Speed Modeling a Straight Bevel Gear in Fusion Using the SpurGear Add-In
Creating custom bevel gears in Autodesk Fusion doesn't have to be complex. In this tutorial, we’ll show you how to speed-model a straight bevel gear using Fusion’s built-in tools and the SpurGear Add-In. Whether you're a mechanical designer, hobbyist, or CAD enthusiast, this guide will walk you through a practical and quick workflow to prototype a bevel gear without diving deep into advanced gear calculations.
Why Use the SpurGear Add-In?
Fusion’s SpurGear Add-In generates a parametric spur gear with customizable settings. By combining this with solid modeling tools like Loft and Revolve, we can adapt it into a bevel gear concept—perfect for rapid design iterations or 3D printing test fits.
Step 1: Sketch the Shaft
Start by creating a sketch on a vertical construction plane. Draw a rough two-point rectangle as your framework. This rectangle helps define the area where we’ll sketch the profile of the shaft.
Sketch loosely at first—don’t worry about precision. You can add dimensions later to fully define the geometry. Once you’ve drawn the profile lines, use the Dimension tool to lock in values. Black lines mean your sketch is fully constrained; blue lines are still flexible.
Fusion adds constraints automatically while sketching. You can hover over constraint symbols to understand their function—this helps as you fine-tune your design.
Tip: Use arcs and trimming to refine the shaft’s shape. Oversketching and cleaning up afterward is often faster than trying to get it perfect from the beginning.
Step 2: Revolve the Shaft
Once you have a closed sketch profile, use the Revolve tool to turn it into a 3D shaft. Select the profile, choose the axis, and hit OK.
To add shaft features like cutouts or slots, apply an appearance to the face you’ll sketch on—it makes visibility easier. Project geometry from previous sketches to ensure the new sketch stays linked to any updates.
Use the Trim tool and dimensions to finalize the shape, then use Extrude, Fillet, and Circular Pattern to complete the details. Be sure to create new bodies when necessary to maintain flexibility during modeling.
Step 3: Generate the Gear with the SpurGear Add-In
Go to the Utilities tab and open Scripts and Add-Ins. Launch the SpurGear add-in and set your parameters. For this example:
Module: 4
Pitch Diameter: 96 mm (auto-calculated)
This places a standard spur gear component at the origin. Use Point to Point Move to align the gear with your shaft. Avoid using Joints—we’re not creating a mechanical assembly here, but rather a quick concept.
Once in place, expand the Spur Gear timeline and delete unnecessary elements:
Remove the full gear pattern
Delete the base solid
Keep a single gear tooth
Rotate the remaining tooth to match your desired bevel angle—for example, -45 degrees.
Step 4: Loft the Tooth to the Shaft
Create a 3D sketch using a vertical construction plane. Sketch two intersecting lines:
One from the center of the shaft (as a construction line)
One angled line (e.g., 135 degrees) from the gear tooth center
Use the intersection point of these lines as your loft guide.
Activate the Loft tool and select the gear tooth face as your starting profile, then select the intersection point as your endpoint. Set the operation to Join, but temporarily hide the shaft body before confirming to avoid merging with the wrong part.
Use Fillet to round off edges if needed, then pattern the lofted feature using Circular Pattern around the central axis. A full 360° distribution ensures even spacing.
Step 5: Final Adjustments and Clean-Up
After the gear teeth are patterned, you might notice an open area at the back. Use Loft again to fill this gap—select the rear profile and loft it up to a placed point.
Perform a Section Analysis to verify geometry quality. If needed, flip the cut direction to inspect the correct side.
Flatten the gear’s top using a Center Rectangle and Extrude Cut. This creates a clean surface for the final hole cut.
Sketch a circle on this flat face and Extrude Cut through the body. Avoid setting a fixed cut distance—use the To Object setting instead for a more robust, parametric design.
Why This Workflow Works
This tutorial focuses on speed and flexibility, using a mix of Fusion’s native modeling tools and the SpurGear Add-In to create a concept for a straight bevel gear. While it doesn’t follow strict component management or parametric best practices, it’s ideal for fast iterations, test prints, or creative exploration.
You can always refine this model for production later—split into components, add materials and appearances, or define proper joints and motion studies.
Final Thoughts
This method is perfect for rapid concept development. With just a few key tools—Sketch, Revolve, Loft, and the SpurGear Add-In—you can quickly model a functional straight bevel gear in Fusion.
Chapters:
00:10 Fusion Sketching: How to Create a 2-Point Rectangle
00:37 Make a Sketch for Revolve in Fusion (formerly Fusion 360)
00:48 Add Parametric Dimensions to a Sketch
00:58 Understand Sketch Color: Blue vs Black Lines
01:19 Automatic Sketch Constraints in Fusion
01:33 Draw and Dimension an Arc
02:10 Trim Tool in Fusion: Clean Up Sketch Lines
02:48 How to Fully Define a Sketch with Constraints
03:06 Refine Sketch and Use the Revolve Tool
03:28 Apply an Appearance to a Face in Fusion
03:52 Project a Sketch for Linked Geometry
04:50 Extrude a New Solid Body from a Sketch
05:14 How to Add a Full Round Fillet
05:29 Create a Parametric Circular Pattern
05:59 Model a Bevel Gear Head in Fusion
06:20 Generate Gears with the Spur Gear Add-In
07:00 Use Point-to-Point Move for Component Placement
08:03 Modify the Spur Gear Component
08:38 Rotate a Body Precisely in Fusion
09:14 Set a New Pivot Point for Rotation
09:40 Create a 3D Sketch for Complex Geometry
10:10 Add a Construction Line in 3D Sketch Mode
11:00 Loft to a Point for Tapered Geometry
11:52 Apply a Parametric Fillet
12:08 Create a Full Circular Pattern (Full Distribution)
12:39 Loft to a Point at Vertex
13:15 Use Section Analysis to Inspect Your Model
13:44 Set Up an Offset Plane in Fusion
14:18 Extrude Cut the Top Using a Center Rectangle on an Offset Plane
14:59 Cut a Hole to the Bottom Using a Circle Sketch
15:37 Add Appearance and Finalize Your Gear Project