Following the extremely
kind gesture by Salzgitter Magnesium-Technologie GmbH, in Germany to provide
sufficient magnesium sheet for two prototypes, one of which will be returned
to them for their own testing, I have completed construction of the first
one.
Both prototypes will be based on the same specifications, (where possible)
as my 4/4 aluminium bodied violin, for a direct comparison of total weight
and sound quality.
The overall measurements are from 'Juliet
Barker', the contour templates are for a Sacconi Strad 1716 & the
neck/scroll dimensions are from 'Strobel'.
The completed specifications of the first one are:
Body length 355mm
Top/end of fingerboard to belly 21mm
Top bout 168mm
Bridge centre height 35mm
Middle bout 112mm
E string height above fingerboard 3mm
Bottom bout 208mm
G string height above fingerboard 5.5mm
Rib height 35-33mm
Fingerboard to bridge
54mm
Body stop 195mm Tailpiece saddle to bridge
44mm
Neck stop 130mm Saddle height above belly
4mm
Fingerboard length 270mm
Vibrating string length 325mm (standard 2:3 ratio
Total length from top of scroll to endpin, approx. 600mm
Due to the difficulty of cold forming the magnesium sheet a small
reduction in the arching's has been necessary, with a corresponding increase
in rib height to 35mm, tapering to 33mm on the top bout, to maintain the
correct internal air volume.
The arching now are: top plate 12.5mm, back plate 11.5mm.
(Actual concavity: top plate 11.5mm, back plate 10.5mm.)
with
1mm magnesium used for the plates and ribs.
As the magnesium can't be bent to sharp 90 degree angles without breaking
0.9mm aluminium was used for the bass bar and joining clips.
The neck is made from Sycamore, blocks from
Spruce, sound post are made from fine grained Spruce, with ebony finger board, nut, end pins,
pegs and tailpieces with aluminium saddle.
The finished weight with chinrest attached is 614grams, 136grams lighter
than the aluminium one.
(the weight of a normal 4/4 sized
wooden violin is approx. 450grams.
The strings are:
E - D'Addaro Prelude J811 E-Mi 4/4 Polished Steel, Medium Tension.
A - D'Addaro Prelude J812 A-la 4/4 Aluminium Wound. Medium Tension
D - D'Addaro Prelude J813 D-Re 4/4 Nickel Wound, Medium Tension
G - D'Addaro Prelude J814 G-Sol 4/4 Nickel Wound, Medium Tension
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