The Shed – September-October 2019

around a monogram that I had on a little

zinc metal stamp about the size of my

thumbnail. The two-letter options were

popularly sold at seaside fairs — mine

from Scarborough in the 1950s.

Saving work comes back

to bite me

With the radial motion of the relatively

short key, the rising tangents would have

to strike the string when the key was

almost horizontal so as not to slide off.

With the note being below the

supporting structure of the soundboard

this would mean quite a long tangent. I

cut away as much as I dared of the upper

half of the top three affected keys. All this

because of using old piano notes!

Pictures of old clavichords show the

notes angled sideways to help achieve

an appropriate length of string. This is

particularly critical in a bunden clavichord

where adjacent notes use the same string,

which dictates the distance those tangents

must be apart. I decided to use a pair of

strings for each note.

Starting from the end of the short key at

the left, I could then work out where the

tangent on each key would be under its

paired strings. This was the starting point

for the calculated length of the string from

tangent to bridge, which dictated the shape

and position of an appropriate bridge.

Using a coping saw I cut the bridge f

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alterations to the keys meant that I had
to completely rearrange their half-inch
lead balance weights and replace them
in new holes, to arrange appropriate and
matching ‘touch’ weight for each.
Fortunately, those old holes don’t show.
The back end of the key determines the
position of the tangent and the start of
the length of the string for each note.

Designing the bridge
On my roll of squared paper I made a
full-size drawing of the most appropriate
combination for string diameter and
length to work out a design for a bridge
which would be mostly near the middle
of the soundboard — which is to the
right of the notes.
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of the back of the piano keys, in
particular the available middle section
which angled to the left, a major problem
arose. With the need to obtain similar
sound characteristics throughout the
range, the appropriate gauge and tension
of wire meant that the central part of the
bridge was necessarily located rather to
the left of where I would have liked it.
This meant that the sound board
would have to overlap the upper few
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soundboard while aiming to enclose
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allow the key to operate.
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for the sound hole. In place of a classic
fretted rose, the opening was designed

Old keys remodelled. Old and new

balance pin sites. Touch weights

rearranged. Key cut down below

soundboard overhang

Drawing to calculate string length bridge shape and pin
positions. Bridge design resulting from old key shape.
Soundboard overhangs top three keys. Positioning of tuning pins

Section plan for keys and overhang