A design that is quite easy using one type of
software can become very complex if another
one is used. For example, to design a model
with recurrent geometric patterns, like a bangle
adorned with fretwork, then a true CAD, that
is a solid modelling system, is preferable.
In contrast, if you want to design an artistically
very elaborate object, a CAID system, that is
a surface modelling system, is preferable. Consequently,
software selection should be carefully considered
and should be based on production characteristics
and potential of the company. It must be remembered
that CAD design is definitely not automatic
and always man is the “thinking”
subject. A wrong choice can cause big problems
in the use of the system and, in some cases,
can make it completely useless.There is a wide
range of modelling systems offered in the market
and an inexperienced company can have great
difficulties in making the correct choice.
After this premise, we can consider the step
that comes after CAD modelling, by CAM. CAM
is a computer directed and controlled production
activity. CAM technology not only allows direct
control of machines and of a company’s
functions, but can also enable production planning,
in order to reach the following objectives:
- automatic diagnostics of production process,
- product quality analysis,
- collection, organization and recording of
data on process stages and work
- and, principally, production control.
To gain a better understanding of the above
topics, we will examine a practical application
of CAD/CAM in jewellery manufacturing. The task
of the jewellery designer and of the goldsmith
can be divided into two phases. The first phase
concerns CAD modelling: The designer’s
idea (usually a sketch drawn on paper) is the
starting point. The next stage is the realisation
of the drawing with the CAD program.
The mathematical model is analyzed with the
same program to verify the surfaces and control
any possible errors. Finally, to get a better
understanding, the finished object is simulated.
This phase is named “rendering”
by the technicians, but is not essential for
the production of the model. It is used only
to check the aesthetic characteristics of a
jewellery piece. Now comes the second phase,
CAM manufacturing, where the machining route
Obviously, the material machined is not necessarily
gold but, more commonly, a cheap material is
used, such as wax, plastic or a base metal.
When tool type and machining technique have
been defined, simulation of machining can begin.
Now, once the machining route is ready and it
can be sent to numerically controlled machines
for the manufacture of the real object.
sum up, what does a CAD/CAM system mean today?
A CAD/CAM system is able to carry out the development,
control and preparation of the model, or of
the tools required for model manufacturing,
such as moulds or templates, setting of machine
tools. Above all, it enables a clear integration
of the above phases in an integrated 3-dimensional
in the factory :
Now the next question
to be answered is ‘how can these technologies
be introduced in the jewellery factory?’
Introduction of these new technologies in a
company, or to arrange for the company to utilize
them by means of new specialized design companies,
can give substantial advantages in terms of
cost and time required for making a model, but
it is not exempt from problems.
In particular, it has been observed that, generally,
the introduction of these new technologies can
lead to one of two opposite reactions, either
the company totally refuses to consider the
new technology or takes a liking to it and tries
to use it at all stages of the production process,
possibly fully in-house. In the
First case, the refusal generally comes from
the fear of change. At the start, some manufacturing
operations will require changes that will result
in some unavoidable opposition inside the factory
by the operators who will see it, wrongly, as
a challenge to their work or to their position.
I stress “wrongly” because these
new technologies absolutely do not aim to reduce
or limit the tasks of designers or model makers.
On the contrary, when these new systems are
integrated into the factory production process,
they will have much wider freedom of action
and a stronger stimulus to imagination.
There is also the second
case, when these techniques are not only accepted,
but even extolled, when the first results are
achieved. At this moment a new problem arises
that is exactly opposite to the first case:
The entrepreneur tries
to do every thing with the computer, even the
operations that can still be made more easily,
logically and economically by hand.