Why Isn't Mirror Tool Working Correctly? I am trying to follow this video, https://www.youtube.com/watch?v=QbSmoZCrP8I and make the tower the way he does. At about the 5:30 minute point he turns the circle and deletes 3/4 of it. When I try to mirror it like he does some of the edges are missing and don't make a complete circle. I tried it with a plane instead of a circle and I can make it work. Why would the mirror function leave out some edges?

Here is a image of what is happening. The left side is what I am trying to mirror.



Yes, I know he uses the Mirror modifier on both axes, X and Y. I left Y out of this image to show how it's not mirroring even one axes correctly. Here is a screen shot with both X and Y axes.



LeoNas, thank you, that worked. We can call this one solved.
I figured it out.

After you rotate and delete some vertices, you must apply the rotation.

Object>>Apply>>Rotation.
Ctrl + A, then R.