IB Design Technology - Topic 3 Overview

IB Design Technology - Topic 3 Overview

3.1 - Conceptual Modelling

• Conceptual Model (CM) - a representation of a system, basically anything in this unit
• CMs can be physical, a sketch, or any number of other things
• Design Cycle - the process designers use in order to create a workable solution
• Service Design - the design of services such as a doctor’s or a hair appointment
• System of Design - the logical design of a product or service as a system
• Pros of conceptual modelling include: they give a big picture view, they help communicate ideas, and they can be manipulated easily.
• Cons of conceptual modelling include: high detail is expensive, they can be misinterpreted, and are usually not made of the same materials as the final product
• Types of conceptual modelling include graphical, physical, and virtual

3.2 - Graphical Modelling

• Graphical Modelling - Modelling an idea/design via non-physical means such as drawings or computer models
• Orthographic - design paper with a standard grid print
• Isometric - a type of design paper and view that shows a 3-dimensional-looking image
• 1-type Perspective - a drawing with a single vanishing point (points where the lines lead to, like a long hallway)
• 2-type Perspective - A drawing angle with 2 vanishing points
• 3-type Perspective - usually the highest number of vanishing points, a drawing with 3 vanishing points
• CAD (Computer Assisted Design) - The use of computers to assist in the modelling process
• 2-D CAD - Extension and refinement of 2-D sketches for professional use
• Fitted Assembly - a model that shows how parts of a product fit together
• Exploded Assembly - shows individual parts of a product separated from each other positioned relatively where they would be in the final product
• Scale Drawing - sketch of a design that can be physically bigger or smaller than the final product. The ratio of a scale drawing is (size of sketch):(real size)
• Concept Sketching - Simply drawing ideas, less professional/formal than other methods, thinking with a pen
• Formal Sketching - More organized used in the development phase
• Pros of graphical modelling include: it shows how a product is assembled and how it works
• Cons of graphical modelling include: it can be hard to produce as it requires a lot of skill, time, and potentially money (e.g. expensive software, pay designers)

3.3 - Physical Modelling

• Scale Model - A physical model of a product that has the same details but different dimensions, the ratio is (model):(product)

• Pros: Portable and cheaper to make than the actual product
• Cons: they can lose detail, especially with scaling down

• Aesthetic Model -  A model made to look like the real product, but does not function
• Mock-Up: Almost the final product, full model, used for demo, evaluation, and promo

• Can be used to test ideas for feedback
• Can be a prototype with most functionality
• Defines the proportions of a final product

• Fidelity Range - Measures how “loyal” or close a physical model is to the final product

• Lowest fidelity to highest fidelity: 

• Analagous - Can give a general idea
• Near/Total Mock-Up - Basically the final product

• Fidelities are tested in different contexts to try out ideas

• Restricted - Lab settings, many controlled variables
• General - Less restrictions, usually something similar to a focus group
• Partial - Testing with the final consumer OR in the final environment
• Total - Testing with the final consumer AND in the final environment

• Prototype - Model built to test a concept as an object to be replaced/learned form, used by both the user and dev team

3.4 - CAD

• Surface Model - Photorealistic image of a product, only shows the exterior
• Solid Model - Clear representation of the final product, with internal dimensions

• Combined the base solid and features

• Data Model - Used to determine the structure of data while testing (e.g. statistical analysis of GPS or 3D scan)
• Visual Prototyping - Uses surface and solid models to develop interactive models
• BottomUp Design - Parts are made independent of each other and with constraints, the designer brings them together at the end of the process
• TopDown Design - Starts with a rough idea of a product and makes parts that meet the criteria
• Human Digital Systems - Simulations of the human body interacting with prototypes of products, checks for safety and ease of use

• Motion Capture - Records motion, someone can wear markers captured by a camera. Reduces the cost of animation and allows for more natural movements
• Haptic Touch - Interactions through the sense of touch (like a phone vibrating)
• Virtual Reality - This allows for the simulation of various situations to interact with
• Animation - Links scenes of an environment simulated in software to observe seevral scenarios

3.5 - Rapid Prototyping

• Rapid Prototyping often uses 3D printing via CAD files, this method of making prototypes is much cheaper and quicker than machining them out of other materials
• Laminated Object Manufacturing - Cuts out slices of a CAD file from a roll of material, the slices are glued together to make a prototype
• Stereolithography - Uses photo-solidification to cure a resin in layers and form a product, one of the most detailed methods of rapid prototyping
• Fixed Deposition Modelling - Uses an extruder to lay down layers of filament one at a time (the more traditional 3d printers you see that use a plastic filament)
• Structure Layer Stitching - Uses a high-power laser to fuse small particles into the desired shape, materials usually come in a powder