C-Clamp (G-Clamp)

This C-Clamp is a useful tool for every application when you need to keep something temporarily in place or apply pressure while glue dries out.

Max jaw span: 210 mm
Max depth: 95 mm

You can print frame and screw in one piece, but they are 310 mm and 320 mm respectively. So I've prepared two-piece versions of both. 
As for the frame, FEA simulation says it's the point of minimum stress, yet remember to apply a thick layer of adhesive on each surface (up to the root diameter in case of the screw).

Similarly, it may be needed to glue the handle to the screw.

The cap and end of the screw fit in such a way, that there is minimum contact (minimum friction). It allows the screw to rotate freely and to avoid scratching the surface by unwanted rotational movement of the cap.
To prevent the cap from falling out there are three slots for M3 nuts in which you can then screw M3 bolts.

For easier tightening handle can rotate 90 degrees to each side.