CAD/CAM/CNC Fundamentals
How CAD, CAM and CNC work together to design and make a product, and the main computer-controlled processes: laser cutting, vinyl cutting, PCB routing, 3D printing and milling.
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Designing and making by computer
Modern engineering uses computers to design a product and then to make it. Three linked stages do this: CAD is where the part is designed on screen, CAM turns that design into instructions for a machine, and CNC is the machine that carries out the work. This module looks at those stages and the main computer-controlled processes.
The three computer stages
Learn these four terms before you study the processes.
Adding vs taking away
Computer-controlled processes make a part in one of two ways.
Keep the three stages apart
A top answer never mixes up the stages: CAD is where you design the part on screen, CAM is the software step that produces the toolpath, and CNC is the machine that then cuts or prints the part. Remember too that 3D printing adds material in layers while milling and laser cutting take material away.
Match the process
- laser cutting
- vinyl cutting
- PCB routing
- milling
- cuts and engraves flat sheet with a focused beam of light
- cuts thin flexible film with a small blade for stickers and signs
- cuts the copper tracks of a printed circuit board
- removes material with a spinning cutter to shape a block
Match the stage
- CAD
- CAM
- CNC
- toolpath
- where the designer draws the part on screen
- creates the toolpath from that drawing
- the machine that carries out the cutting
- the list of moves the machine follows
Which stage makes the toolpath?
An engineer has finished the design on screen and now needs to turn it into instructions the cutting machine can follow. Which stage does this?
- CAM.
- CAD.
- CNC.
- Rapid prototyping.
Spot the subtractive processes
Select the TWO processes that make a part by cutting material away.
- Milling a block.
- Laser cutting a sheet.
- 3D printing a part.
- Designing in CAD.
Order the workflow
Put a CAD to CNC workflow in order, earliest first.
- Draw the part in CAD software
- Use CAM to create the toolpath
- Send the toolpath to the CNC machine
- The CNC machine cuts the part
Complete the facts
The stage where you draw the part on screen is _____. The software that produces the toolpath is _____. The machine that automatically carries out the cutting is _____. Building a part by adding material in layers is called 3D _____. Removing material with a spinning cutter is called _____.
Count the layers
A 3D printer builds a part in layers. The part is 30 millimetres tall and each layer is 0.5 millimetres thick. Divide 30 by 0.5 to find the number of layers. What is the answer?
Find the layer process
Tap the ONE process that builds a part by adding material in layers.
- laser cutting
- vinyl cutting
- 3D printing
- milling
Pick the right process
Read what each engineer needs and choose the best process.
- A workshop needs to cut a shape and engrave a logo into a flat sheet of acrylic
- A designer wants a solid three dimensional model of a new handle to hold and test
- A team needs sticker letters cut from a thin roll of coloured film for signs
Explain CAD, CAM and CNC
Explain how CAD, CAM and CNC work together to make a product, and give one computer-controlled process as an example.
- Describe what happens at the CAD stage
- Describe what CAM does with the design
- Explain what the CNC machine does