I tried to locate a simple and clear method to created a 3D dome morel in fusion 360 without realising how complicated the topic can seem if not understood from basic concepts. This document captures my discovery and with the constantly evolving internet where things lately seems to disappear, I document them here more so for my own reference, but with the hope that it can be useful for my fellow tinkerers too. ^{1) 2)}

Designing a geodesic dome in Fusion 360 is a rewarding exercise in both geometric modelling and parametric design. Geodesic domes, popularized by Buckminster Fuller, are renowned for their structural efficiency and aesthetic appeal, making them a favourite for architectural, engineering, and maker projects. However, modelling such a structure in Fusion 360 presents unique challenges: the geometry is nontrivial, the need for parametric control is high, and the workflow must balance efficiency with editability. This comprehensive guide synthesizes the latest community best practices, trusted add-ins, scripting options, and native Fusion 360 workflows to help you create a fully parametric, editable geodesic dome model.

A geodesic dome is typically derived from an icosahedron —a polyhedron with 20 equilateral triangular faces. The process of creating a dome involves subdividing each triangular face into smaller triangles (increasing the “frequency”) and projecting the new vertices onto a circumscribed sphere. The frequency (notated as 2V, 3V, etc.) determines the number of subdivisions per edge and thus the smoothness and complexity of the dome.

• 2V Dome: Each edge of the icosahedron is divided into two segments, resulting in a relatively simple structure.
• 3V Dome: Each edge is divided into three segments, producing a denser, more spherical dome.
• Higher Frequencies: 4V, 5V, and beyond yield even smoother domes but increase modelling and fabrication complexity.

The choice of frequency impacts not only the appearance but also the number of unique strut lengths and the ease of assembly. For most Fusion 360 users, 2V and 3V domes strike a practical balance between buildability and aesthetics.

The process of subdividing and projecting triangles is rooted in geometric and trigonometric principles. Each new vertex is calculated by dividing the edges of the original triangle, then “normalizing” its position so it lies on the sphere's surface. This ensures all struts radiate from the center, preserving the dome's integrity.

Key Terms:

• Chord Length: The straight-line distance between two vertices on the sphere.
• Dihedral Angle: The angle between two adjacent triangular faces, critical for connector design.
• Strut Types: Different lengths of connecting members, determined by the frequency and subdivision method.

Understanding these concepts is essential for maintaining parametric control and ensuring the model's accuracy.

Before modeling, it's crucial to select a workflow that matches your goals for parametric control, efficiency, and downstream use (e.g., fabrication, visualization). The table below compares the main approaches:

Native tools offer the greatest flexibility and parametric control, while scripts and add-ins can accelerate the process but may limit editability. Downloadable templates provide a quick start but often lack full parametric features. Manual assembly is educational but time-consuming for complex domes.

Before modelling, determine the strut lengths and angles for your chosen dome frequency and diameter. Trusted online calculators, such as those from Zip Tie Domes, provide detailed breakdowns for 2V, 3V, and higher-frequency domes, including strut lengths, panel dimensions, and connector angles.

1. Zip Tie Domes Calculators: 2V Calculator, 3V Calculator, Calculator Index
2. SimplyDifferently.org: Offers mathematical notes and calculators for various dome types.
3. DomeCalc (Python Script): For advanced users, DomeCalc computes optimal strut lengths and material usage.

Tip: Record the strut lengths and angles for reference during modelling. For parametric workflows, plan to input these as user parameters in Fusion 360.

Several Autodesk Community threads and YouTube tutorials share .f3d files for 2V and 3V domes. These can be used as starting points or for study:

• Autodesk Forum: Geodesic Dome 2V/3V (includes .f3d attachments)
• YouTube: 2V Icosahedron Dome
• YouTube: 3V Geosphere Workflow

Note: While templates are convenient, they may not be fully parametric or editable. Always check the timeline and parameters before adapting them for your project.

This section details a robust, parametric workflow using only Fusion 360's native tools, ensuring maximum editability and control. The process is illustrated for a 2V or 3V dome but can be adapted for other frequencies.

Step 1: Create User Parameters

- Open the Parameters dialog (`Modify > Change Parameters`). - Define key parameters:

1. `Dome_Diameter` (e.g., 3000 mm)
2. `Dome_Radius` = `Dome_Diameter / 2`
3. `Strut_A_Length`, `Strut_B_Length`, etc. (from calculator)
4. `Frequency` (e.g., 2 or 3)

Why? Using parameters ensures the dome can be resized or reconfigured by changing a single value, propagating updates throughout the model.

Step 2: Anchor the First Sketch to the Origin

- Create a new component named “Geodesic Dome.” - Start a new sketch on the XY plane. - Draw a construction circle with a radius of `Dome_Radius`, centered at the origin. - Fully constrain the sketch: all lines should turn black, not blue, to avoid downstream errors.

Tip: Always anchor your first sketch to the origin for stability and symmetry.

Step 3: Sketch the Icosahedron Vertices

- Use geometric construction or reference coordinates to plot the 12 vertices of an icosahedron on the sphere. - For a 2V dome, you can use the method of stacking polygons at different heights (as described in the Autodesk forum) or use mathematical coordinates from calculators.

Step 4: Connect Vertices to Form Triangles

- Draw lines connecting the vertices to form the 20 triangular faces of the icosahedron. - Use construction lines and constraints to ensure all triangles are equilateral and the structure is symmetrical.

Tip: For higher frequencies, you may prefer to script this step or use a downloadable template as a base.

Step 5: Subdivide Each Triangle

- For a 2V dome, divide each edge of the base triangle into two segments. - For a 3V dome, divide each edge into three segments. - Use the “Point” tool to mark division points, then connect these to form smaller triangles within each face.

Step 6: Project Subdivision Points onto the Sphere

- For each new vertex, calculate its position so it lies on the sphere's surface (normalize its distance from the origin to `Dome_Radius`). - In Fusion 360, this can be done by:

1. Creating construction lines from the origin through each subdivision point.
2. Using the “Point at Distance” tool or parametric constraints to set the length of each line to `Dome_Radius`.
3. Placing a point at the end of each line.

Why? This ensures the dome's surface is truly spherical, not flat or distorted.

Step 7: Create 3D Sketches or Construction Geometry

- Use 3D sketches (or multiple 2D sketches on offset planes) to connect the projected points, forming the triangular grid of the dome. - For each triangle, connect the three vertices with lines.

Step 8: Model Struts as Components

- For each unique strut length (A, B, etc.), create a new component named “Strut_A,” “Strut_B,” etc. - Sketch a line of the correct length, then use the “Pipe” or “Sweep” tool to create a solid or hollow strut. - Use parameters for length and diameter to maintain editability.

Step 9: Assemble the Dome Using Patterns and Joints

- Use the “Pattern on Path” or “Circular Pattern” tools to duplicate struts around the dome, referencing the construction geometry. - Use “Joints” or “As-Built Joints” to connect struts at vertices. For large assemblies, consider grouping struts into subassemblies (e.g., pentagons, hexagons) for easier management.

Tip: Avoid over-constraining the assembly. Use rigid groups or subassemblies to simplify joint management.

Step 10: Model Triangular Panels (Optional)

1. For a panelized dome, create a new component for each unique triangle type.
2. Use the construction geometry to define the panel's shape, then “Extrude” to the desired thickness.
3. Use the “Thicken” tool for surface-based panels.

Step 11: Design Connectors or Hubs

1. If using hubs, model them as separate components with holes or slots for struts.
2. Use parameters to control hub size and hole spacing.
3. For direct strut-to-strut connections, ensure the ends are cut at the correct dihedral angles (use the “Cut” or “Combine” tools).

Step 12: Add Doors, Windows, and Reinforcements

1. Identify triangles or panels to be replaced with doors or windows.
2. Create new components for these features, referencing the existing geometry for alignment.

Step 13: Maintain Parametric Control

1. Throughout the process, reference user parameters for all critical dimensions.
2. Use named parameters for strut lengths, dome diameter, panel thickness, etc.
3. Test the model by changing the dome diameter and verifying that all geometry updates correctly.

For users seeking automation or higher frequencies, scripts and add-ins can accelerate the process. Fusion 360 supports Python and JavaScript APIs for custom scripting.

Popular Script Repositories:

1. [robotecht/Fusion360-Scripts](https://github.com/robotecht/Fusion360-Scripts): General scripts for patterns and geometry (not dome-specific).
2. [d3v-null/DomeCalc](https://github.com/d3v-null/DomeCalc): Python script for calculating dome strut lengths and optimizing material usage.

Installation Steps:

1. Download the script or add-in from GitHub or the Autodesk App Store.
2. Place the files in the appropriate folder:
   1. Windows: %appdata%\Autodesk\Autodesk Fusion\API\Scripts (for scripts) or …/AddIns (for add-ins)
   2. macOS: ~/Library/Application Support/Autodesk/Autodesk Fusion/API/Scripts or …/AddIns
3. Restart Fusion 360.
4. Open UTILITIES > Scripts and Add-Ins, select the script, and click “Run”.

Usage: Most scripts generate geometry as bodies or components. Review the script's documentation for parameter options (e.g., dome radius, frequency, strut adjustment).

Limitations: Script-generated domes may not be fully parametric or editable after creation. For maximum flexibility, use scripts to generate base geometry, then convert to parametric components as needed.

1. Autodesk Community threads often include .f3d files for various dome frequencies.
2. [TurboSquid](https://www.turbosquid.com/Search/3D-Models/free/geodesic-dome) and [Sketchfab](https://sketchfab.com/tags/geodesic-dome) offer free 3D models, though these may require conversion and cleanup for parametric use.

Tip: When using downloaded files, inspect the timeline and parameters. Convert static bodies to components and add user parameters for future edits.

Fusion 360 offers several methods for exporting clean DXF files, essential for fabrication:

1. From 2D Sketches: Right-click the sketch in the Browser, select “Save as DXF”.
2. From Flat Patterns (Sheet Metal): Use the “Create Flat Pattern” tool, then export as DXF from the Flat Pattern workspace.
3. From Planar Faces: Create a sketch on the planar face, project the edges, finish the sketch, and export as DXF.

Best Practices:

1. Use the “Project” tool to ensure all necessary geometry is included in the sketch.
2. Keep sketches simple and fully constrained.
3. Verify exported DXF files in a viewer or CAM software before fabrication.

Tip: For panelised domes, export each unique triangle as a separate DXF for cutting.

1. Use the “Drawing” workspace to create 2D documentation of the dome, including part lists and assembly diagrams.
2. Annotate strut lengths, panel dimensions, and connector details for clarity.

1. For strut or panel fabrication, use the “Manufacture” workspace to generate toolpaths for CNC routers, plasma cutters, or waterjets.
2. Ensure all components are properly named and organized for efficient CAM programming.

1. User Parameters: Reference parameters for all critical dimensions.
2. Component Patterns: Use “Pattern on Path,” “Circular Pattern,” and “Mirror” tools to efficiently duplicate geometry while maintaining parametric links.
3. Assemblies: Organize struts and panels into subassemblies (e.g., pentagons, hexagons) for easier management and joint placement.

1. Under-Defined Sketches: Always fully constrain sketches to prevent instability and errors during updates.
2. Floating Geometry: Anchor the first sketch to the origin for stability.
3. Over-Constrained Assemblies: Use rigid groups or subassemblies to reduce the number of joints and simplify updates.
4. Surface vs. Solid Modeling: For panelized domes, start with surfaces, then use “Thicken” or “Stitch” tools to create solid bodies.

1. Gaps or Non-Watertight Geometry: Ensure all vertices are projected onto the sphere and all faces are closed. Use the “Stitch” tool to seal surfaces before converting to solids.
2. Pattern Distortion: When using patterns on curved surfaces, ensure the base geometry is correctly aligned and constrained. For complex patterns, consider scripting or manual placement.
3. DXF Export Issues: Clean up sketches, remove unnecessary lines, and verify units before exporting. Use the “Project” tool for accurate 2D outlines.

Recommendation: For most users seeking a balance of efficiency and editability, the native parametric workflow is optimal. Scripts and add-ins are valuable for rapid prototyping or high-frequency domes, while templates are best for visualization or as learning aids.

• YouTube: 2V Icosahedron Dome (No Math): Kristian_Laholm's tutorial demonstrates a geometric approach using only one dimension and Fusion 360's native tools.
• YouTube: 3V Geosphere Workflow: Kristian_Laholm's 3V tutorial covers the base geometry for a 3V dome.
• Autodesk Forums: Threads such as Geodesic Dome 2V/3V and Triangle Pattern on a Dome provide community insights, downloadable files, and troubleshooting advice.

1. Define Parameters: Set dome diameter, radius, and strut lengths using user parameters.
2. Create Base Sketch: Draw a circle at the origin, fully constrained.
3. Plot Icosahedron Vertices: Use geometric construction or calculator coordinates.
4. Subdivide Triangles: Divide each edge into two, connect points to form smaller triangles.
5. Project Points to Sphere: Use construction lines and parametric constraints.
6. Build Struts: Model each unique strut as a component, referencing parameters.
7. Assemble Dome: Use patterns and joints to position struts, forming the dome.
8. Add Panels/Connectors: Model panels and hubs as needed, using parametric dimensions.
9. Export for Fabrication: Use the Project tool and Save as DXF for each panel or strut.
10. Refine and Document: Add doors, windows, and create assembly drawings as required.

Modeling a geodesic dome in Fusion 360 is a multifaceted process that combines geometric insight, parametric modeling, and assembly management. By leveraging Fusion 360's native tools, trusted calculators, and community resources, you can create a fully editable, fabrication-ready dome model tailored to your specifications. Scripts and add-ins offer speed for advanced users, while downloadable templates provide a quick start for visualization or study. Maintaining parametric control, organizing assemblies, and following best practices for DXF export ensure your design is robust, adaptable, and ready for real-world construction.

Whether your goal is architectural innovation, educational exploration, or practical fabrication, this guide equips you with the knowledge and workflow to succeed in modeling geodesic domes in Fusion 360. For further learning, engage with the vibrant Fusion 360 community, experiment with scripts, and explore the wealth of tutorials and templates available online. With careful planning and attention to detail, your geodesic dome project will stand as a testament to both geometric beauty and engineering precision.