Dimension over-constrain sketch

[Anonymous]

Fusion 360 not doing what video shows. How to fix?  See vid.

[leowarren34]

Hi @Anonymous,

I'm leaning towards bug since I've been playing with your file for a while and are as perplexed as you are.

I recreated a near-identical sketch with the dimension you wanted and that didn't lock up like the other and behaved. I'm still wondering how the horizontal is locked with no dim or constraint I would think of that would cause a lockup.

Spot the difference between my sketch (right) and yours (left) besides the corner being locked or coincident:

[Anonymous]

Hi leowarren34

Thanks for taking a look at this, as I am only into the 6th learning project I really do not know enough to understand what you are referring to, kind of a drag as I want to learn fusion to be able to get shop plans for a storage cabinet I want to build and am not sure how this bug will impact that project when I feel I understand enough to create something on my own.

[HughesTooling · Accepted solution]

Not sure how it was created but you have a rouge tangent constraint on the top left fillet. Screencast below shows the problem, there are 2 tangent constraints on top of each other, one doesn't seem to highlight what it's tangent to. Normally if you hover over a constraint the geometry it constrains will highlight. Did you use the fillet tool to create this or circles and trim? @Phil.E  Any ideas?

Mark

[HughesTooling]

---

@Anonymous wrote:

Hi leowarren34

Thanks for taking a look at this, as I am only into the 6th learning project I really do not know enough to understand what you are referring to, kind of a drag as I want to learn fusion to be able to get shop plans for a storage cabinet I want to build and am not sure how this bug will impact that project when I feel I understand enough to create something on my own.

---

@Anonymous  As you're learning Fusion, a bit of advice. If possible avoid filleting in sketches and add them as a feature to the solid. You should try and keep sketches as simple as possible and they will be more predictable and efficient when you try changing dimensions.

Mark

[leowarren34]

@HughesTooling I completely overlooked filleting as a possible issue in the sketch, I think mostly due to the trouble that they can be I've made a habit to avoid them like the plague with very few exceptions, so caught me right out. 😁

[Anonymous]

I used the line tool to create the shape. I just tried to recreate it and this time I got to the desired result, no idea how the double tangent happened. Thanks for finding that at least now I know a little more about fusion.

[Phil.E · Accepted solution]

Thanks for the update. Did you perhaps use undo at some point?

As you learn Fusion 360, if you find it repeating for you, please let us know. Always glad to check on these things.

[Anonymous]

will do, thanks

[Phil.E · Accepted solution]

The reason for this is actually as-design. There is no bug here.

The two arcs at the top are tangent to each other, this explains the tangent icons and the overconstrained results, and the lack of repeating it. When these are tangent to each other, they cannot move apart.