Problem with Bevel modifier I just started to learn Blender and met a problem when using Bevel modifier when creating a cogwheel. Most edges where processed fine, but a few of them got errors:





I have checked all the normals, they are correct. Here is the model without the modifier:



It seems ok, but I worry about black color of the edge exactly where the bevel makes mistakes
Thanks to hint from 4-K, I indeed found out that the problem was because of duplicates. To check it, I just moved single vertices in edit mode.

To remove them I did the following:


Open the edit mode for vertices.
Select all the vertices using A key.
Open special menu using W key.
Click "Remove Doubles".


Then Blender said that there were 8 redundant vertices, and I got correctly working bevel modifier.