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Week 02 — Computer-Aided Design

Focus this week

I have some experience in Fusion 360, but this week I want to: - learn Joints and Motion tools (to test ideas for my final project).

Tools I used

  • Fusion 360 (joints, motion, assembly tests)
  • OpenSCAD (parametric / code-based modeling)

Part A — Fusion 360 (Linear Actuator, Joints & Motion)

Goal

For my final project I plan to use linear actuators, so this week I focused on: - building a simple linear actuator model - understanding how linear motion is defined in Fusion 360 - testing motion limits and constraints

Initial actuator test (components vs bodies)

First, I built a simple two-part model that connects and moves relative to each other.

Instead of modeling everything as bodies, I created separate components.
Using components is necessary because joints only work between components, not bodies.

Create components

Simple component connection test

After that, I built two simple components designed to join and interact with each other.

2 simple part

Next, I used the Joint function in Fusion 360 to connect the components.
I selected the two components and defined a linear (slider) joint between them.

This joint allows the components to move only along a single axis, which simulates linear motion similar to a real linear actuator.

Part B — OpenSCAD (Parametric CAD Using Code)

Goal

After working with Fusion 360 and motion tools, I wanted to try a different CAD approach.
For this purpose, I used OpenSCAD, which is a script-based parametric modeling tool.

The goal was to:

  • Understand code-based modeling
  • Compare it with traditional sketch-based CAD
  • Create a simple parametric mechanical part
  • Export fabrication-ready files

Why OpenSCAD?

Unlike Fusion 360, OpenSCAD does not use sketches or graphical constraints.
Instead, geometry is defined using code and variables.

This makes it: - Fully parametric - Very precise - Easy to modify dimensions globally

However, it does not support: - Assemblies - Motion simulation - Joints

First Parametric Test

To understand the workflow, I created a simple parametric mechanical part.

Example structure:

length = 60;
width = 20;
height = 10;

cube([length, width, height]);

By changing the values of length, width, or height, the model updates instantly.

Adding Features

Next, I modified the model to include a hole:

Simple Disc Geometry in OpenSCAD

I created a simple parametric disc using OpenSCAD.
The model consists of:

  • One main cylindrical body (the disc)
  • One center hole
  • Multiple bolt holes distributed evenly on a circular pattern

Exporting Files

After finishing the model, I exported it as:

  • STL

Then I verified the STL in a slicer to confirm:

  • Correct scale (mm)
  • No geometry errors
  • Clean mesh