Analyzing a fixture - FBD help

[Triathlete]

Homework Statement

I am designing a fixture to hold a large piece of sheet metal on which a track robot will be tested vertically. Below is a sketch (the sheet metal on which the track and robot will be mounted will be attached to the vertical aluminum extrusions in the back)
The weight of the robot, track, and sheet metal will be around 200lbs.
I need to do a structural analysis to determine if this will be structurally sound or if I need to add extra supports or counterweight.

https://drive.google.com/file/d/0B0tZHukk_GenaHdmaXFwMFZNOVE/view?usp=sharing

side view
https://drive.google.com/file/d/0B0tZHukk_GenRWdfWlhfeWhPLVE/view?usp=sharing

Homework Equations

I am in need of assistance with the free body diagram, I know where to go from there so no equations are needed at the moment.

The Attempt at a Solution

I am not sure where to start here in terms of the FBD, especially in regards to the weight of the robot and sheet metal and where those forces would lie.

 

[Nidum]

If you want help with this problem then please post some proper engineering drawings of the assembly with backplate , rails and robot in place .