Adding dimension to sketch offset feature incorrectly over-constrains

[Scoox]

I've experienced this bug many times but there's always a workaround and I was too lazy to report it, but today is the day. Here are the steps required to reproduce the problem:

1. Create a sketch
2. Draw a rectangle
3. Use the Offset tool under Modify to create a bigger rectangle around the rectangle from step 2
4. Try to dimension on of the sides of the outer (offset) rectangle

Expected result: Dimension added without issues.

Observed result: Fusion 360 reports over-constraining, as per attached screen capture.

[jhackney1972]

Since it is an Offset of the inside rectangle, it is over constrained.  If you do the same process and dimension the inside rectangle, you will notice the outside rectangle will be fully constrained (change color).  This is a normal process.

[jhackney1972]

Here is a short Screencast showing what I mentioned above. 

[Scoox]

Thanks for chiming in. I'm probably missing something but I can't see how it's over-constrained. The lines are blue, so the drawing isn't fully constrained to begin with. Logically and intuitively, if the offset is known, it doesn't matter which rectangle bears the dimensions.

[HughesTooling]

Fusion does not allow the offset to drive the source, that's why it shows as overconstrained.

Mark

[Scoox]

If that's the case by design, the warning message is misleading. It should say something like what you just said, "Fusion does not allow the offset to drive the source". As far as I know it is logically impossible to over-constrain a drawing that is not fully constrained by adding just one dimension. Two dimensions? Maybe, but not one.

Besides, if I pull the offset rectangle with the mouse, the source rectangle follows, which means the offset can drive the source. I can also attach a construction line between two sides of the offset rectangle (see screen cap below), dimension the construction line and that works too, which proves the offset can drive the source without issue.

[TheCADWhisperer]

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@Scoox wrote:

Thanks for chiming in.

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Whenever I see someone use sketch Offset - I wonder if Thin Feature or Shell would have perhaps been an alternative (better?) technique.  Just chiming in too.

[Scoox]

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@TheCADWhisperer wrote:

Whenever I see someone use sketch Offset - I wonder if Thin Feature or Shell would have perhaps been an alternative (better?) technique.  Just chiming in too.

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Obviously there are many ways to skin a cat. I just thought this was a bug so I decided to report it. Even if sketch offset is not all that useful, since it's there it might as well work as expected.