<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2600.0" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT size=2>This discussion is becoming a bit circular and I = don't think I can add much to what I've already stated.  My research??? comes = from the actions I've assembled and various tests on models.  Many people = have wider parameters than I am suggesting and are willing to live with the changes = necessary in regulation.  Any change in the action ratio, by = definition, will cause some change in the regulation.   Action ratios of = 5.75 - 5.85, I am finding, produce the regulation specs that I outlined.  = If the action regulates at 10 mm dip and 45 mm blow at R = 5.75, then if you = change the R to 5.5 you will not be able to regulate the action with the same = dimensions unless you alter the aftertouch.  Since I aim for only enough = aftertouch to adequately clear the jack from the knuckle, any reduction creates = potential problems.  On a concert grand, where blow distances increase slightly, a higher ratio is necessary if you want to maintain 10 mm = dip and  aftertouch.  </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>I don't restrict myself to 80% of FW, that is my = target.  If a particular set of hammers cause things go over a bit or under a bit = I don't worry about it.  Thus the SW zones are not limited to mid range, = they can creep up a bit if I am willing to up the BW, FW or both, which I do on occasion.  You keep harping on this pppp ffff thing, as I mentioned = in a previous post, this is a small consideration.  The tonal = improvement reaped from moving the SW zone beyond where it can be accommodated by an R of = 5.75 - 5.85 without assist springs, overly high BW's or FW's does not produce = enough (if any) tonal improvement to warrant such a change.  That is my = opinion, of course.  Quality of tone is not yet quantifiable and so is = always a matter of opinion, which I don't mind having.  Th bottom line = in all this is that  those who are entertaining recent trends of very low = action ratios to deal with what I consider a passing fancy of high strike = weight zones would do well to consider whether the supposed benefits outweigh = the costs.  </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Nobody needs to take my word for it.  I'm just = offering this up as my experience.  Try it yourself or do what you = want.  And good luck.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>David Love</FONT></DIV> <DIV> </DIV> <DIV> </DIV> <DIV>----- Original Message ----- </DIV> <BLOCKQUOTE dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Richard.Brekne@grieg.uib.no href="mailto:Richard.Brekne@grieg.uib.no">Richard Brekne</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> October 17, 2002 12:20 = PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: To be or not to = be: a heavy hammer</DIV> <DIV><BR></DIV>David Love wrote: <BLOCKQUOTE TYPE="CITE"> <B><FONT size=-1>No, I don't think = it does.  The action regulates purely as a function of action = ratio, with some wiggle room.  The SW zone has nothing to do with it.</FONT></B><B><FONT size=-1></FONT></B> <P>In the context of our discussion it sure does. Because the action = ratio is being changed around to deal with higher SW zones. And this is = what you are on about. Your whole point seems to be that higher (defined as = anything above mid mediums)  SW zones demand lower ratios, which causes regulation problems and yeilds no tonal benifit. <B><FONT = size=-1>You can vary the aftertouch but you have more room on the deeper = side.  You need a minimum amount.  Tastes vary somewhat, but not generally = to the degree that it requires a wholesale change in the targeted ratio.</FONT></B><B><FONT size=-1></FONT></B> <P>You draw up a very narrow set of parameters indeed David. Mine = are quite a bit wider, tho as I have stated not so wide as force the use of = whippen assist springs to or go over the maximum FW standards. You state = that tastes do no vary largely enough to justify any ratio outside 5.85 - 5.75 = range. What evidence do you have that this is true ? Where is your research = that confirms this assertion ? <P><FONT size=-1>So let's do the math.  Let's take note 18 in = high strike weight zone.</FONT> <P><FONT size=-1>After re-inclusion of the qualifier to my above = statement, I find this example out of the scope which I drew up. Indeed, I = stated right out that when one reaches this highest level (and you picked the = absolute highest) one runs into problems. We could just as easily do the same = for the absolute lowest.</FONT> <B><FONT size=-1>But the issue = doesn't exist at the lowest level in the same way.  There are no concerns about exceeding front weight maximums.  Anyway, my point in this was = "why heavy hammers".  The example I gave of a high zone hammer is = something I recently saw on a Stanwood project.  (One that I was asked to = undo, BTW)</FONT></B>  <P>No it doesnt, you are correct. There are concerns however about = problems with regulating within the specs you give and still maintaining a = good balance..... or perhaps you take issue with that as well. This would = be an interesting turn worth persuing me thinks ? <P>Your point was "why heavy hammers ? ". You justify your point by <BLOCKQUOTE>1: a subjective opinion on the tone benifits of heavier hammers. <BR>2: a claim that outside the 5.85 - 5.75 ratio range = the action regulates poorly. <BR>3: an assertion that the velocity of = light hammers compensates for lower mass, even to the degree of = providing better pppp control.</BLOCKQUOTE>These are the centerpins to your = argumenation so far as I can see. So since you decided on an extreme heavy SW = example, I took the opposite extreme which as far as my understanding goes = requires a higher ratio to balance well. A higher ratio increases hammer = velocity relative to key travel, where as a lower one appropriate for heavier = hammers does the opposite.  In fact at least one major manufacturer has = moved in this direction, opting for a key deep of a bit under 10mm as part = of the configuration. Fits the bill so to speak... unless the whole bill is = wrong to begin with. <B><FONT size=-1>It's a bit jumbled.  But = in short, I think that regulation rules in terms of decision making on = actions.  The rest must fall within the area where regulation requirements can = be met.  I don't think I said anything about restricting weights = to low mediums.  I think the ideal regulation happens with an action = ratio of 5.75 - 5.85.  You can do the math from there to figure out the = highest strike weight zone that will keep you in the ballpark when you = factor in desired balance weight and front weight.  Pushing up the strike = weights to high zones for the sake of aleged tonal benefits creates other = problems that, in my opinion, are not adequately solved by the currently = employed protocols.</FONT></B> <BR>  <P>By restricting the ratio to a range of 5.75 - 5.85, limiting = yourself to maxium FW's at 80% or below of the maximums Stanwood gives, and not employing an assist spring, you infer a SW zone that does not exceed = the middle part of the mid SW zone. Which aggrees nicely with your = stated preferences for SW's. <P>Take your example note 18. Mid medium is about 10.6 grams SW. 80% = of the max FW comes out to 29.6 grams. A 5.75 ratio and 9 gram WBW yeilds a = BW of 40.35 here. Fine enough... but you cant add much SW without needing = to change things... hence the infered SW restriction to mid mediums or = below. <P>Increase this SW to just 11.7 and leave all else the same and you = have a BW of 46.7 But by accepting a 5.6 ratio and FW's at 90 % you can = achieve the same BW with this increase in SW. There is no way a 5.6 ratio is = difficult to regulate, even within the 10mm dip 45 - 48 mm blow you parameters = you give. And there is no evidence given to support the claim that this = small increase in key inertia creates a "problem". <P>I still maintain that SW zones up to the mid highs do not cause = any of the regulation problems you claim. For your note 18 that would be = 12.4 grams. A 5.6 ratio here yeilds max FWs and thats it. Same BW, same = key dip, virtually same everything else. Wheres the problem ? = <BR> <B><FONT size=-1>Pianists tastes in touch and sound do vary, but not as = largely as you think in terms of what is needed as far as design.  You can = achieve a wide enough range of touch and tone within the parameters that = I've outlined to accomodate 99% of the pianists.  Similarly with = tone.  The designs I see that incorporate high strike weight zone hammers, = I believe, have a more limited range of who they will accomodate and = so I would not advocate them as a standard approach.</FONT></B><B><FONT size=-1></FONT></B> <P>I beg to differ, but I am willing to look at any documentation or = research done that would support this claim. My own experience tells = me different, and the only large information base compiled on the = matter would also seem to point in this direction. In any case, none of this last = paragraph can serve as a basis for condemnations of configurations = which employ ratios moderatly outside the range you give. Tho I will = aggree that any  "standard" approach concept would be best to approximate = an "on average" representation of measured preferences. <B><FONT = size=-1>David Love</FONT></B></P></BLOCKQUOTE> <P><BR> Cheers David. And thanks for the interesting exchange. = This is what the list is all about eh ? <BR>  <P>Richard Brekne <BR>RPT, N.P.T.F. <BR>UiB, Bergen, Norway <BR><A href="mailto:rbrekne@broadpark.no">mailto:rbrekne@broadpark.no</A> = <BR><A = href="http://home.broadpark.no/~rbrekne/ricmain.html">http://home.broad= park.no/~rbrekne/ricmain.html</A> <BR>  </P></BLOCKQUOTE></BODY></HTML>