[pianotech] accelerated action

[David Love]

Gee, I better read it again to make sure it's still current.
David Love
www.davidlovepianos.com
(sent from bb)

-----Original Message-----
From: wjwallace <wjwallace at amherst.edu>
Sender: pianotech-bounces at ptg.org
Date: Tue, 18 Jan 2011 16:26:48 
To: <pianotech at ptg.org>
Reply-To: pianotech at ptg.org
Subject: Re: [pianotech] accelerated action

Thank you David. That is most helpful as is the blog on your website. 

Bill
On Jan 17, 2011, at 11:14 AM, David Love wrote:

> I don't think they changed that--I assume you mean the feet supports for the
> action rails.  The hammer flange center to string height is supposed to be
> the same as the bore distance did not change.  They just removed the shoe on
> the key and replaced it with the roller bearing in order to maintain the key
> height.  That can sometimes cause some problems with keys that are too
> flexible especially on the D (referred to as action saturation).  The
> geometry did change with the accelerated action but it's hard to know what
> was intended as they tend to be all over the place.  The early accelerated
> actions had 16mm knuckle hanging and key ratios that were quite high in the
> neighborhood of .56 or .57 (Stanwood method).  Combined with the new hammer
> they started using which was considerably heavier than the hammers from
> earlier eras these actions have a tendency to be very heavy.  
> 
> I don't see an issue with using a non accelerated action with post 1934 to
> stack rails.  Some techs have, in fact, converted the accelerated action
> back to the original shoe configuration (removing the roller bearing) in
> order to alleviate the action saturation issue and have done so without
> creating geometry problems or, I believe, having to change the stack height.
> That's not to say that the stack height is always correct.  But that can
> happen on any action.  
> 
> David Love
> www.davidlovepianos.com
> 
> 
> -----Original Message-----
> From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
> Of wjwallace
> Sent: Monday, January 17, 2011 5:29 AM
> To: pianotech at ptg.org
> Subject: [pianotech] accelerated action
> 
> Hello Technicians,
> 
> I have a Steinway D from the early 1930's. A new Kluge keyboard was recently
> installed. It is not an accelerated action, i.e. no half round. 
> 
> When Steinway came out with this accelerated action in the early thirties,
> did they change  the top stack fixed rails to match the new accelerated
> action? 
> 
> Was the geometry changed? What if any, is the downside of using a non
> accelerated action with post 1934 top stack rails? Are there other
> considerations? Whippen choices etc. Are there mixed views on this issue. 
> 
> I would be most grateful for a reply.
> 
> Bill Wallace
>