Fusion 360 - Sketch problem, Fully Constrained but not Fully defined (No Lock on Sketch)

This is a a small tip on how to turn a fully constrained sketch with som lines that are blue in to a fully defined sketch with all black lines and the lock on the sketch.
Hope it's helpful.

[@Wintergatan]

Cant say how grateful i am for this little video, i thought this was a mac bug, but your fix worked on mac aswell thank you!

[@KristianLaholm]

There are a lot more to be desired from the sketch engine in Fusion but with some "help" it can be guided. An I must say I like your "new" style of videos breaking down your design process.

[@WowRodg]

Wow, thanks a million times ! Exactly what happened to me ! I was searching like crazy. Every thing was fully constrain, nothing was able to move ! I just added a construction line, and boom ! 😃

[@KristianLaholm]

It can be a bit confusing and annoying, the sketch engine is getting better and better.

[@RaihanAndika-yp6eo]

thanks, really helped my problem! i think this is because fusion360 wants us to define the length between elements just a bit more before it can confidently set it as constrained

[@robocog]

That is an odd one, glad you found a way of convincing it Before it turned black - could any of the blue lines be moved? (it is what I usually do to check- followed by a ctrl z )

[@KristianLaholm]

No none of the lines can be moved, and I can't add more constrains as Fusion is giving me the "over constrained"-error. The example here was from a Facebook question, but I have stumbled on this problem a couple of times. Another way of solving the "problem" can be to save, close and reopen the file. It looks like Fusion then recalculates the sketch and it gets fully defined.

[@thatonesnowboarde]

right click the dotted lines inside the sketch and click fix/Unfix

[@KristianLaholm]

But if I want to go back and change a dimension I have to Unfix/Fix the line every time? The line is constrained but the sketch will not show up as fully defined (there have been changes to Fusion that will now better solve sketch problems likes this but it's not perfect).

[@4funrc11]

Thx. 👍 Yep, this has happened to me recently. Very puzzling behavior. 😃

[@KristianLaholm]

There is the reverse to, Fusion marks a line black as defined but it's not ... and then I move the line by mistake ... oops 😣

[@4funrc11]

@@KristianLaholm A-ha... I know, right. lol 😃

[@GargamelCZ]

:-D drawing the rhombic dodecahedron I came accross several issues, this was one of them, too bad this solution didn't work in my case (I'm doing a 3D sketch and there's nowhere to put extra lines)

[@KristianLaholm]

Constrains are not fully implemented with 3D sketching in Fusion. If you want to use constrains the sketch need to be on one sketch plane. Dimensions can be tricky with 3D sketches to, try to create constructions planes and keep sketches on planes.

[@apocalypticangell]

I'm not convinced you're not unintentionally adding constraints. It looks like you have auto constrain turned on, and adding those construction lines may be inadvertently adding the constraints you need to full constrain the sketch.

[@KristianLaholm]

To me if I add constrain with the lines and then delete the lines the constrains would be removed, and if I try to add constrain like Horizontal between corners Fusion gives me a red over constrained warning. Sometimes saving and reopening the file also make the sketch fullt defined without adding anything. And if I do the sketch in another "order of operation" the sketch gets fully constrained directly. I don't see this as a bug more a result of a software that needs to solve a multitude of problems getting stuck running in a circle.