Design Of The Cello Case example essay topic

What I will study and why I have chosen to study this product I have chosen to study the 'cello case as my family are very involved in 'cello's, my father makes carbon fibre 'cello's, my uncle owns a shop that sells different types of cases, and my sister and mother both play 'cello and have cases. The 'cello case has also evolved which makes its fulfilment of a specification greater. What I hope to learn I hope to explore and explain how and why different changes and improvements were made. I also hope to find out how the shapes in the body have been effected through time and why. I hope to find facts about the latest in the carbon fibre engineering that is being used by engineer's such as Laurence P. Green and the material properties of the fibres he is using. What I hope the reader will learn I hope the reader will learn about the changes in materials in order to suit the purpose and the overall design of the 'cello case.

I hope the reader will find my product study interesting and useful. I hope that the product study will offer a good balance between factual issues and issues to do with the design and progression of the 'cello case. What issues of design I will cover During this study I will cover the following aspects of design; -The history of the 'cello case and its evolution in design. -The change in design to suit the changes in materials or new options available with new materials.

-The user and function of the 'cello case with additional attachments involved. -Technological developments that have occurred in relation to the case's design. What issues of Manufacturing I will cover During the study I will cover the following; -The different processes used in some of the different types of 'cello cases. -Material choices, with advantages and disadvantages considered. -Tools and batch / one off production methods What methods / sources of information will be undertaken in order to obtain the relevant information. To obtain all the necessary information I will need to contact a company such as the Advanced Composites Group, I will be able to obtain information from my Father who is a carbon fibre engineer and some other information from my uncle who is a violin, viola and 'cello shop, he also constructs quality instruments.

Any additional information that may be needed (such as photo's) may be acquired from the Internet, or other information can be acquired from my Mother who is a semi professional 'cellist. My proposed Time / Action plan. Section WK 1 WK 2 WK 3 WK 4 WK 5 WK 6 WK 7 WK 8 Product Study Objectives and Content Plan of Action and Execution Analysis and Synthetics Conclusions, Evaluations, Recommendations Finishing Touches and Presentation My proposed study strategy Study Point The history of The 'cello case -Why it began-Design changes Manufacturing Processes -For GRP-For Carbon Fibre-For pre-preg fibres. Materials -GRP-Carbon Fibre (+Resin) -Carbon Fibre (Pre-preg) Why it began. The cello case was supposedly claimed to be invented by the English 'cello producing company 'Betts school', the design was developed from the large bulky containers used in the production of 'cello's.

The need was obvious because the cello's Betts school made are worth up to lb 40.000 in today's currency. Progression and history's Solid wood The original 'cello case was constructed from tough heavy Hardwood, these are referred to as 'coffin cases' as they resembled the shape of a coffin. These cases had a heavy duty framing structure and lots of inner padding, The wood did the job but often left performers with dead skin build up's, sore hands and cramp which would obviously restrict their playing. Plywood The next stage of development was around the same time Marine ply was developed; this was in the 1930's and became available due to the development of waterproof adhesives. The new waterproof ply was more flexible and could be bent around a pine frame; ply was very strong in thickness compared to solid carved wood. The Market discovered that different levels of ply could be applied and different levels of structural stability could be reached.

Cases made from Plywood are sometimes used still but they aren't nearly as popular as the FRP (Fibre Reinforced Plastic) cases. GRP As people where becoming aware of the importance of bodily strains (i.e. a growing number of bad backs from carrying their instruments) and the cost of their instruments (the cheapest full sized cello's being lb 5.000 and some were auctioned for up to lb 200.000 and the average cello being valued at 20.000-lb 30.000) as the instruments were usually over 10 years of age (cello's appreciate in value) a growing demand in light but strong cases triggered the findings of GRP (Glass Reinforced Plastic, or Fibre Glass) which was used predominantly in the marine industry. This development made the cases lighter than before with more modernised designs and the same required amount of strength. Carbon Fibre The development of Carbon fibres in the 1970's gave opportunities to new companies such as the company ACG (Advanced Composites Group) who were formed in the year 1975. Carbon fibre was a major material breakthrough, it seemed that its founders had fabricated a material as light as cardboard with ten times the strength of steel. The 'cello case industry grabbed this material when it was discovered and the first cases were produced in the early 1980's.

The original cases were so expensive only the wealthy could afford them, but it lead to the dramatic rise in sales of GRP cases as the price was lower. Now carbon fibre cases are sold for about lb 300 which is a small price to pay to protect a lb 200.000 instrument. Design changes Mostly due to the changes in materials, the designs in the cello case industry were changing. For instance when hardwood was used the extra support was a wooden frame, and with ply there was an internal frame of pine and less often, steel.

When materials such as Kevlar fibres, Carbon fibres, Carbon / Kevlar fibres, and GRP started to be used, the structure and main strength was in curves and ridges in the design. This also made the cello cases more attractive and started the main aim for cello case companies; To create a cello case with an attractive design with maximum strength offering great protection for the cello and new materials with attractive coating. At the moment there are roughly 20 different carbon fibre cello casing companies in the UK, these companies are continuously producing new designs minimising waste and excess weight for all sizes of cello case (half size, 1/4 size, 3/4 size, etc) Here are a few brands; Manufacturing processes There are several methods in which carbon fibres are used in manufacturing, I will be explaining the most common methods. Clean mould with wet and dry abrasive paper in water and detergent, making your way through levels of abrasion (coarse through to less coarse), then rinse mould.

Wax mould with a release agent to help the finished product move out of or off of the mould smoothly. With a wet lay-up, a gel coat is applied to help with the appearance and lifting out / off the mould. The gel coat not only protects the fibres but can be coloured or clear. Whether the matrix (resin) is epoxy, polyester or vynlester, care must be taken to ensure the fibre complex is thoroughly wet out to ensure that the required mechanical properties are achieved (the object is as strong as possible). It is better to have a slightly resin rich lay-up than one that is resin poor.

Voids caused by air bubbles are not desirable either, as they will weaken the structure. Polyester resin lay-ups generally are only consolidated and finished using a metal roller. Sometimes a peel ply is put down as a last layer (this will absorb resin so that a consistent amount remains through the object). Once the resin has cured, this is peeled off leaving a nice regular surface finish, which is easier to finish and paint or glue fabric onto. Carbon fibres are not normally used with polyesters not because they can't be, but because the carbon is a high performance material and the polyester is a low performance matrix.

The resulting mix will not be mechanically or cost effective. Epoxy resin lay-ups with carbon fibre will need care to ensure that the resin is evenly impregnated into the cloth. This is more difficult than with glass cloths because the visual clues to when sufficient resin is used are more difficult to see. With glass the resin and air bubbles can be seen as the glass is relatively transparent, whereas the black carbon hides these things. This is why by using a vacuum system for laying up the fibre complex, a much stronger structure can be made - free of voids (in industry void's make the product unable to be sold). Vynlester resins have qualities somewhere between the polyesters and epoxies and are easy to handle like the polyesters.

The chemical process of hardening the polyester and the vynlester resins is generally by adding a catalyst (sometimes erroneously referred to as a hardener) and typically the pot life (time available to use resin) is 15 - 20 minutes (depending on ambient temperature). This time may be manipulated by varying the amount of catalyst and accelerator. Epoxies on the other hand use a chemical reaction between a resin base and a hardener which must be mixed with accurately measured amounts with an error tolerance (less or more than set amount) of less than 5%. Pot life varies with temperature and most laminating resins will have a compatible fast, medium and slow (sometimes very slow) hardeners. Vacuum bagging requires a vacuum pump (not a vacuum cleaner) which has to be able to run for several hours at a time.

After the required lay-up, a peel ply is carefully put down on top of the wet material and smoothed out. Next is a membrane layer sometimes referred to as "bread wrap" because it is perforated and can be the same thin plastic bread is sometimes wrapped in. Next comes a bleed cloth, which allows the air to be sucked from all parts of the bag, and it also soaks up any excess resin. On top and around all this is a sealed plastic bag from which the air is sucked. A perfect vacuum will cause the weight of the atmospheric pressure to act on all parts of the mould. After the cure time (time for resin to cure or set) or longer (preferably longer) the object is carefully taken out or off of the mould and sometimes further finishing and polishing is done to perfect the product..