Rotating a half-circle perfectly

I’ve been trying out Blender for a while, and have now come upon this problem:

I started with a full circle, and then extruded it upwards (to create a base for a lantern).
I then decided to remove one side of it to use the mirror modifier, but the half that was left was not rotated in the right way (see image).

Is there a way to perfectly align the ends with the grid?


Let the pivot be in the center of the cicle and remove half part of the circle. Then try to rotate. It will do. You image is shwoing that u r going right way.

Thanks for answering

I rotated it, added a mirror modifier, but got this:

Do you know what’s causing this problem?


Uploading help3.blend
Open this file and press ALT+A
If you want again help then pm me.


help3.blend (120 KB)

1-st option. Find the angle to which you want to rotate. Create a triangle face and use Edge Angles button to see its angle values. Thus you will no how much you have to input for the angle when rotating the torus. (slow)

2-nd option. Use Snap tool with reference object. Create an edge with two vertices pointing straight up. Snap the torus to the bottom vertex, place the 3D cursor there. Select the torus and rotate it with 3D cursor as rotating pivot, snapping at the upper vertex.(fast)

3-rd option. Start from scratch. Create a Torus with Major Segments=14 (the rest of the settings are up to you), rotate the torus 12.5 degrees, delete the half.(mediate)

The mirror being off is caused because you seem to have rotated the half circle in object mode. It has a RotZ attached, as you can see in the transform properties. If you had rotated in edit mode, RotZ would still be zero.

To fix this now just apply the rotation with CTRL-A (first option). You will notice that after that the RotZ will be zero again and the mirror should be correct then.


You really helped me,

You’re welcome.

And welcome to the forums (hadn’t realized your post count)! :slight_smile: