Hi, I would like to put a lip and groove feature pair on two halves of a handle. 

I used the handle model from Entry #3 by Lin Shao Dun http://www.dezignstuff.com/blog/?p=1909

I trimmed the top of the surface model to flatten it, filled in the top, then knit to make it a closed surface.  I then solidified using the thicken command and split the handle down the middle into two separate parts.  To hollow out the handle halves, I used Shell.

I am having trouble getting the lip / groove feature to work at all. I've tried using both the interior and exterior edges, but haven't had much success. 

After I accomplish this, I'd like to put mounting bosses on one/both of the halves so that they can be screwed together.  Additionally, the part should have "brackets" to hold a 9V battery within and keep it from rattling around.

This handle is supposed to clamp onto an LED-lit camera calibration rod, so there will be a hole at the end of the handle to accomodate this.

Thanks for your help,

Alex