DT Topic 3

2D vs 3D models

2D - A series of flat views of an object showing it exactly as it is in shape and size i.e. constructional details; shows all details and dimensions and is usually used as a production/ working drawing; produced at the final solution stage and are used as working drawings in the realization stage3D - depicts the proposed solution in 3D showing shape and form.

Perspective Drawings

A 3D drawing that realistically represents an object by utilizing foreshortening and vanishing points (usually imaginary ones)Can be used in the planning stages to communicate what it might look like.Good for clients who may not understand orthographic or isometric drawings.

Graphical Model

A graphical model is a visualization of an idea, often created on paper or through software. Graphical models are used to communicate with oneself and others which include design team members, the client and the manufacturer. The architect would use plans (orthographic) for the builders but perspective for the client.

Rapid Prototyping

A machine that produces a complete product including internal details, at a fairly quick rate.Reduce product development time as prototypes are quickly made and can be tested; one-off products are made for different or specialised situations

Prototypes

A prototype is a sample or model built to test a concept or process; prototypes are used to test and evaluate ideas.A prototype can be a real working product made to real specifications that can be used throughout design development.It has functionality unlike that of a mock-up (minimal) or lack of it in aesthetic models.It is particularly useful in testing before production begins.Prototypes help the development team discover and issues related to manufacturing the final product.It also allows the development team to learn from the user through user feedback and user trials/interaction with the final prototype.

Surface Models

A realistic picture of the final model, offering some machining data. Surface models contain no data about the interior of the part. Surface modelling has no wall thickness.

Aesthetic Models

An appearance prototype or appearance model is as its name suggests. It is an aesthetic physical model that looks and feels like the final production product, but, does not function or operate in any way. Aesthetic/appearance models are only concerned with form, color, style, texture and how the product fits in its visual environment. They can be used for ergonomic testing, evaluating visual appeal, allow the non-designer to see and feel how the real product will be, or production engineers collect data that will help them assess the feasibility for matching manufacturing systems.

Exploded Assembly Drawings

An isometric drawing of an object with more than one component that depicts how the parts of assemblies fit together.The drawing is exploded to show component parts of a product and/or the sequence of assembly.

Part and Assembly Drawings

Assembly drawings show how different parts go together, identify those parts by number, and have a parts list, often referred to as a bill of materials.

Bottom up Modelling

Bottom up: starts with an initial sketch in which the designer builds the design.Although there are often some design criteria established before modelling the part, this information is not shared between models.Once all part models are completed, they are brought together for the first time in the assembly.

CAD(Computer Aided Design)

CAD is using computers to aid the design process, this could include creating and modifying designs (products), the analysis (FEA) or simulations.

Conceptual Model

Concept models, can be graphical, physical or virtual.The the designer visualizes concepts, design thinking and learning with:Graphical models such as flow charts, drawings and diagrams.Physical Models with clay, card, 3D printing, foam or wood (easily worked wood like Balsa).Virtual Models using CAD, simulation and other software

Digital Humans

Digital humans are computer simulations of the biomechanics of the human body.; they help to predict how a human (real) will react in a variety of situation or environments (places or locations).

Fused-Deposition Modelling

FDM machines use a heated extrusion nozzle (extruder) that moves through the x & y axisA plastic (such as ABS, PLA), metal or composite (such as30% metal, bamboo, etc ) filament is fed through the extruder; a robot that holds a small extrusion head. The extrusion head moves back and forth along a platform, building up a 3D model by feeding heated plastic wire through the extrusion head.Either the platform or extruder move through the Z axis and build the single product layer-by-layer

Finite Element Analysis

FEA ...The calculation and simulation of unknown factors in products using CAD systems. For example, simulating the stresses within a welded car part.

Instrumented Models

Instrumented physical models are equipped with the ability to take measurements to provide accurate quantitative feedback for analysis. They can be used effectively to investigate many phenomena such as fluid flows in hydraulic systems or within wind tunnels, stress within structures and user interaction with a product.For example, an instrumented model of a keyboard can record the actions of the user and provide data on how often keys are used and the number of errors a user makes (that is, the number of times the backspace or delete key is used).

Laminated Object Manufacturing

LOM machines take the sliced CAD data from the 3D model and cut out each layer from a roll of material, using a laser or plotter cutter. These sliced layers are glued together to form the modelA rapid prototyping system that creates a 3D product by converting the model into slices (2D objects), cutting the slices out and joining the slices together

Mock ups

Mock-ups are used to test ideas and gather feedback from users.They can be either full-scale or scaled models of productsThey can have some form of functionality, which means they could be considered a prototype as well.A good example of how a design begins and gets to the mock up stage. It shows gathering of information to graphical and finally physical modelling.

Selective Laser Sintering

SLS is a 3D printing process based on sintering; a high powered CO2 laser is used to sinter a thin layer of heat-fusible powder that gradually builds up the 3D model.Powders include, plastic, metal, ceramics and glass

Scale Drawings

Scale models are accurate physical representations of objects or features of objects. Scale models allow the design team, client or manufacturer visualise or manipulate (examine) the object. They are scaled down or up keeping all sizes of the features in relation to each other.

Scale Models

Scale models are accurate physical representations of objects or features of objects. Scale models allow the design team, client or manufacturer visualise or manipulate (examine) the object. They are scaled down or up keeping all sizes of the features in relation to each other.

Sketching

Sketching or freehand drawings are spontaneous representation of ideas on paper without the use of technical . Designers use a range of freehand drawings in the early stages of developing ideas to explore shape and form (3D) and constructional details (2D). Annotations explain the thinking behind the visual image represented by the drawing. They allow the designer to consider the implications of the ideas for further development. Annotated drawings are an alternative form of expression of ideas that allows one to indicate links between the ideas.

Solid Models

Solid models are clear representations of the final part.They provide a complete set of data for the product to be realized.Solid modelling techniques contain more information for the designer in order to produce a 3D model using CNC (computer numerical control) or RP (rapid prototyping) technologies

Stereolithography

Stereolithography (SLA) is a 3D printing process that uses a vat of photosensitive resin and a vertically moving platform.It uses a laser beam, directed onto the surface of the photosensitive resin, to print the pattern of the current model layer by hardening the photosensitive resin.The platform then moves down by a layer thickness so the next layer can be printed.Also known as optical fabrication, photo-solidification, solid free-form fabrication and solid imaging.Used for producing models & prototypes, casting patterns, production parts and products.

Virtual Reality

The ability to simulate a real situation on the screen and interact with it in a near-natural way.

Motion Capture

The recording of human and animal movement by any means, for example, by video, magnetic or electro-mechanical devices.

Top-Down Modelling

Top down: starts with a 3D shape in which the designer removes material to build the design. Top down modeling is a product development process obtained through 3D, parametric and associative CAD systems; done adding components or new parts to existing parts.the main feature of this new method is that the design originates as a concept and gradually evolves into a complete product consisting of components and sub-assemblies.

Physical Modelling

Used to visualize information about the context that the model represents. It is very common for physical models of large objects to be scaled down and smaller objects scaled up for ease of visualization. The primary goal of physical modeling is to test aspects of a product against user requirements. Thorough testing at the design development stage ensures that an appropriate product is developed.Used

Virtual prototypes

Virtual prototyping using CAD (such as surface and solid modeling) to develop interactive models that are photo-realistic. These are digital mock-ups.

Haptic Technology

is an emerging technology that interfaces the user via the sense of touch. Mechanical actuators apply forces to the user which gives them feedback.By simulating the physics of the user's virtual world, it is possible to compute these forces into real time.Haptic technology allows the user to become part of a computer simulation and to interact with it, enabling the designer to observe the user's performance and to design a better outcome.It can be used in different environments particularly ones that are dangerous to humans, remote locations or in difficult locations to train in.