CAD or computer aided design has revolutionised the way companies design products; cad is a significant improvement to using drawing boards as saves time and money in the design of new products Cad facilitates designs to be produced at a faster rate due to such tools like copy, mirror, rotate, snapping tools, smart dimensions and less repetition of parts this reduces the design time because data can be added to the drawing very quickly in comparison to having to hand draw every dimension or part.
Complex geometry is easy to add or create by the innovative tools like: splines, coincident lines, tangent arks, shelling and extruded cut these tools enable the designer to produce a complex and detailed product with all geometry accurate. The drawings made in CAD are very accurate because lines can be offset and drawn to a very accurate level (1/100mm). Data can also be accurate as lines can automatically be snapped onto centre points or an excess line can be trimmed off once the geometry has been designed therefore tidying up the drawing.
Dimensioning is vital for designers as it gives the proportion for the model which on cad can be drawn to real size without using scales to shrink the design for paper which can cause problems later. Dimensions can be added in an instant with two clicks. Many modern cad packages automatically dimension drawings to certain international standards like ISO 8888 or ISO128. ISO stands for the international organisation for standardisation.
Existing designs can be easily edited or modified to insert new dimensions or parts, copies of designs can be individually edited to produce two different versions of the product from the same parent design. Geometry can be changed very easily if a part isn’t functioning correctly. Failure can be predicted by running tests such as; aerodynamics, strength, motion and interference on the product in cad even before prototypes are made, if any mistakes or errors are found the appropriate modifications can be made to the design.
This saves valuable time and money as fewer prototypes need to be produced which decreases the time between CAD to counter. Cad can be a very useful tool for making high quality orthographic projections for the manufacturing industry so all sides and angles of the product can be seen & clean and simple dimensions can be added without making the drawing appear cluttered. This can give a high quality feel to designs and writing, logos and borders can make drawings look very professional.
Vast libraries of parts can be found in online databases or in company’s archives. These can be used within assemblies for example all standard nuts, bolts, screws, washers, fittings, bearings, mechanisms and gears have all been previously designed which can be utilized to speed up the design process as the designer doesn’t need to re-draw the part. One of the biggest libraries of parts is www. tracepartsonline.
net which allows anyone to make a free account and begin using their parts, this feature is also good for the owners’ of these part libraries as if the designed part is used in manufacturing, the company producing the product may purchase the rights to the design or buy the parts when the product is manufactured. 3D virtual modelling is the most commonly used CAD system as it allows the designer to view the product in a myriad of different positions and angles which can allow any potential aesthetic or structural faults to be recognised, changed or improved.
This makes for a more fluent design process as an exact digital replica of the product is on the screen which can show proportion and scale. Parts or assemblies can be textured to look like the material of the designer’s choice and orthographic drawings can be created in a matter of seconds from a assembly by selecting drawing from part/assembly this is very fast but would have taken much longer to hand draw. Cad models can be stored safely in many ways for example on USB sticks, CD’s or hard drives.
This is very useful as data can be stored on many different media types so the possibility of losing the data is highly unlikely when compared to how easy it would be to lose one hand drawing hard copy, this makes cad drawings seem substantially better protected. Large companies such as Procter and Gamble have their own database systems to facilitate the sharing and location of files efficiently for anyone in the company so any file submitted to the database can be easily sourced which cuts out the need for couriers to move drawings around to different parts of the company.
Designs on cad can be sent around the globe via email to places like china where the majority of product manufacturing takes place this is a significant leap in globalisation as designs can be sent and received instantly which reduces costs of mailing as well as time waiting for the drawings to travel there by boat or plane. The variety of formats that CAD designs can be saved in makes exportation into different software packages very easy for example for rapid prototyping machines, documents can be saved as STl files which are readable by the machines inquestion.