You have spent hours building a detailed CAD model. The render looks professional, the colours work and every component appears complete. But if your portfolio only shows the finished model, an examiner cannot see the thinking that produced it.
CAD evidence should capture a journey, not just a destination.
1. Follow the development pathway
Initial idea > CAD model > Problem identified > Design modified > Solution tested > Final outcome
Your portfolio should contain carefully selected evidence from this pathway. Every image needs to reveal a decision, discovery or improvement.
2. Give each piece of evidence a purpose
Different CAD images communicate different parts of your design journey.
Early CAD model: Shows how you translated an initial sketch into a three-dimensional form.
Design iterations: Reveal how research, user feedback or testing changed the design.
Assembly view: Explains how separate components connect and work together.
Exploded view: Communicates individual parts, fixings and the intended assembly sequence.
Technical drawing: Provides the dimensions and technical information required for manufacture.
Final render: Presents the intended materials, appearance, colour and finish.
You do not need to include every screenshot you produced. Choose evidence that demonstrates meaningful thinking.
3. See the difference
Weak annotation:
I made the base bigger to improve it.
Stronger annotation:
Testing showed that the 120 mm base tipped when a 600 g tablet was inserted. I increased its depth to 165 mm and moved the slot closer to the centre, improving weight distribution and stability.
The second version communicates evidence, measurement, action and justification.
4. Connect CAD to real testing
Imagine you are designing an adjustable reading stand. Your CAD model suggests that the hinge will move correctly, but a 3D printed test reveals that the parts collide at 40 degrees.
You return to CAD, reduce the hinge diameter, introduce a 2 mm clearance and print the component again.
Test result: Parts collide.
CAD response: Hinge geometry modified.
Retest: Full movement achieved.
Design decision: Revised hinge retained.
This is genuine design development because testing directly influenced the next CAD model.
5. Myth or reality?
Myth: More CAD screenshots mean more evidence.
Reality: Three carefully explained iterations can communicate more than ten unexplained images.
Software skill matters, but your portfolio should demonstrate how you used CAD to solve design problems.
6. Try the 30-second screenshot test
Point to any CAD image in your portfolio and ask:
- What does this image prove?
- What influenced this design decision?
- What changed after this stage?
If you cannot answer quickly, the image needs a clearer annotation or may not be necessary.
The strongest CAD evidence makes your thinking visible. It shows how an uncertain initial idea became a tested, technically resolved and manufacturable product.
