I am trying to get an AI to help me render some parts I want to create in CAD. I asked Claude to summarize what was done in trying to use the MCP connector to Fusion 360 - let's say a lot of man hours to get nowhere. Claude believes the parts are too complex. The parts were very simple : a simple box with a cutout step and a flange running around the stepped edge: I got Claude to write a report about what was not acheived....

Setup (2+ hours)

Not straightforward. No official integration despite announcements. Tried two community bridges:

fusion360-mcp-bridge (ndoo): Failed with Python env conflicts
fusion360-mcp-server (faust-machines): Eventually worked after manual config debugging

Required: Terminal comfort, virtual environments, config file editing, multiple restarts.

What Worked

✅ Basic Python execution in Fusion
✅ Sketch creation (2D geometry)
✅ Simple extrusions
✅ Camera control
✅ Property queries (dimensions, mass)

What Failed

❌ Complex multi-body assemblies
❌ Sheet metal features (flanges, bends)
❌ Body management (unexpected merges)
❌ Boolean operations (offset, shell)
❌ Iterative refinement

The Real Problem: Code-Based CAD is Hard

Test case: Create a stepped sheet metal firebox (two sections with flanges)

Three attempts, all failed:

Nested boxes → wrong geometry
Flanges + walls → bodies merged incorrectly
Solid block + cutouts → removed needed features

Root cause: Traditional CAD is visual and interactive. Code-based CAD requires:

Exact API knowledge without visual feedback
Managing object references programmatically
Predicting results without seeing intermediate steps
I couldn't see the Fusion window, only user screenshots

Best/Worst Use Cases

MCP Excels:

Simple parametric parts
Repetitive batch operations
Analyzing existing geometry
Automation scripts

MCP Poor Fit:

Complex assemblies
Sheet metal design
Iterative/exploratory design
Learning while building
One-off custom parts

Better Alternatives for This Project

For the firebox, faster/better approaches:

Step-by-step guidance (user clicks, I instruct)
Traditional 2D fab drawings → send to shop
Manual Fusion with visual feedback

MCP added complexity without value here.

The Learning Problem

Critical: My learning doesn't persist between conversations. Tomorrow's user gets a "fresh" Claude. This session's lessons help nobody else. Fundamental LLM limitation.

Ratings

Setup difficulty: 7/10
Basic capabilities: 8/10
Complex modeling: 3/10
Documentation: 4/10
Value for typical users: 4/10
Value for automation: 7/10

Recommendations

Don't use if:

Creating one-off custom parts
New to CAD
Need sheet metal features
Time-sensitive

Do use if:

Automating repetitive tasks
Creating parametric families
Comfortable with Python/APIs
Batch operations

For Anthropic/Autodesk:

Need official integration (community bridges are fragile)
Better error messages
Visual feedback loop essential
Simplified setup
Sheet metal API examples

Bottom Line

Promising but immature. Works for specific automation but isn't ready to replace interactive CAD. For custom one-off parts, traditional Fusion is faster and more reliable.

Session results: 3 hours, 15+ bodies created, 0 fabrication-ready models. High learning value about limitations.

Current recommendation: Wait for official integration, or use only for automation where scriptability outweighs lack of visual feedback.

u/Fizxguy

Claude + Fusion 360 MCP Integration: Real Use Case Report