How to control Patterns on a Path

https://youtu.be/DCPI3UY-nGQ

Pattern on Path: Get Exact Spacing on Curved Designs

A pattern can look evenly spaced in Fusion and still be mathematically wrong. This matters when you create 12 holes, connect chain links, place rivets, or repeat slots along sheet metal.

Fusion Pattern on Path gives you control over repeated features and components, but the default drag handles often encourage guesswork. The techniques below show how to measure closed paths, prevent duplicate endpoints, orient components, and handle complex curved surfaces with better results.

Create a precise Fusion Pattern on Path

Use construction geometry to center the pattern

In the flange example, 12 holes need equal spacing around the part while staying centered between two arcs. The measured distance between the arcs is 0.6 inches, so an offset of half that value creates the correct centerline: 0.3 inches.

Create a sketch on the flat face, offset the outer loop by 0.3 inches, and convert the new loop to construction geometry. This path gives Pattern on Path a centered route for the holes.

Choose features or components

Fusion can pattern either features or components. Use features for geometry created inside a part, such as holes, cuts, and slots. Use components for separate objects, such as chain links or rivets in an assembly.

For the flange, select the hole feature. Then choose the construction loop as the path. Set the quantity to 12 and select Extent.

Treat the path as a measured element

A closed path needs a known total length when you want exact spacing. The standard Measure command may report one edge or two selected segments, but it may not combine every segment in the loop.

Dragging the blue manipulator until the pattern looks centered can leave small errors. Those errors can affect drawings, hole tables, fit, and later design changes.

Reveal the exact path length with Point Along Path

Set Point Along Path to proportional distance

Go to Construct > Point Along Path and select the complete construction path. Set Extent to Proportional, then set the distance to 1.

A proportional value runs from 0 to 1. A value of 0 places the point at the start of the path, while 1 places it at the end after traveling the full path length.

Switch to absolute distance

Change the extent setting from Proportional to Absolute. Fusion converts the ratio into a measured distance, revealing the full length of the selected path.

Record or copy this value.

*** Note: After publishing the video, viewers commented that if you double-click on the construction path, Fusion reports the total loop length down in the lower-right corner of the viewport. This is much quicker than having to do the Point Along Path solution. ***

Enter the value in Pattern on Path

Open Pattern on Path again and paste the measured length into the pattern’s Extent field. The instances now spread across the exact distance instead of following an approximate drag position.

The path length may change if the model changes later. Fusion does not reliably expose this absolute result as a stable parameter, so you may need to repeat the measurement after editing the shape.

Prevent duplicate endpoints on closed loops

Understand the overlapping instance

A closed path begins and ends at the same location. When Pattern on Path runs from 0 to 1, the first and last instances overlap.

That creates a confusing result. A quantity of 12 may show only 11 distinct holes because two holes occupy the same point. The pattern still contains 12 instances, but one is hidden directly beneath another.

Set the quantity one higher

For 12 visible holes, set the pattern quantity to 13. The extra instance fills the endpoint position and keeps the spacing mathematically even around the loop.

This approach may seem unusual, but it accounts for the duplicated start and end positions on a closed path.

Suppress the duplicate

Enable Suppression in the Pattern on Path dialog. Fusion adds a control box to each instance. Select the overlapping endpoint and suppress it.

The result is 12 visible, equally spaced holes. Suppression also keeps drawings, hole tables, and manufacturing views from reporting an unwanted duplicate.

Make patterns follow curves, assemblies, and sheet metal

Use Path Direction for rotating components

The Identical orientation keeps every copy aligned like the original object. That works for some straight patterns, but it often looks wrong on a curve.

Change the orientation to Path Direction when components need to rotate as they follow the route. Chain links usually need this setting so their position changes along the selected path.

Pattern chain links with known spacing

For the chain example, the pin-to-pin distance is exactly 1 inch. That measurement is more useful than the total loop length because each link must connect to the next one.

Set the object type to Components, select the chain-link assembly, and choose the loop as the path. Use Spacing with a 1-inch value, then adjust the quantity until the chain nearly closes.

By dragging the plus and minus arrows near the pattern manipulator, you can change the quantity of pattern instances.

Solve chain loops with Autodesk Assistant

Set a target loop length

Manual calculations become harder when a chain path includes circles, tangent lines, and arcs. In the demonstrated assembly, 60 chain links require a total loop length of 60 inches because the link spacing is 1 inch.

The driving sketch dimension is labeled D3. Autodesk Assistant is instructed to set D3 to the value needed for Sketch 1 to have a 60-inch loop length.

Let Fusion 360 calculate the dimension

Autodesk Assistant changed D3 from 16 inches to 15.5729 inches in the example. This value is not universal; it depends on that model’s geometry.

The calculation took about 1 minute and 43 seconds. That was faster than working through the belt-length math by hand.

Check the solver summary

The Assistant identified the shape as a two-circle belt with two tangent lines and two arcs. It applied a matching formula, updated the sketch, and verified that the final loop measured exactly 60 inches. Use this method when several geometric relationships control the path.

Pattern folded or unfolded sheet metal

Pattern On Path can repeat slot features on a folded sheet metal part. Select the features, choose an edge as the path, set the orientation to Path Direction, and adjust the quantity.

You can also unfold the part first, pattern the features along a straight edge, then use Refold Faces. Both methods can work. Choose the one that gives the cleanest control over the slot locations.

Slots that cross a bend may create poor results. Use Suppression to turn off those individual instances while keeping the rest of the pattern active.

Improve patterns on complex 3D surfaces

Pattern rivets along a curved edge

For a rivet component, select Components, choose the rivet, and select the perimeter path. Hold Control when selecting connected path segments so the route continues around the full edge.

Set the orientation to Path Direction and adjust the quantity. This works well when the edge curves mainly in one direction.

Know when Path Direction falls short

A single path can curve sideways and upward at the same time. Path Direction may align the rivets with the edge while leaving them slightly tilted from the surface.

That issue appears on organic shapes such as an airplane body. The rivets follow the edge, but they may not sit flush across the second curve.

Split the route into smaller patterns

For better contact, pattern rivets across shorter path segments. A quantity of 12 can cover one section, while additional copies handle the next sections.

Use Move/Copy to duplicate the rivet, then rotate and pattern each section to match the local surface contour. This takes longer, but it gives a more realistic result for visualization, fabrication, or 3D printing.

Conclusion

Reliable Fusion Pattern on Path results start with a well-defined path. Use construction offsets to center holes, Point Along Path to measure closed loops, and an extra instance with suppression to manage duplicate endpoints.

Choose features for holes and slots, components for chain links and rivets, and Path Direction when objects must rotate along a curve. For compound-curved surfaces, split the pattern into smaller sections and fine-tune each group.

Autodesk Assistant can solve difficult loop dimensions, while unfolded sheet metal can make slot patterns easier to control. After any major design change, refresh the path length and verify the final model before sending it to drawings, fabrication, or a 3D printer.