problem with spin 360

Hi
I’ve got a problem with spin (360)
when I use a spin on the object, the line appears
do not even know what to do
I’ll add that I am a beginner in 3D

some screenshots:
http://imageshack.us/g/856/obrazek1e.png/

Select all your vertices (A) and the W / remove doubles. You have a duplicate set of vertices overlapping the original points your spun. This will delete these duplicates.

yeah
it works
Thank you