Rotating ellipse sketch

[Torymiddlebrooks]

Hello,

I am having issues constraining an sketch involving 2 ellipses and rotating them.

I am essentially making a quarter note (skewed ellipse with a line up one side) and I want to rotate it to make the line point down but when I rotate the sketch everything is fine until I move it past the 180. I can mirror it but I shouldn't have to.

This is a the sketch: https://a360.co/3NtHvkf

[jhackney1972]

Edit your sketch and place a Coincidence between the center of the ellispes and the origin and then you can modify the angle to suit.  Remember, you cannot dimension a sketch angle to 0 degrees.  If you want this, delete the angle and add a horizontal sketch constraint to the ellipse axis.

[hamid.sh. · Accepted solution]

Is this what you're trying to do (constrained so it rotates without distortion)?

I made the line with a 3 point rectangle so automatic relationships are not horizontal/vertical but perpendicular and parallel (i.e. relative between entities), then made one corner coincident to the ellipse and one to 30° line:

But still it may happen that during rotation Fusion swaps between two possible solutions and rectangle go outside of ellipse.

By the way, shouldn't you make the line tangent to the ellipse to avoid this small area and have smooth shape?

[TheCADWhisperer]

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@Torymiddlebrooks wrote:

I am having issues constraining an sketch involving 2 ellipses...

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There is only one ellipse in your sketch.

There are two possible solutions to Offset of an ellipse.

True mathematical ellipse by selecting near major or minor axis.

Equal distant offset spline (not mathematical ellipse) by selecting away from major or minor axis (which is what you have in your sketch.

Having said that, your true Design Intent is not clear to me.

[Torymiddlebrooks]

Hello,

So, I wanted the interior ellipse because with it I could make that either a quarter note (filled) or a half or whole note (center missing).

The intent is to have a single sketch that I can extrude in different combos to get different notes. The reason I want a sketch is that I need to modify groups of notes to make them eight, sixteenth and to connect the notes with a beam.

The reason I don't have it tied to the origin is that it will be placed on a musical staff. 

I have updated the file so you can see what the end result should look like, but right now I copy the extrusion and rotate it instead of doing it via a sketch.

[Torymiddlebrooks]

Your note about constraining the rectangle to the ellipse better was actually the solution.

I used a tangent to connect the rectangle to the ellipse and then coincident'd (it's a new word) the corner of the rectangle to the ellipse and now I can spin it for days.

I have updated my test file for others to see the work.