Ergonomics and anthropometrics Flashcards
Legitimate sources of anthropometric data
BSI
ISO
WHO
Benefits of CAD
Design and development faster and more accurate over hand drawings
Networking enables collaboration
Files can be sent direct to CAM machine
Files can be sent to 3D printers
Disadvantages of CAD
Expensive to setup due to hardware and software costs and training
Software needs regular updating
Not always convenient for quick recording of ideas
Capabilities of CAD/CAM software
Virtual products can be created via renderings etc
Designs can be rostered as if 3D and viewed from any angle
Client and marketing feedback is possible despite not being real product
Faster development than physical model making
Editing skills accelerate development (scale, copy, edit etc)
Simulation for testing
Why virtually model over physically model
Mechanical designs can be checked for fit and clearance without having to physically be made
CAM process can be simulated to ensure error free machining
Production system planning is possible before investing in new equipment (eg layout all parts of production system to maximise efficiency)
Computer calculations ensure accuracy and repeatability removing some human error
CAD/CAM simulation features and benefits
It is essentially a run through Of a CAM process like the cutting path of a CNC laser
It highlights potential problems
Indicates how long machining will take
Any clashes with clamps or other tools will be seen but not cause damage
Facilitates nesting to limit wastage
What is FEA?
Finite element analysis
Virtual testing of components and products to identify stress or weak pointd
Benefits of FEA?
Analyses stress of elements of a design
Designers can simulate forces, vibrations or shock loads on products and components
Weak points are highlighted using a colour coded scale
Static and dynamic testing can be carried out
Money and time saved as designs can be modified and retested before being made
Disadvantages of FEA, simulation and virtual modelling
Expensive setup due to costs and training
Requires regular updating and technical support
Software compatibility may need to be addressed
How is a CNC laser cutter setup?
2D CAD files are converted into CNC program
Datam point setup
Speed and power are programmed
Colour codes used to identify cuts and engravings
Test run
Laser uses high energy laser beam to cut or vaporise material
Compressed gas blows waste material away to leave a clean edge
How is a CNC router setup?
Use high speed cutters to machine 2D CAD files in sheet materials such as MDF
3D CAD files can be sued to to machine models and other 3D forms in materials such as timber and modelling foams
How is CNC milling performed?
Milling machines operate in 3 axis
More robust than routers with slower speeds to suit metal cutting
Tools can be automatically selected to drill holes, cut slots and shape complex surfaces and edges
Tend to be fully enclosed to improve safety
Coolant improves tool life and quality finish by reducing friction
More efficient than human operators as automated
How is CNC turning performed?
Turn metals and plastics in bar form to create pre-programmed x and y axis profiles including threads and bored recesses
Automatically change tools (often made of tungsten carbide tips)
How does a CNC plotter cutter work?
Plotter cutters are used to cut shapes in compliant materials such as self-adhesive vinyl
Generate x and y cutting path from 2D CAD files
Pieces produced are often used for graphics applications
Puddle sheet material in and out of machine while cutter moves side to side.
What is a rapid prototyping process?
Use of computer operated machine to produce realistic 3D models from CAD files
