When preparing to make an instrument, one must first of all consider one's choice of materials and create a strategy of design. The rough flitches of wood used for the front and back plates are glued together with joints that must last perhaps for hundreds of years. To shape the outline of the thin strips of maple called the ribs, a mould is made which is later removed from the structure. The front and back plates must be worked fairly thin to be able to resonate easily, but because they must also support a lot of tension, they are shaped into a very exact arching. The edges of the thin plates are then reinforced by the inlaying of the purfling which also serves the purpose of adding a visual effect. Once the outside arching of the plates has been shaped, the hollowing of the inside can begin. The graduation of the plates to the proper thickness along with the cutting of the sound holes and fitting and glueing the bassbar are really the most difficult aspects of violin making. No two pieces of wood have the same properties and must therefore be worked differently every time. The carving of a scroll on the end of the neck of as stringed instrument has a long tradition and probably has symbolic archetypal significance. After the finished instrument has been coated in a glorious veil of tinted varnish, it can be adjusted tonally by means of the sound post and other aspects of the final fitting up.
violin exploded view
Here are some very useful measurements of violin family instruments. Please let me know if you come across any mistakes or have suggestions on adding to or improving this list.
The Violin, The Viola, The Cello and The Bass
The
woods traditionally employed for the construction of the violin family instruments
are maple or sycamore
for the back, ribs and neck, and generally spruce for the belly. The variety
of maple used most generally is the Acer Pseudoplatanus and Acer Platanoides.
The maples are medium sized trees with long-stalked, palmately lobed leaves,
small regular flowers and a characteristic winged fruit called a "samara" or
key, borne in pairs. 
The spruce used most often for stringed instrument fronts is the Picea
abies or the Picea excelsa, the common christmas tree, with its whorled
branches, narrow needlelike leaves which are borne on short peg like projections
of the stem. It is sometimes said that wood suitable for violins is that which
has grown at high altitudes and has had to suffer harsh conditions such as cold
weather and poor soil. While this might seem slightly myth oriented, it is nonetheless
true that wood which has grown too quickly in lush environments and rich soil,
generally tends to be less resonant and less able to withstand the stresses
it is subjected to in the finished state. It is also a well known fact that
air dried wood, seasoned for some years, without being kiln-dryed is far better
choice. This is especially true for musical instruments which are shaped to
a thin form and must bear the considerable tensions of the taut strings. Normally
8-10 years are considered necessary to season quality tone wood. If fresh wood
is used it will invariably distort, check and split. The violin maker bites
on his wood to try to tell whether it will be strong enough. He lets it fall
and listens for its ring. He will try to go by "feel."
One of the benefits of felling a tree by yourself is the knowledge gained by going through the process of initially cutting and eventually seasoning the material. In fact violin making has fortunately conserved the idea through the centuries up until the present that thorough knowledge of the whole process from the rudimentary steps including the preparation of all materials is the key to a successful "feel" for the work as a whole. Even if you don't plan to fell trees from scratch always it is certainly a valuable experience to do it at least once or twice. Very important is to debark the wood as soon as possible to prevent insect and fungus growth between the bark and the cambrium. A treatment of the wood with borax solution is said to deter fungus which can cause staining and discoloration in the wood. I have been told that an initial storing of the trunk upright in the direction that the tree grew for some weeks is beneficial (possibly to do with settlement of sap that is still trapped in the pores. Storing the wood for the first few months is generally done outside under a simple shelter as rain or moisture is not detrimental to the wood at this stage except for the fact that a high moisture content attracts fungus growth and insects such as woodworm. Speculation as to whether the great masters of the seventeenth and eighteenth centuries treated their wood in some way will be ignored here and the accepted belief that air dried wood which is left completely intact is the best material to make healthy sound instruments of the future is correct. The traditional species used are spruce for the front (picea abies,norway spruce-known to violin makers as picea excelsa) and for the back, sides and neck, maple or sycamore-that is acer pseudoplatanus.
There are generally two ways to cut flitches from the tree trunk for violin family plates. One is radially from the core of the trunk and is usually referred to as being "on the quarter", and the other is tangentially on the perimeter and usually called "from the slab
Quarter cut and slab cut respectively 
Renaissance people believed Pythagoras' teaching that beauty was the result of perfect number ratios. The shape of the instrument is designed to withstand forces and direct them to a state of equilibrium, and the beauty of the curves is a direct and unavoidable consequence of this. The design of the classical instruments was of course influenced by renaissance thinking, where mathematics, harmony and knowledge of aesthetics was fused from a variety of disciplines including architecture, painting, astrology and music. In these times it was quite common for a chemist to delve into music, philosophy and painting, and a painter to study astrology and mathematics. There is strong evidence to support the fact that the classical violin makers employed geometric construction involving the influence of the early greek and roman theorists such as Pythagoras, Plato and Vitruvius, although there seems to have been a fairly free execution of these principles.
The glue used for all joints of the stringed instruments is traditional hide glue made from converted collagen. Although it is a very strong glue, able to hold wooden parts together with great force, the joints must be perfect. Hide glue is not an adhesive that fills gaps, so the plane iron has to be honed to a razor sharp edge and the joints planed with great precision. The main benefit of hide glue in the construction of musical instruments is its reversibility. Quite often instruments have to be repaired and restored, and hide glue will always come apart without the danger of damage if the repair is properly done. The use of synthetic glues such as PVC and the like to repair instruments has done more damage than anything else. The joints on a violin include simple butt joints such as the center joints of the plates and the complex joints of the neck. It must be considered of prime importance to the health and longevity of the instruments to have the joints in order. Hide glue is a superlative adhesive, but requires some skill to use properly. If the joint is not clamped quickly enough, the glue will begin to gel, and the bond will be unacceptable. The best way to prevent the glue from gelling, is to keep the surfaces of the work warm while working to keep it liquid for the longest possible time. Sometimes, it is possible to leave the parts to be glued, on a radiator or any other warm place, and often a hair dryer or a paint stripping gun is the best way to warm up the pieces. Various methods have been used to retard the setting time of the glue, when glueing large surfaces. Urea has been added in small quantities, and some people have added small amounts of liquid hide glue to the mix. My grandfather used beer as a retarder. Liquid hide glue is generally considered an inferior material, but can therefore be of use for some things. For example, glueing ebony nuts to the neck. Nuts need to be removed occasionally, and a strong bond can lead to damage when removing.
It is thought that the early Egyptians may have been the first to extract glue from pieces of skin with water. Traces of hide glue have been found holding ancient artifacts together. In the early days of violin making, glue making was a well founded tradition in many of the arts, although it was made by each individual craftsman rather than by specialized manufacturers. Glue,like gelatin is a product of the action of heat and water on collagen and can be extracted from skin or bones. Hide glue is superior to bone glue and is generally used for making violins.
The glue manufacturing process is basically the following:
*wash to remove dirt
* soak in lime water for 60-90 days
* wash to remove hair and lime
* neutralize with acid, drain, wash & drain
* add water, heat to 110-120 deg. F for 2-4 hours (called an extraction)
* drain off the dilute glue solution, evaporate, chill, dry, grind
* repeat last 2 steps 3-4 times to extract all of the glue with the temperature being increased 20-25 deg. F each time.
The process can lend itself to "home brewing" but it is messy and the aroma is found by some to be less than exciting! Your best bet is to buy the finished product from a reliable supplier.
CHEMICAL COMPOSITION
Hide glue is a protein derived from the simple hydrolysis of collagen which is a principal protein constituent of animal hides. Collagen, hide glue and gelatin are very closely related as to protein and chemical composition. An approximate chemical composition for glue is:
*Carbon 51-52%
* Hydrogen 6-7%
* Oxygen 24-25%
* Nitrogen 18-19%
* Total 100 %
The molecular weight of hide glue has a wide range from 20,000 - 250,000. The higher the gel strength, the higher the molecular weight.
Info courtesy of Eugene Thordahl of Bjorn Industries.
The
ribs are the 4-6 strips of maple or sycamore which make up the structure separating
the back and front of the violin. It has been said that they have a secondary vibrational function,
but contribute considerably to the transmission of vibrations between the back
and front of the instrument. Nowadays with the advent of modal analysis and a new understanding of vibrational behaviour, it is more rational to think of the sounding body as a whole and that the ribs are simply part of the body, contributing to the manner in which the instrument vibrates by their stiffness and mass. The ribs also define the volume of air inside the whole
structure, along with the interior shape of the plates. They are bent with
heat and humidity to conform to the shape of the mould. There are two principal
types of mould for the making of the ribs: 1.The interior or italian mould, and:
2. The exterior or french mould. The ribs are occasionally also built without
a mould on a flat wooden plate or on the back itself.
Making a
violin requires great patience, especially when it comes to the graduation of
the thicknesses, as each individual piece of wood has its own properties, being
a natural material. It takes a long time to shape and thin the wood, tapping
and flexing it until the maker is satisfied with the response of each piece.
When it comes to the hollowing of the plates the maker is confronted with one
of the more difficult aspects of the making of an instrument. One of the reasons
for the difficulty of mass producing violins is the fact that the wood never
has the same properties, even pieces of spruce or maple from the same tree.
When the flitches of wood are held and struck with a blow of the fist, some
pieces are found to vibrate loudly with a long ringing tone, whereas other pieces
sound dull and the note dies away quickly. Of course there are also qualitative
differences of the wood such as hard and heavy pieces which will require different
thicknesses in the end as opposed to light soft pieces.
The sound holes with
their curious shape, apparently ornamental, have a great influence on the timbre
of the instrument. Basically they communicate the volume of air inside the instrument
(which has its own modes of vibration) with the outside air which is the medium
in which the waves are carried from the instrument. The size or openness of
the holes influences to a large extent the frequency of the vibrating mass of
air within the instrument, and therefore the selective reinforcement of certain
notes. The holes also influence the flexibility of the front plate and consequently
affect its vibrational patterns. They are cut with a small fine saw and
then finished with a razor sharp fine pointed knife.
The sound post is a cylindrical piece of spruce approximately 6 mm in diameter
in the violin, which is fitted to the interior of the instrument between the
back and front. The sound post is not glued in place but is held in position
by the innate tension in the instrument caused by the pull of the strings. The
main functions of the sound post are to reinforce the belly on the treble side,
to affect the vibrational behaviour of the plates and to counteract the forces
acting on the belly from the strings. The sound post is placed inside the instrument
with a sound post setter and gradually shaped to fit the inside surfaces. The
position of the sound post can affect the 
The varnishing
of a violin has two aims basically. One is to permeate the wood with a substance
which can protect it from dirt and sweat . Another aim is to cover the instrument
with a coloured sheath of 
