the direction of a static sensation and not inertial. In anycase... have we really established that same overall inertial levels feel the same regardless of the levels of the individual component parts ? Sounds like you are saying the overall action ratio can be seen only in terms of some kind of effective key inertia concept. > > > Ric, now that every has dumped all this stuff into one big heap, we > could help pick through it better if you told us what you were > thinking when you phrased this question. Nah.. you'll get there quick enough.... if you havent already read my mind.... So far the whole discussion has been great... lots of good things to put into perspective. Thanks muchly. > > Bill Ballard RPT > NH Chapter, P.T.G. > -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html http://www.hf.uib.no/grieg/personer/cv_RB.html
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