I'm working on a model in Fusion 360 that has part of the 2d sketch duplicated with the "Rectangular Pattern" tool. If I try resizing the original object, the duplicates update as expected. If, however, I try applying a fillet to the object, the pattern constraint is immediately lost and the duplicates don't update. I'm not seeing any error/warning, but I'm assuming it's running into a similar issue as if you were to delete a line that was part of the duplicated pattern (doing that shows a warning "Deleted geometry is part of a pattern, suppressed the instance or dissolved the pattern.")

Is there a way to alter the object (specifically apply a fillet) and have the duplicates automatically update? I've done a bit of searching around and I found some suggestions saying that patterns should generally be done on the 3d model instead of the 2d sketch, but in my case I'd like to keep this in the 2d world since there are other sketch pieces that are based on the duplicated portion.

Here is a simplified version of the problem I'm running into:

  1. Start with a simple rectangle

Basic rectangle

  1. Using the "Rectangular Pattern" tool in the sketch menu, select the rectangle and create a pattern

Duplicated rectangle

  1. Using the "Fillet" tool in the sketch menu, click on a corner of the original rectangle. Notice that the "Rectangular Pattern Constraint" icon is no long below the original rectangle.

Start applying a fillet to the original rectangle

  1. Finish applying the fillet. Notice that none of the duplicate rectangles have been updated.

enter image description here

  • 3
    $\begingroup$ I'm voting to close this question as off-topic because even though Fusion 360 is a program suitable for 3D modeling, this problem is not specific to 3D modeling. $\endgroup$
    – fred_dot_u
    Commented Jun 27, 2019 at 9:36
  • $\begingroup$ I was a bit hesitant to ask the question since it wasn't directly 3D printing related (though, the part will eventually be printed...). I read through the on-topic help page and it seemed to suggest that 3d modeling questions are considered on-topic (in the "Additional Topics" section). Here is the link to that page: 3dprinting.stackexchange.com/help/on-topic $\endgroup$
    – Pak
    Commented Jun 27, 2019 at 21:54
  • $\begingroup$ I'd expect that one would have more success with a Fusion 360 specific forum or CAD related forum, although I appreciate that F360 is a valid tool for 3D modeling. $\endgroup$
    – fred_dot_u
    Commented Jun 27, 2019 at 22:04
  • $\begingroup$ That's likely true. I usually like to start with stackexchange before branching out. I'll admit this question might require a much deeper understanding of the quirks of Fusion than one might expect to find here. $\endgroup$
    – Pak
    Commented Jun 27, 2019 at 22:12

1 Answer 1


In some CAD packages, this is exactly what I would expect. Models are constructed by applying operations in a specific order. The fillet is a separate operation, and is not part of the base rectangle.

The base rectangle is defined. You pattern the base rectangle. You define a fillet using the base rectangle as the reference. The fillet affects only that one rectangle.

OTOH, when you modify the base rectangle all are changed because the base rectangle is defined before the patterning operation.

If you can apply the fillet before the patterning, it may work as you wish.


Not the answer you're looking for? Browse other questions tagged .