BRR - Better Render Results
I might be at the right way.
After som great tips from people, the slingshot finlay seams to fit in the picture.
Thers a few thing that could be better.
Tell me what you think I shall se what I can do.
Also I have removed the white templates at the base of the slingshot, and the track marks ate the walls.
What remains is the stative I leand on.