Hi I need some help making rocks circle around a sword like a planet’s gravitational pull or like the planets orbit 
Can you show a pic of what you want?
you need to define a central axis along the blade. I would suggest adding an empty, positioning it in the center of the blade, and parenting it to the sword object. then add the rocks, and parent them to the empty. now set a keyframe for rotation ( for the empty ). go ahead a few frames, and hit N to get your numerical input. you will need to change the value of the x y or z rotation, depending on the orientation of your scene. when you determine the correct axis, change it’s value somewhat, so it has rotated a bit. now set another keyframe. now…go into the graph editor, and you will see your keyframes, all selected. hit T and choose the option ‘linear’. then, from one of the pullup menus ( I will get back to you on which ) change the ‘extend mode’ to 'extrapolation. now your rocks will orbit the sword at a constant rate, and continue to do so for as long as it takes.
I’m pretty clumsy to what concerns animations however there’s how you create circle of rocks and some lightning fiery using minimal effort:
http://www.pasteall.org/blend/36145
http://sendvid.com/xhbwnv52
thx guys for the help
If you have any problems, just post the blend file and I’ll set it up for you.
The lightning renders in frames 8-10 (yup, only during 3 frames).
your hemi lamp has keyframes attached to it. that is likely the issue. try deleting the f-curve and resetting the value of your hemi lamp.
Ok, this is how and why. Material for lightning has a Transparent shader which makes mesh invisible. Blend Sphere texture is set to drive Mix of Emit or Transparent. Depending where this “invisible” sphere is you see either nothing or lightning mesh which emits light. Mapping node tells where mask sphere is at given frame so that if you wanted lightning to shine longer you’d need to play with Mapping node’s values and keyframe these as you like.
Here’s a file where you can see this sphere “in action” more clearly. http://www.pasteall.org/blend/36192
Switch one window to rendered view and play animation.