Engineering Design: CAD vs Manual
Before computers were invented, designs had to be drawn manually. Nowadays however, in the majority of situations, CAD packages are used over the traditional methods. This is due to the fact that technical drawings are much quicker and easier to do on a CAD program.
A technical drawing can take anything from a couple of hours to a few months to finish manually, depending on how complicated the drawing is. However, a technical drawing can be completed within a much shorter period, some maybe taking just an hour, using CAD.
Drawing in CAD is also a lot more accurate than one drawn manually. If you think how difficult it can be to get exactly 112mm on a ruler, and even more so to get 112.5mm, the probability of getting exactly the correct measurement is very low. With CAD however, you can simply type in the measurement required and will be the exact measurement, and you don’t need to spend money on technical drawing instruments It’s also easy to modify the drawing, correct mistakes, or make copies; with a manual drawing you would have to start again from scratch because rubbing lines out could still leave faint pencil marks and result in the drawing looking messy, and scanning a drawing can leave the copies with grainy, incomplete lines that would have to be drawn over again.
With CAD, drawings can be stored safely on the computer, and backed up on a pen drive or disk. Hand drawn technical drawings have to be stored in files, and cannot be backed up so if they are lost they have to be drawn again. CAD also allows the technical drawing to be imported into other software for testing properties such as the stress and strain of the product, or render the product to see what it looks like in different materials. Some CAD packages are 3-Dimensional, so the drawing can be seen at different angles. CAD drawings can be to be emailed to anybody in the world as well, without the need of paying a postage and packaging fee like with manually produced technical drawings. They are also received almost instantly by the recipient via email, whereas post can take days, even weeks, to arrive.
The greatest benefit of Computer Aided Design is that it can be downloaded to a flexible manufacturing system for production. This means less material is wasted, meaning lower scrap fees. The software automatically finds the machine code of the drawing and enters it into the machine so there is no need for an operator, hence fewer employees are needed so there are less salaries being handed out and more money stays with the company, plus the workers don’t have to be as skilled as they would be in traditional methods, so the company wouldn’t have to pay them as much.
Rapid prototyping is also a good way of using CAD for manufacture the product while reducing the time needed to complete the product. The drawing in CAD can be imported in computer software, and then the data can be used by a 3D printer such as the Z310 to produce physical models for testing and evaluations. This can give the company a better idea of the product and how well it will work.
Due to the recession, business has increased in intensity, and the level of competition is higher than ever, therefore companies need designing and manufacturing products to be quicker, easier and cheaper so that they can prevent them from being made redundant. Therefore, CAD is a much better method to use rather than traditional methods. Producing technical drawings manually takes a lot of time and effort, and requires a lot of skill from workers, whereas CAD is much quicker and easier, and if a mistake is made or modifications are to be taken out, there is no need to start again from scratch. The only problem with CAD is that the employees using it would have to be taught how to produce the drawings to British Standards (BS). However this would be easy to overcome, unlike the many problems with traditional methods.
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