2. Computer Aided Design

Feature	Adobe Illustrator	Affinity Designer
Pricing	Subscription (Adobe Creative Cloud) — school license available	Free (acquired by Canva in 2024, now free for all users)
Industry Standard	Yes — widely used in professional environments	Growing adoption, but less prevalent
Ecosystem Integration	Seamless with Photoshop, InDesign, Adobe suite	Integrates within Affinity suite only
File Format Support	AI, SVG, EPS, PDF, DXF, and more	SVG, PDF, EPS, AI (limited), Affinity native
Learning Resources	Extensive tutorials, community, and official support	Good documentation, smaller community
Performance	Resource-intensive on older hardware	Lightweight and fast
Advanced Features	Variable fonts, generative AI tools, live trace, scripting	Non-destructive editing, pixel-perfect design mode

My Choice: Adobe Illustrator

I chose Adobe Illustrator because the school provides a license at no personal cost, so it is fully accessible. It is the industry standard, with strong file-format support (especially SVG and DXF for laser cutting and fabrication), a large community, and smooth integration with the rest of the Adobe suite. Although Affinity Designer is now free after its acquisition by Canva, Illustrator’s broader ecosystem and fabrication-ready export options make it the better fit for this course.

I used Illustrator to draw the 2D vector artwork for laser cutting: flat parts that assemble into a three-dimensional Bumblebee-style model（大黄蜂的立体模型）.

I also practiced aligning and spacing multiple objects to exact distances. In the Align panel, choose Align to Key Object, select the key object, then use Distribute Spacing (horizontal or vertical) to set the gap between that object and the others.

Feature	Onshape	Fusion 360	Blender	Rhino
Pricing	Free (education/public), paid plans	Free for personal use, paid for commercial	Free and open-source	One-time license (~$995)
Platform	Browser-based (cloud), no install needed	Desktop (Windows/Mac), cloud sync	Desktop (cross-platform)	Desktop (Windows/Mac)
Modeling Type	Parametric CAD	Parametric CAD + CAM	Polygon / sculpt / procedural	NURBS surface modeling
Collaboration	Real-time multi-user collaboration	Cloud-based sharing	File-based, no native cloud collab	File-based
CAM / Fabrication	Basic export (STEP, STL, DXF)	Built-in CAM for CNC and 3D printing	STL/OBJ export, no native CAM	Export to STEP, STL; plugins for CAM
Learning Curve	Moderate — intuitive browser UI	Moderate — feature-rich interface	Steep — complex for engineering use	Steep — NURBS workflow differs from CAD
Best For	Team-based mechanical design	Integrated design-to-fabrication workflow	Visual/artistic 3D, animation, rendering	Architecture, complex surfaces, jewelry

My Choice: Onshape + Fusion 360
I selected both Onshape and Fusion 360 as my primary 3D tools. Onshape is ideal for collaborative parametric modeling with no installation required — perfect for working across devices. Fusion 360 complements it with its built-in CAM capabilities, making it well-suited for preparing models for CNC machining and 3D printing directly within the design workflow.

Tip: Using Save for Web (Legacy) gives you a side-by-side before/after preview and shows the exact file size and estimated load time — very useful for optimizing documentation images.

Tip: For screen recordings (e.g. showing software workflows), you can also lower the resolution to 720p and reduce the framerate to 24 fps — the quality difference is barely noticeable for tutorials, but the file size drops significantly.

Step 1 — New Document & Set Units to mm

Go to onshape.com and click Create → Document. Name the document (e.g. Robotic Arm). Once inside the Part Studio, open File → Units and set all units to millimeters (mm). This ensures all dimensions remain consistent throughout the model.

Step 2 — Create a Layout Sketch

Before modeling any solid geometry, create a Layout Sketch on the Top Plane. This master sketch defines all critical dimensions — joint positions, arm lengths, and rotation centers. Use construction geometry (dashed lines) for reference lines so they do not generate solid faces.

Step 3 — Light Blue Base (Revolve Feature)

Select the Front Plane and create a new sketch. Draw an L-shaped cross-section profile representing half of the base. Then apply Revolve → Full (360°) around the vertical centerline to produce a symmetrical cylindrical base.

Step 4 — Dark Gray Arm (Extrude Up to Vertex)

Sketch the pill-shaped arm link profile on a face of the base. When extruding, instead of entering a fixed distance, change the End Type to Up to Vertex and click the target vertex from the layout sketch. This ties the arm's height directly to the layout — if the layout changes, the arm updates automatically.

Draw a circle on the Front Plane and use Extrude → Remove to cut away a portion of the gray arm geometry, creating the joint opening.

Step 5 — Dark Blue Link (Multiple Components in One Part Studio)

Sketch the link profile on an existing face, then use Extrude → New to create it as a separate part. Extrude to the required thickness to produce the Dark Blue Link component.

Step 6 — White Clamp Coupling (Referencing the Layout Sketch)

Create the clamp coupling by referencing geometry from the layout sketch. Use Use (Project) to bring layout sketch lines into the current sketch as references — this ensures the coupling stays aligned with the arm even if dimensions change. Extrude the profile to the required thickness.

Step 7 — Clamp Part (Extrude Directly from a Face)

Rather than creating a sketch on a default plane, select an existing angled or offset face of the coupling as the sketch plane. Sketch the clamp jaw profile and extrude it to the required thickness. This technique avoids the need to manually offset planes and keeps all geometry anchored to the physical model.

• Click an existing part face to activate it as a sketch plane.
• Sketch the clamp jaw shape.
• Use Extrude → New to create it as a separate part.