The Rapid prototyping technique has been developed mainly to cater to the requirements of the manufacturing industry. However, recently RP techniques have been put to good use in many sectors apart from the manufacturing. These application sectors have a different set of requirements from what is being needed for the manufacturing. This report mainly describes how the RP techniques have been used in the area of arts and architecture. This work also attempts to bring out the main challenges when the technique is applied in this sector. We have also enclosed our views on how the technology can be improved further so that it can be efficiently used by the architects to build better buildings and structures.
The computer modeling has been extensively used to generate virtual design models. However the trend recently is to have also a physical prototype of what the end product will be like in order to have a better understanding on the features and functionality of the product developed. When it comes to the architectural modeling, the sculptors normally employ traditional methods. As we can see that use of these traditional techniques take up much time and effort although, the time can be reduced if the model maker is really very skilled. The model making process can be automated if we can use the computer aided design at the concept stage. These computer models have to be interpreted by the machines that go on to produce them which are quite a difficult process. It is where in this realm, the Rapid Prototyping (RP) can be used where CAD files are translated directly into physical models without much of difficulty. The requirements for model fabrication in the manufacturing industry are generally different from those of architecture and RP techniques have so far been successfully employed.
In this report the architectural design models have first been analyzed whereby emphasizing the fact that RP is in general demand in this sector. We have also included a brief description of the RP methods and techniques thus explaining which specific characteristics of RP can be used in relation to arts and architecture. We have concluded the report by describing different techniques illustrated by means of examples and cases to explain the considerations and problems faced in the fabrication of models in the architectural engineering sector.
Most of the design in the field of architecture has been taken care of by means of drawing the structures. The usage of prototype models as a design tool in the field of architecture has been limited till now. Most of the works reported so far has explored only a little on the demands of architectural design on rapid prototyping. Therefore an effective origin when discussing the role of RP in architecture is to examine the role of models in the design of architectures. The review that is presented in this report serves to provide a survey of the recent trend.
The contribution of models in design
The architectural design makes use of models in the design cycle . In the early stage, the models are designed rapidly and crude assemblies are made whereas in the final stages, detailed models are carefully made to better understand the final product, thus making it clear that the physical models convey a better meaning when compared to the drawn structural models . The design aspects are revealed to both the technical personnel and layman alike when prototypes are used. Scaled models are used to better explain the town planning and building structures and prove that they are an effective communication tool.
Apart from representing the form, the models can also depict the functionality so that it can be used to test the feasible construction and to integrate the individual components to complex systems. Likewise, they can also be dismantled to reveal the components or spaces in the building. The prototypes also helps one to perceive what is actually viewed rather than a concept imagined and provide a means to better explain the complex geometries.
The prototypes used for architecture have evolved over time with the developments in the field of architecture. These prototypes can be tested in the laboratory to understand the failure behavior of the actual structures, the fact being that it is more cost-effective to test these models. Prototypes could also be constructed to depict the real structures that would be quite tedious to construct using the existing construction technologies.
The major limitation of using the prototypes in architecture is that they represent merely how the final building or a sculpture will look like and as such some of the functionalities and finishes that represent in the final form will be omitted in the model. The accuracy of the finish and the level of articulation are heavily dependent on the skill of the technician and the time available. Hence, it is incumbent on the design team to take into consideration those details that are omitted or not taken care of in the prototype as they would be eventually made use in the decision making process.
For those models that will be subjected to testing, the model maker must take into account those features which are need to be tested in the prototype to have a better understanding on the characteristic properties of the finished product . Some of the prototypes that actually pass in the lab test may fail in the real circumstances due to the fact that these models much smaller when compared to the real components.
Models are an abstraction in representation. As such, the choice of materials is important, for these will influence the interpretation of the viewer. One of the more important constraints of model making is therefore the difficulty in achieving forms, texture, color or schedule with the materials and model making techniques chosen.
Some model makers or designers use real materials in their models, insisting that the model is the real object. There are obvious problems of literally translating materials from a full-scale object to one at a reduced scale. The choice of materials will often depend upon workability, ability to work at the appropriate size, representational properties or experimental behavior as well as safety in working. Longevity of the model is also an issue - a model intended for international exhibition and archiving will be made of a different palette than one intended to quickly explore a possible form.
More often, substitutions of materials are made to achieve representational likeness. As has been identified above, we can distinguish three types of model: preliminary, experimental and final. Preliminary are sketch models made quickly to approximate the shape or volume. Such preliminary models may be made from any materials at hand. Preliminary models may be refined into preliminary scale models, which exhibit greater control over the dimensions. Experimental models are made to approximate particular properties of the intended design, the particular property selected depending upon the aspect of the design to be tested or experimented.
Numerous texts present model-making techniques (Hohauser, 1984; Pommer, 1981; Michaels et al., 1993; Koepke, 1990). In these, discussions can be found of the wide variety of tools and techniques to manipulate materials to aid in representing design ideas. Here we find instructions on sheet materials that can be cut, bent, etched, formed or milled. Detailed elements can be made using rubber (latex, synthetic, or silicon) or plaster casts for cold moulding or using more traditional metal casting techniques. It is noted that finishes are often applied, taking up to one third of the time required to assemble the model (Hohauser, 1984). From this we note that a well-established body of knowledge exists for achieving representational success. All of these note, however, that model making is a time consuming and demanding process, which makes it difficult to use as a design aid. The designer often cannot afford the time nor have the skill to make any but the simplest preliminary models (Janke, 1968). The compromises made in sketch design models are such that they are of limited use. It is here that RP promises to be of great benefit in design.