[CAUT] Baldwin D bridge

Edward Sambell esambell at yahoo.com
Wed Nov 17 09:46:16 MST 2010


Mick,

What you describe (so well) is the design of the original Erard action. There is 
a small drawing of it in the book on upright and grand regulating by Carl-Johan 
Forss (page 355). I tuned many of these when working in London, UK, many years 
ago. The French hung on to the basic design with later modifications. I had a 
customer here with a 1920 Erard with one version, but am surprised that yours is 
as late as 1943. Basically, I feel this to be mechanically superior to both the 
key rockers as used by older Bechsteins and to our standard capstans. There is 
little friction and the need to position the intersection of the capstan and 
wippen heel on a straight line is eliminated. Also, the key and action are 
linked, preventing any tendandtcy for  the action to bounce off the key, though 
this does not seem to be a problem in the modern action. Nonetheless, I would 
like to see if this happens on high speed video, which appears never to have 
been investigated, unless I have missed it. Most high speed video concentrates 
on the hammershank and string. Obviously, the design is impractical, and one can 
well imagine plenty of complaining in the early factories. There were other very 
good details, long since abandoned, the hammers had no tails, so were 
lighter,and they checked on a wire protruding through the repetition lever 
(balancier) in front. This permitted the keys to be removed without removing the 
stack. 

The original Erard had brass flanges with adjustable center pin bushings. This 
was achieved by slitting the flange and fitting a tightening screw, similarly to 
American square pianos. My customer's piano had conventional wood flanges. One 
idea it had was unfortunate though; the edges of the windows  in the repetition 
levers were covered with shiny white sheepskin, and the knuckles had worn them 
right through. The old Erards I tuned were straight strung with oblong tuning 
pins which I tuned with a T-hammer. Most had dampers underneath the strings, 
held up by springs. If a spring broke, you were in deep trouble. I could have a 
good deal more to say on these early instruments, but I hope you find this of 
some interest.

Ted Sambell




________________________________
From: mick johnson <mickjohnsonrpt at gmail.com>
To: caut at ptg.org
Sent: Tue, November 16, 2010 11:08:41 PM
Subject: [CAUT]  Baldwin D bridge

Alan - I service one of those with the added weirdness of not having traditional 
capstans. The backs of the keys and whippen bottoms are mortised and pinned 
together with wooden abstract. It has a double-ended capstan in the middle 
operating like a turnbuckle. The bottom of the abstract is forked and snaps onto 
the center pin on the back of the key, so anytime you remove the stack they all 
have to be pulled off and snapped back on. It was built in 1943. I haven't 
figured out if the design had something to do with the war effort or 
recreational drug use. Has anybody else seen this?


Mick Johnson, R.P.T.
University of Nebraska, Kearney
Kearney, NE
308-237-9264


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