Substracting a thin rectangle from an ellipse is not working properly?

[finitystone]

Hi,

I try to substract a thin rectangle (blue) from an ellipse (red). The desired result should be the ellipse with a thin cut out (where rectangle lies over the ellipse), but what it gives me is a crashed form. I read through this forum and tried many advices (creating curves before substraction, changing fill mode after substraction) but nothing seems to work for me. Do you have any suggestions *hope*?

I attached a  document below.

substract_rectangle.afdesign

[Komatös]

Hello and welcome to the forums, @finitystone

I hope my solution is what you expect.

I have saved the history for better understanding.

substract_rectangle _ with history .afdesign

[finitystone]

That's magic! Many thanks to you, it works as exptected. To be honest never mind that way to go.

[Old Bruce]

I took the blue rectangle and converted it to a curve. I then added a couple of points on the rectangle just outside the circle and moved the farthest away from the circle making a large odd looking shape. It all subtracted fine.

Subtract 02.afdesign

 

[finitystone]

That's also working for me @Old Bruce!

I'm happy actually with both solutions, but it makes me curious why that happens. Try to figure out the orientation/fill behavior.

 

[Old Bruce]

2 minutes ago, finitystone said:

I'm happy actually with both solutions, but it makes me curious why that happens. 

You and I and so many other people.

[Old Bruce]

1 minute ago, BofG said:

If you scale both objects up to a massive size (so the thin rectangle is a few hundred px tall), does it then work? Not at a computer to check.

I tried that and no it didn't. I didn't scale it to more than 500% so I can't say for certain.

[JimmyJack]

Hi @finitystone

Step 1: Alt/option Boolean Subtract (to create a compound subtraction)

Step 2: CMD Return (convert to curves)

Step 3: Don't ask why 🙃

[R C-R]

2 hours ago, Old Bruce said:

I tried that and no it didn't. I didn't scale it to more than 500% so I can't say for certain.

I scaled up to 20 times larger & to 30 times larger -- it still did not work.