1.21 Digital Design and Manufacture Flashcards
Define computer aided design (CAD)
Using computers to design and develop products
Define computer aided manufacture (CAM)
Using computer-controlled equipment to machine materials
Define computer numerically controlled (CNC)
A program, converted from CAD files, which uses special codes to control CAM equipment
Name two CAM equipment
1) CNC laser cutter
2) CNC router
3) CNC miller
4) CNC lathes
5) CNC plotter cutter
CNC laser cutters
1) Covert 2D CAD designs to CNC code to move a machine head along the X and Y axes
2) Laser beam can cut or engrave materials
3) High-precision and self-finishing process
4) Requires extraction; some materials produce toxic fumes
CNC router
1) Operate on X, Y, A and Z aces to create more complex shapes
2) The workpiece is fixed to the bed of the machine
3) Requires extractiob
CNC miller
1) Moves the workpiece in the X, Y and Z axes
2) More robust than routers with slower speeds to suit metal cutting
3) Cooling lubricants can be used when cutting metal to prolong the life of the tools and give a superior finish
CNC lathes
1) Involves of a spinning workpiece, not spinning the cutting tool
2) Complete operations such as cutting, boring, knurling and thread cutting
CNC plotter cutter
1) Read 2D CAD files and cut materials such as vinyl, paper and lightweight card
2) Operate on X and Y axes
Simulation
A computer ‘run-through’ of a CAM process, which can be viewed by the designer, who also receives appropriate reports on its success
Examples:
Cutting path of a CNC lsaer
A series of turning tools creating a profile for a part being made on a CNC lathe
Advantages of simulations
1) Highlights potential problems and shows if the production will be as expected
2) Indicates how long the item will take to be machined
3) Clashes with clamps and vies or the tool moving beyond X, Y, and Z limits will show up
4) Facilities ‘nesting’ of multiple parts to reduce wastage of sheet material
5) 3D printing models’ appearance and support material requirements can be assessed
Virtual Modelling
1) The use of 3D CAD files to simulate aspects of the performance of products before they are manufactured
2) Virtual models of mechanical designs such as car engines can be checked for fit and clearance
3) CAM process can be simulated to ensure error-free machining
Computational fluid dynamics (CFD)
Virtual testing of products in liquid or gases, using CAD-based software
Finite elements analysis (FEA)
Virtual testing of components and products to identify stress or weak points
Rapid prototyping
A CAM method that produces physical prototypes from the CAD files
1) A length but a fully automated process
2) 3D shapes are built up from 2D layers
3) Sintering uses a laser to fuse layers in a bath of powder
4) Stereolithography uses a laser to cure a bath of resin, solidifying it layer by layer
