By setting all the key ratios at .53 do you actually get uniform SWR in such a case, or does the difference between the contact points on the wippen heal with varied capstan lines throw that off a bit. If you are trying to get uniform SWR, wouldn't the key ratio between sharps and naturals have to be slightly different? David Love ----- Original Message ----- From: "David Stanwood" <dstanwood@hotmail.com> To: <pianotech@ptg.org> Sent: November 08, 2001 2:15 PM Subject: Re: YC Strike Weights etc > It just so happens that we are working on a Mason & Hamlin A right now and > the Balance Rail pins between the sharps and the naturals are very close > together. A survey of 18 notes across the keyboard reveals an average > strike weight ratio of 5.7 in the naturals and 6.2 in the sharps. We are > setting a new ratio of 5.3 throughout because we want to throw 1/2 High zone > weight hammers. We are laying out two separate capstan/heel lines to > acheive this. It's the overall ratio that counts so if the sharps are > different you can certainly correct them with a separate line and get > uniform ratio and therefore similar dynamic touch between sharps and > naturals.... Using Strike Weight Ratio to determine the correct position is > a convenient method. Changing the capstan position on the sharps simply > compensates for the higher key ratio on the sharps. We've done this many > times over the years with excellent results... > > David Stanwood > > > >From: Richard Brekne <Richard.Brekne@grieg.uib.no> > >Subject: Re: YC Strike Weights etc > >Date: Mon, 05 Nov 2001 22:22:56 +0100 > > > >Isaac OLEG SIMANOT wrote: > > > > > > Just a question, > > > > > > If you relocate the capstan on the blacks only, you will have the > >contact > > > point on the whippen heel changed, so what you gain one way you loose a > >tad > > > the other. What happen to hammer and key travel now ? > > > > > > I just cant understand how you can expect to have an even touch with t he > > > capstan differently on white and blacks. The hammer acceleration will be > > > different from key to key, is not it ? > > > > > > Regards. > > > > > > Isaac OLEG > > > > > > >The actuall problem is that the leverage is already > >different on the white and black keys. Probably due to a > >frig up in figureing placement of the Balance rail pins. So > >I already have some of these problems. I am not convinced > >that moving to a staggered capstan position is the right > >thing to do. But it is an interesting idea to check out. It > >doesnt hurt to look closer at the option thats for sure. > >Certainly one objective should be to get as uniform a > >whippen travel as is possible for the same amount of key > >travel. > > > >But you mention hammer acceleration... and in all this about > >Stanwood I cant remember seeing anything about that ever > >mentioned... and I would suppose its an important enough > >issue. Anyone got any good words of wisdom on this tangent ? > > > > > > > > > >-- > >Richard Brekne > >RPT, N.P.T.F. > >Bergen, Norway > >mailto:rbrekne@broadpark.no > > > _________________________________________________________________ > Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp >
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