[pianotech] New custom agraffe design

[Overs Pianos]

Hi all,

I mentioned in a recent post that we were planning to manufacture 
special agraffes for our pianos, since I have finally had enough of 
brass agraffes which sometimes are capable of producing noise 
aplenty, at times even before an instrument leaves the workshop.

It took a while to get a result, but below is an image-link which 
shows a sample of the first batch of our special agraffes made from 
SAE 4140 alloy steel (this stuff is typically used for making truck 
drive axles). This sample has been hand polished and cleaned ready 
for Electroless Nickel (EN) plating. The plating is necessary for two 
reasons;

1) To provide corrosion resistance

2) To provide a suitable low friction bearing surface, since steel on 
steel is not good for friction.

The image of the agraffe can be found at;
http://www.overspianos.com.au/ove.agraffe.jpg

These agraffes feature an internal-hole profile which looks something 
like the hole of a doughnut, as a string termination shape. Provided 
that the string approach angle doesn't exceed 10 degrees, the string 
will always have clearance with the agraffe body, and will only 
contact the agraffe at the 'internal doughnut'. I'm really looking 
forward to hearing the first of these in a month or so.

The first batch will be fitted to a model D rebuild we're finishing 
off for Sydney Conservatorium of Music, and another 210 cm grand 
piano we're rebuilding, with extensive modifications, for sale.

I'm really looking forward to getting the 210 finished, since it will 
be fitted with the custom agraffes, a new capo and counterbearing 
system, comprising of a new V bar capo, and a V bar counterbearing 
bar 25-30 mm behind the capo (both V bars are hardened and EN 
plated). Also included is a 6-note tenor bridge (all bichords) with 
the agraffes relocated to preserve the hammer strike ratio, a new 
bass scale design, an action ratio revision and the inclusion of a 
set bolt at the bass-side-X, since it was left out of the original 
instrument - likely as a cost cutting measure. Overall, there won't 
be much of the original Young-Chang Steinway model B clone left in 
the piano. It will pretty much be our tonal character inside a 210 
case (hence the name change to Overs-Beale). We're planning to sell 
it for around A$60K (FOB). A description of this piano, written 
before the rebuild commenced, can be found at;
http://www.overspianos.com.au/BG7.htm

A screen-shot which shows %-break scaling charts for a Steinway B, 
the original clone and our re-design can be found at;
http://www.overspianos.com.au/7ftgrd.tens.snpsht.jpg

An image in the bottom RH corner of the screen-shot shows overhead 
images of a Steinway B and the original Beale BG7 piano before the 
rebuild started. The similarity in the scale is obvious. The Beale 
case is wider at the back, which is no advantage, despite the fact 
that the current crop of designers can't resist widening the back. 
Generally the change only results in the differing distances of the 
bridges from rim to be even worse than previously.

I'll be adding in-progress images of the new rebuild to the website 
soon, in our 'pianos for sale' section.

Ron O.

-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
_______________________

Web http://overspianos.com.au
mailto:ron at overspianos.com.au
_______________________

A web page with images of recent work and almost-audio-CD quality mp3 
sound files of the Overs piano can be found at;
http://overspianos.com.au/more_info.htm

So put on your headphones, plug them into your freshly restarted 
computer and sit back to over 20 minutes of pure piano.
  _______________________
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