Static equilibrium, machines; handheld press

[J-dizzal]

Homework Statement

The handheld press is useful for such tasks as squeezing rivets or punching holes. What force P is applied to the sheet metal at E for the 64-N forces applied to the handles?

Homework Equations

The Attempt at a Solution

Not sure how to get this one started, i initially took the moment of the top piece but that didnt solve for anything.

 

[paisiello2]

I think you made a very good start with the first free body diagram. I think the key is to realize that the cylinder DE (shown as hidden lines) is free to move vertically independently.

 

[haruspex]

Think about mechanical advantage and movement ratios.
If the lever is moved down a small distance dx, by how much does the angle change?
If the angle changes by a small amount $d\theta$, how far does D move down?
(Draw yourself a larger diagram of the C/D region).