Computer Aided Design 3D CAD Modelling

What is C.A.D? C.A.D stands for Computer Aided Design. C.A.D uses computer technology to enable designers, engineers and graphic artists to model ideas in 2D and 3D. C.A.D has many advantages and disadvantages over the traditional drawing board method.

Where do we start?

Sketched Ideas The start point for any C.A.D work is a sketch! Sketched ideas are the basis of designing products, buildings and graphics. The more detail there is in the initial sketches, the easier it is for a C.A.D engineer to create a 3D model. Freehand drawings can even be scanned into the computer and the sketch used to generate a 3D model.

C.A.D Modelling Once finalised, ideas can then be 3D modelled. Accuracy is the key to success! 3D CAD modelling is a time-saving process. The 3D model can be used for several functions once it’s made. Files should be saved regularly with sensible file names in a directory and should always be backed up using cloud storage, USB memory or external HDD. Let’s look at the uses for 3D CAD in industry

Production Drawings Most 3D C.A.D software can create production drawings of the 3D model. This allows the designer or engineer to produce orthographic, pictorial, sectional, detailed and exploded views. It is a time-saving feature, removing the need to produce the engineering drawings on traditional drawing boards or 2D C.A.D software.

Simulation Simulation allows testing of products, training of people or predicting real-world events. 3D simulations have preloaded physical data about materials, temperature and environments. Simulation using CAD reduces the cost of producing products and is a safer method for training staff.

3D Illustration Illustration (or visualisation) software improves the visual impact of a 3D model. Some illustration software allows the user to animate the model. Most CAD software has the ability to illustrate but some need additional applications to do the job.

Computer Aided Manufacture Computer-aided manufacture (CAM) allows 2D or 3D graphics to control computer-numerically controlled machines (CNC) to produce physical objects. Some 3D CAD software simulates (tests) the manufacture process prior to machining. What do you think the social implications of CAM are?

3D Prototype Printing Rapid Prototyping is the printing of 3D models. These models are exported as standard tessellation language (STL) files and imported in to 3D model machines. The model is then digitally ‘sliced’ in to thin horizontal layers. These layers can be printed. 3D printed prototypes help the designer to evaluate aesthetics and function. What do the terms Aesthetics and Function mean?

Traditional method V C.A.D Now that you have seen some of the uses for C.A.D, can you think of the advantages and disadvantages between the traditional drawing board compared to modern day C.A.D? What do you think the advantages and disadvantages of C.A.D are? What do you think the advantages and disadvantages of the traditional drawing method are?

Did you get them all? Less storage space Easier to adjust drawings Send drawings around the world Multiple copies of drawings Better quality and accuracy C.A.D libraries are available saving time Computers can crash/become corrupt Training of staff can take time Software updates can be expensive Hardware updates can be expensive Social implications – jobs are lost through the introduction of C.A.D More storage space is required Drawings are harder to adjust Drawings need photocopied for extra copies Drawings can fade and be damaged Manual drawings rely on scanners or post! Equipment is less expensive Skills are easier and quicker to learn Less training reducing costs Traditional Drawing Board Computer – Aided Drawing

Modelling Concepts 3D CAD modelling introduces us to a range of CAD commands. A CAD command is a function or process carried out as part of creating a 3D object. The following video clip introduces us to some CAD commands, these will be focused on in more detail throughout the tutorials.