Moving Action Lines of Center

[Erwinspiano@aol.com]

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In a message dated 1/18/2003 7:09:18 AM Pacific Standard Time, 
mfarrel2@tampabay.rr.com writes:

> Subj: Moving Action Lines of Center 
>  Date: 1/18/2003 7:09:18 AM Pacific Standard Time
>  From: <A HREF="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A>
>  Reply-to: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
>  To: <A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
>  Sent from the Internet 
> 
> 
>     Terry 

        In my limited experience of checking the "Magic line" at the knuckle 
I've noticed that even on the best of actions the only time the knuckle gets 
close to the line is at the very end of the key /action stoke.  (I think Ron 
Overs action is the exception.) So maybe the parameter is , that the closer 
the knucle is to the line the better. I  think the most advantage gained is 
at the wippen heel/capstan contact point. When this convergence line is right 
the action gets very  fluid. Or , as My colleague Bob Davis so succinctly put 
it to me the other night is , that leverage is leverage.
   Meaning that primarily you can move two things to increase action 
efficiency , reduce lead and increase hammer weight.  These two are the key 
balance point relative to the capstan or the knuckle placement relative to 
the centerpin.  Other than that the lines of convergence are where friction 
can seriously be tamed , there by reducing the  need to add lead to overcome 
it. Of course for me all this moving balance points and convergence lines 
around still has to land me within  .390 ish dip and a 1 3/4" to 1 7/8" blow 
distance with a 1.5mm let-off.
   Somebody else jump in here and tell me something I might be missing.
      Dale Erwin
    
> 
> I'm having a difficult time imagining how to change the position of the 
> knuckle/rep lever contact relative to the magic line.
> 
> I can see quite easily how to manipulate the wippen heel/capstan contact - 
> taller or shorter heel, capstan up and down, and/or move capstan forward or 
> back. Lots of easy opportunity to put that contact anywhere you want it.
> 
> I have a 1947 Baldwin action where the magic line passes through the 
> knuckle just above its center with the key at rest. At full key depression 
> the rep lever is almost up to the magic line.
> 
> A tiny knuckle would do it, but I have never seen one so small. I suppose 
> you could move the wippen flange down (move rail?) somehow. But that's 
> pretty weird.
> 
> Is there some easy thing I am overlooking?
> 
> Terry Farrell
>  


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