Action Ratio and Dip and Blow and Etc.

[Farrell]

----- Original Message ----- 
> On Jul 3, 2007, at 2:05 PM, Farrell wrote:
>> I'm working on an 1890s Knabe grand. Everything in the action is  
>> new except rails and keyframe (both of which have been rebuilt) and  
>> action brackets.
> 
> From the pix, it's clear that this is one of these 19th century  
> actions with extremely tall string heights. 

Yes it is. 8-3/4" string height.

> The line from the Rep  
> center to the cap/heel contact looks almost as steeply inclined than  
> the line from the hammer center to the knuckle/jack contact. The  
> further from horizontal is the swing of your levers, the more of the  
> the arc's motion ends up in the horizontal vector rather than the  
> vertical.

Well, the levers are horizontal, but I do agree with you that the further the contact point is between two levers (such as the wip-heel/capstan contact), the more horizontal motion will be introduced. In this case however, whereas the original configuration with some very tall back-angled capstans has tons of friction on the wip heel contact (you could easily observe the capstan sliding a millimeter or so along the heel), the modified configuration seems to be very efficient - no sliding is evident at all. So my suspicion is that this action can be setup efficiently with the current string heights - unless, of course, if there is some other major issue I am overlooking.

> It's a form of action inefficiency aggravated by tall  
> string heights. The only solution is to raise the keybed (......what  
> is this guy, nuts or sumpin'?)

Man, I'll go to some pretty far extremes for the no compromise approach, but..........

> On Jul 3, 2007, at 4:11 PM, Farrell wrote:
>> How can you be so smart to know that this action had lots of lead  
>> in the keys?  ;-)
> 
> On Jul 3, 2007, at 2:05 PM, Farrell wrote:
>> FW: 36.25 (0.966 of Stanwood's maximum FWs)
> 
> Speaking of which, you didn't list a SW. (Or was that the "F= 11.5")

Indeed, you are correct. SW on that note (#16) was 11.9 (as indicated on the hammer)
 
> Mr. Bill

Terry Farrell
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