git:20260911.25436b5 to git:20261005.2bc0998

- tags: ["fusion-360", "autodesk-fusion", "adsk-python", "parametric-cad", "cam-toolpaths", "claude"]

- # Autodesk Fusion (Fusion 360) AI Skill Guide (Claude)

- Autodesk Fusion (formerly Fusion 360) is a cloud-integrated parametric and direct modeling CAD/CAM/CAE/ECAD ecosystem. Claude operates as a Senior CAD Automation Specialist and Manufacturing Engineer, specializing in **Fusion Python API scripting (`adsk.core`, `adsk.fusion`)**, **Parametric Timeline diagnostic remediation**, **T-Splines organic surface conversion**, and **CAM 2.5D/3D adaptive toolpath optimization**.

- ### Fusion 360 Cloud-Hybrid Architecture

- │ Fusion 360 Architecture Core │

- │ │

- │ Design & Manufacturing Workspaces │

- │ ├── Parametric B-Rep Timeline & Direct Modeling Modes │

- │ ├── T-Splines Form Workspace (Subdivision to Solid B-Rep) │

- │ ├── CAM / Manufacturing (Adaptive Clearing & Post-Process) │

- │ └── Electronics (Eagle PCB & 3D Component Packaging) │

- │ │

- │ Developer & Cloud Subsystems │

- │ ├── In-Process Python 3.11 Execution Engine (`adsk` APIs) │

- │ ├── Autodesk Fusion Team Cloud Data Hub (Versioned F3D/F3Z)│

- │ └── Offline Storage & Local Cache Sync Daemon │

- ## Operational Capabilities & Agent Directives

-

- 1. **Fusion Python API Development**: Write robust, modular Python add-ins and standalone scripts utilizing `adsk.core` and `adsk.fusion` to automate feature creation, parameter tables, and export pipelines.

- 2. **Timeline Compute Error Remediation**: Diagnose Yellow (Warning) and Red (Compute Failed) timeline icons, resolving lost reference geometry, broken projected edges, and over-constrained sketches.

- 3. **CAM & Post-Processor Configuration**: Generate and inspect 2D/3D adaptive toolpaths, set spindle RPM and feed rates, and configure post-processor JavaScript scripts (`.cps`) for CNC controllers (Haas, Fanuc, GRBL).

- 4. **Cloud Hub & Sync Recovery**: Remediate stuck local upload queues, clear corrupted W.Cache stores, and manage multi-user team hub branching.

-

- ---

-

- ## Production Python Automation: Parametric Enclosure Box Generator

-

- Run this script inside Fusion 360 Script Manager (*Utilities $\rightarrow$ Scripts and Add-Ins*) to procedurally generate a parametric electronic enclosure box with a shell cavity and rounded corner fillets:

-

- ```python

- """

- Autodesk Fusion: Parametric Enclosure Box Generator

- Creates a fully constrained parametric box with Shell and Fillet features.

- """

-

- import adsk.core

- import adsk.fusion

- import traceback

-

- def run(context):

- ui = None

- try:

- app = adsk.core.Application.get()

- ui = app.userInterface

- doc = app.documents.add(adsk.core.DocumentTypes.FusionDesignDocumentType)

- design = app.activeProduct

- root_comp = design.rootComponent

-

- # 1. Setup User Parameters

- user_params = design.userParameters

- p_len = user_params.add("BoxLength", adsk.core.ValueInput.createByString("120 mm"), "mm", "Length")

- p_wid = user_params.add("BoxWidth", adsk.core.ValueInput.createByString("80 mm"), "mm", "Width")

- p_hgt = user_params.add("BoxHeight", adsk.core.ValueInput.createByString("40 mm"), "mm", "Height")

- p_thk = user_params.add("WallThickness", adsk.core.ValueInput.createByString("3 mm"), "mm", "Thickness")

-

- # 2. Create Base Sketch on XY Plane

- sketches = root_comp.sketches

- xy_plane = root_comp.xYConstructionPlane

- sketch = sketches.add(xy_plane)

- # Draw Center Rectangle

- lines = sketch.sketchCurves.sketchLines

- rec = lines.addCenterPointRectangle(adsk.core.Point3D.create(0, 0, 0), adsk.core.Point3D.create(6, 4, 0))

- # Add Dimensions

- sketch.sketchDimensions.addDistanceDimension(

- rec.item(0).startSketchPoint, rec.item(0).endSketchPoint,

- adsk.fusion.DimensionOrientations.HorizontalDimensionOrientation,

- adsk.core.Point3D.create(0, 5, 0)

- ).parameter.expression = "BoxLength"

- sketch.sketchDimensions.addDistanceDimension(

- rec.item(1).startSketchPoint, rec.item(1).endSketchPoint,

- adsk.fusion.DimensionOrientations.VerticalDimensionOrientation,

- adsk.core.Point3D.create(7, 0, 0)

- ).parameter.expression = "BoxWidth"

- # 3. Create Extrude Feature

- prof = sketch.profiles.item(0)

- extrudes = root_comp.features.extrudeFeatures

- ext_input = extrudes.createInput(prof, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)

- distance = adsk.core.ValueInput.createByString("BoxHeight")

- ext_input.setDistanceExtent(False, distance)

- extrude_feat = extrudes.add(ext_input)

- body = extrude_feat.bodies.item(0)

- # 4. Create Shell Feature (Hollow top face)

- top_face = None

- for face in body.faces:

- if face.geometry.normal.z > 0.9:

- top_face = face

- break

- if top_face:

- shell_faces = adsk.core.ObjectCollection.create()

- shell_faces.add(top_face)

- shells = root_comp.features.shellFeatures

- shell_input = shells.createInput(shell_faces, False)

- shell_input.insideThickness = adsk.core.ValueInput.createByString("WallThickness")

- shells.add(shell_input)

- ui.messageBox("Parametric Enclosure Box Created Successfully!")

- except Exception:

- if ui:

- ui.messageBox(f"Execution Failed:\n{traceback.format_exc()}")

- ---

-

- ## Technical Troubleshooting Matrix

-

- | Issue & Failure Signature | Root Cause Analysis | Diagnostic & Resolution Pathway |

- | :--- | :--- | :--- |

- | **Timeline Compute Failed (`Red Warning Icon`) on Extrude** | The underlying sketch profile lost its closed boundary or a referenced projected edge was deleted. | 1. Right-click the red Timeline feature $\rightarrow$ **Review Warnings**.<br>2. Right-click $\rightarrow$ **Edit Sketch**.<br>3. Inspect yellow detached projection points; re-constrain or delete and re-project geometry. |

- | **T-Spline Body Fails to Convert to Solid B-Rep** | Self-intersecting control frame vertices, non-manifold edges, or pinched star points ($>5$ edges). | 1. In Form workspace, run *Utilities $\rightarrow$ Repair Body*.<br>2. Set mode to **Auto Repair** to remove degenerate faces.<br>3. Toggle *Box View (`Alt + 1`)* to locate self-intersecting T-Spline faces. |

- | **CAM Toolpath Fails with `Empty Toolpath` Warning** | Tool geometry is too large to fit inside the pocket geometry, or stock boundary is outside model limits. | 1. In CAM Setup, verify Stock dimensions.<br>2. Reduce **End Mill Diameter** or enable **Rest Machining** with smaller stepover.<br>3. Lower the **Minimum Cutting Radius** in toolpath Passes settings. |

- | **Local Cache Sync Lockup (`Upload Pending` Loop)** | Corrupted offline SQLite cache or broken lock token in Autodesk local data store. | 1. Close Fusion 360.<br>2. Navigate to `%LOCALAPPDATA%\Autodesk\Autodesk Fusion 360\<ID>\W.Cache` and delete `.dirty` or lock files.<br>3. Relaunch Fusion with active internet connection. |

- ## Command Line Syntax & Configuration

-

- ```bash

- # Windows CLI: Launch Fusion 360 with Clean Cache / Safe Mode

- "C:\Users\%USERNAME%\AppData\Local\Autodesk\webdeploy\production\<BUILD_ID>\Fusion360.exe" -safeMode

-

- # Launch Service Utility to Repair / Reset Fusion Installation

- "C:\Users\%USERNAME%\AppData\Local\Autodesk\webdeploy\production\<BUILD_ID>\Fusion360ServiceUtility.exe"

-

- # macOS Launch Command

- open /Applications/Autodesk\ Fusion\ 360.app --args -safeMode

- ```

- ### Essential File & Directory Paths

- - **Windows Python Add-Ins**: `%APPDATA%\Autodesk\Autodesk Fusion 360\API\AddIns`

- - **Windows Python Scripts**: `%APPDATA%\Autodesk\Autodesk Fusion 360\API\Scripts`

- - **Windows Local Offline Cache**: `%LOCALAPPDATA%\Autodesk\Autodesk Fusion 360\<USER_ID>\W.Cache`

- - **macOS Python Add-Ins**: `~/Library/Application Support/Autodesk/Autodesk Fusion 360/API/AddIns`

- > **MANDATORY**: Python automation in Fusion must always check for valid geometry selections, wrap code in `try...except` blocks with `traceback.format_exc()`, and parameterize dimensions through `design.userParameters` rather than hardcoding magic numbers.