The Tuned Bronze Casting
The bell casting is the heart of the handbell.
It is made of traditional bronze bell metal (approximately 80 percent pure
copper and 20 percent tin), the result of the molten metal being poured into
a sand mold and allowed to harden by cooling.
The rough casting is then precision turned inside and out on a lathe to an
exact profile and musical specification.
Much time, care, and skill goes into turning and tuning each bell so that
its two principal tones, the fundamental and the twelfth, will be in
exact relationship with each other, and with the other bells in the set.
The tuned bell casting is clamped between the
handguard and the
yoke-handle coupler, and is separated from
them by means of lockwashers.
On the inside lip of the bell you will find a scribed mark about 1/2" in length.
This is not a crack or defect in the bell, but has been placed there to fix
the point where the clapper should strike the bell for best response and
minimum beat or "wow".
After the bell casting has finally been tuned and the bell completely
assembled, but before the main assembly screw in the handle has been tightened
to lock the tuned casting into a fixed relationship with the handle and
clapper mechanism, the point of best response is selected.
This is done by ringing the bell while turning the casting in small incrememnts.
The trained ear of the bellcraftsman then determines the point of clearest
response and least "wow".
The main assembly screw is then tightened to lock the bell in that position.
The clapper will then strike the bell at that point and 180 degrees from it.
Although handbells will not change pitch unless there has been some change to
the bell casting by removal of metal, damage, etc., the point of best response
may change over a long period of time due to aging of the metal, damage to the
bell by nicking or chipping the lip, etc. Should you determine that a change
has taken place, you can select a new strike point by the following procedure:
- Loosen the main assembly screw in the handle just enough so that you can
turn the bell casting while holding the handbell by the handle.
- Ring the bell and listen to the tonal response for clarity and the
rate and amplitude of any beat or "wow". Damp the bell by touching the lip
with your free, gloved hand to stop the vibrations, turn the casting
approxiamtely 1/16", ring it again and listen.
Continue this procedure until you have turned the bell through at least
180 degrees, and determine if there is another point where the bell rings more
clearly and with less "wow".
- If a new and better strike point is found, tighten the main assembly
screw, then hold the clapper against the bell and scribe a new strike point
at the exact center of the face of that part of the clapper touching the
bell.
A light mark by a hard, sharp pointed tool is all that is needed.
This will not damage the bell or its tone.
Being able to "revoice" a bell and to select a new strike point without
having to return the bell to the manufacturer us another exclusive feature of
our handbells which will enable you to enjoy maximum performance from them
with minimum maintenance and expense.
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