What are differences between black lines and blue ones ?

[Anonymous]

Hello,

I beginner in Fusion 360.

What are the differences between the black lines, and the blue ones ?

And how to manage/set them ?

In this example, the 3 vertical "lines" are in reality 3 giant circles.

2 are black, and 1 is blue ! (why ?)

Black lines seem don't really work about magnet :

To select the centre of this circle, I can't find the magnet between the black vertical "line", and the lower circle.

The little horizontal line was made after from the centre, but finally don't touch the vertical "line" ...

[Anonymous]

I did e new project to test :

When I create a circle,

sometime the circle are black, and don't work than I expect.

sometime the circle is blue, and work well.

How to create all time a blue circle ?

[Anonymous]

To make a blue circle, that work better to no use the centre of the document, and then, move it ! (bug ?)

Bur finally, blue circles don't work all time ...

Here (new project)

The 3 verticals "lines" are 3 circles 81mm 80mm 79mm

The circle showed is a 1mm one

Impossible to select the intersection between this circle and the vertical "line" in the middle !

That work often on other circles with other sizes, but not here 😞

Bug ?

[davebYYPCU]

Easy part first, 

Black circles have a size, and the centre point is locked by dimension or constraint.

Click hold and drag on black circle it can’t move.

Blue circles do not have all those things,

click hold and drag blue circle it moves or changes size.

Black Geometry is not the same as black dimension indicators.

Lots of 1mm circles on inside centre and outside circles will make for complicated sketch, 

keep sketches simple.

Might help.....

[TrippyLighting]

If you have not done so, please go through the tutorials in the Support and Learning section. You'l likely have questions but will have a better foundation to ask those.

[Anonymous]

Right, I only did "Getting Started" ...

And English is also not my natural language.

But many things already make me crazy.

But I need to practice at least a bit !

I do a 82mm circle, sometime it's black (I see it centred on the document), sometime it's blue ...

Sometime circles have intersection detect, sometime not.

Very difficult to understand how work a program if the program seem to do random things ...

[TrippyLighting · Accepted solution]

It doesn't do random things.

Fusion 360has different viewport environments, which you can change through the little menu bar at the bottom-center of the Fusion 360 window.

What the line colors mean is different in these environments. Blue lines mean that the sketch object is not fully constrained and dimensioned also sometimes referred to as not fully defined.

A sketch item will turn from blue to black as soon as it is fully defined.

So when you start sketching a circle and it snaps to the sketch origin, it will be constrained to that sketch origin, but will still be blue. When you then dimension it it will turn black.

However, circles sketched somewhere else on the sketch plane will remain blue, even when you dimension them, because the center point of the circle is not defined. So you'll have to constrain it to "something" or dimension it or both.

[Anonymous]

Thank you !

But is there a solution to switch this mode ? (black/blue)

In doing all time the same,

Many 82mm circles centred on the document are black,

All 82mm circles not centred on the document are blue ...

My sketches are not so complicated !

If Autodesk is not able to do so simple things, the software don't interest me ...

To test, I draw a cap for lens (82mm)

A part work as a spring.

I wanted to do this form, but have to remove the 3 red cross.

Impossible because Fusion is not able to find intersection between 2 circles !

[TheCADWhisperer]

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@Anonymous wrote:

1. But is there a solution to switch this mode ? (black/blue)

Many 82mm circles centred on the document are black,

2. All 82mm circles not centred on the document are blue ...

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1. Yes, there is a simple solution, File>Export and then Attach your *.f3d file here for demonstration.

2. STOP here - and File>Export and then Attach your *.f3d file here at the very first sign of trouble (blue geometry not turning black (fully defined)).

[Anonymous]

Ok !

I fully understood by "FULLY constrained"

Thank you 😉

Now I have to learn about "constrains" 🙂

So all of this don't explain why Fusion is sometime able to find intersection between 2 circles, and sometime not ...

[TrippyLighting]

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@Anonymous wrote:

Thank you !

But is there a solution to switch this mode ? (black/blue)

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Yes, I had explained that already!

Fully constrain and dimension you sketches. Do you understand what a "constraint" is ?

[Anonymous]

Just because this forum don't reply in a tree ... (answer to someone else)

I understood ...

[Anonymous]

My draw work well with 4mm circles ! (but impossible with 1mm circles ...)

So strange ...

[TheCADWhisperer]

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@Anonymous wrote:

My draw work well with 4mm circles ! (but impossible with 1mm circles ...)

So strange ...

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File>Export and then Attach your *.f3d file here and end all doubt.