Autocad vs. Drafting

Modeling with CAD systems offers a number of advantages over traditional drafting methods that use rulers, squares, and compasses. For example, designs can be altered without erasing and redrawing. CAD systems also offer “zoom” features analogous to a camera lens, whereby a designer can magnify certain elements of a model to facilitate inspection. Computer models are typically three dimensional and can be rotated on any axis, much as one could rotate an actual three dimensional model in one’s hand, enabling the designer to gain a fuller sense of the object. CAD systems also lend themselves to modeling cutaway drawings, in which the internal shape of a part is revealed, and to illustrating the spatial relationships among a system of parts. To understand CAD it is also useful to understand what CAD cannot do. CAD systems have no means of comprehending real-world concepts, such as the nature of the object being designed or the function that object will serve. CAD systems function by their capacity to codify geometrical concepts.

Thus the design process using CAD involves transferring a designer’s idea into a formal geometrical model. Efforts to develop computer-based “artificial intelligence” (AI) have not yet succeeded in penetrating beyond the mechanical—represented by geometrical (rule-based) modeling. Other limitations to CAD are being addressed by research and development in the field of expert systems. This field is derived from research done in AI. One example of an expert system involves incorporating information about the nature of materials—their weight, tensile strength, flexibility, and so on—into CAD software. By including this and other information, the CAD system could then “know” what an expert engineer knows when that engineer creates a design. The system could then mimic the engineer’s thought pattern and actually “create” more of the design. Expert systems might involve the implementation of more abstract principles, such as the nature of gravity and friction, or the function and relation of commonly used parts, such as levers or nuts and bolts.

Expert systems might also come to change the way data are stored and retrieved in CAD/CAM systems, supplanting the hierarchical system with one that offers greater flexibility. Such futuristic concepts, however, are all highly dependent on our abilities to analyze human decision processes and to translate these into mechanical equivalents if possible. One of the key areas of development in CAD technologies is the simulation of performance. Among the most common types of simulation are testing for response to stress and modeling the process by which a part might be manufactured or the dynamic relationships among a system of parts. In stress tests, model surfaces are shown by a grid or mesh, that distort as the part comes under simulated physical or thermal stress. Dynamics tests function as a complement or substitute for building working prototypes. The ease with which a part’s specifications can be changed facilitates the development of optimal dynamic efficiencies, both as regards the functioning of a system of parts and the manufacture of any given part. Simulation is also used in electronic design automation, in which simulated flow of current through a circuit enables the rapid testing of various component configurations.

The processes of design and manufacture are, in some sense, conceptually separable. Yet the design process must be undertaken with an understanding of the nature of the production process. It is necessary, for example, for a designer to know the properties of the materials with which the part might be built, the various techniques by which the part might be shaped, and the scale of production that is economically viable. The conceptual overlap between design and manufacture is suggestive of the potential benefits of CAD and CAM and the reason they are generally considered together as a system. Recent technical developments have fundamentally impacted the utility of CAD/CAM systems. For example, the ever-increasing processing power of personal computers has given them viability as a vehicle for CAD/CAM application. Another important trend is toward the establishment of a single CAD-CAM standard, so that different data packages can be exchanged without manufacturing and delivery delays, unnecessary design revisions, and other problems that continue to bedevil some CAD-CAM initiatives. Finally, CAD-CAM software continues to evolve in such realms as visual representation and integration of modeling and testing applications.

-Posterity: Letters of Great Americans to Their Children…
Learn to draw. Try to make your hand so unconsciously adept that it will put down what you feel without your having to think of your hands. Then you can think of the thing before you. (Sherwood Anderson) Drawing is the ‘bones’ of art. You have to be able to walk before you can run. (Dion Archibald) Drawing is like the first kiss. It carries within it the deepest emotion and the challenge of the first step. It is the first cry after birth. (Ala Bashir) All good and genuine draftsmen draw according to the picture inscribed in their minds, and not according to nature. (Charles Baudelaire) It is through drawing that masters are first revealed, through drawing that they live and prove their value, whatever variations they may impose on their talent. (Gerard Bauer) Essay overview and thesis

It is easy to see that the use of Auto Cad has flourished in many facets of the building world. It has dominated the construction industry and is used by everyone involved in the building process from Architects to Framers. One of the reasons that the program has become so popular is due to the “import” function. This enables the user to import material of the internet and use it in their work. This function can greatly reduce the amount of time it take to produce a document, but if proper accreditation is not given for one’s work people may start to place a lesser value on intellectual property. As well, if people rely too heavily on importing other peoples work it is likely to lead to a decrease in the rate of innovation. Over the years, there has been little technological advancement in architecture and interior design methods of creating drafted plans. The most significant improvement has been the development of computer aided drafting and design, or CADD. There are many notable advantages and disadvantages when comparing the use of hand-drafting and CADD drafting for creating completed design plans. When hand-drafting, speed is a time consuming issue.

Drafting by hand requires a great deal of time, even for skilled drafters. Each line in the drawing must be extremely accurate. Creating each line with this kind of accuracy takes time because the drafter must measure each line using a drafting scale to the finest point of measurement. Any flaw in this area can be catastrophic to the completed project. Every letter and dimension placed in the plan must be legible, and appropriately placed so that every user of the document can refer to their particular section of the project. AutoCAD, a popular CADD computer software, has almost eliminated many of the problems with speed. Using a few simple mouse-clicks or commands, lines that are no longer needed can be easily erased.

Objects such as windows and doors can be copied and placed elsewhere in the drawings quickly and efficiently. Using an offset command, parallel lines used for walls and other architectural items are created automatically. There are many other commands that can greatly reduce the time it takes to draft a design plan. AutoCAD uses an automatic ruler that displays line dimensions while drawing, eliminating the need to measure and re-measure while drawing. Accuracy within a drawing is very important when creating plans. Hand-drafting leaves much room for error. If the drafter’s pencil slips by even a millimeter, the entire plan could be inaccurate. If the mistake goes unnoticed, the finished.