As the caption says: There is no rotational movement in this picture. They are all travelling linearly.
In the comments there are different versions linked that could also make boot animations, but I made the main one an animation.
The size is 800x800 which I think looks good on the Nexus 5. Can't say the same for other devices.
COPY TO /system/media/bootanimation.zip - Don't try and flash it!
Edit: the preview on the Nexus 5 looks odd. Best viewed on PC