Hammock Phone Hanger [Old version, check description for new one]

[V3 available now on MakerWorld: https://makerworld.com/en/models/1521236-phone-holder-for-hammocks-tents-rope-lines It's now even smaller and all tolerance issues are fixed]

New version now available. Smaller, lighter, more angles: https://www.printables.com/model/582669-hammock-phone-holder-v2

Hammock Phone Holder  

Like hammock camping but hate holding your own phone? This is the fully 3D printed solution to your problems. It's adjustable to fit different phone sizes, and uses a lockable ball joint to give you a variety of viewing angles.  

Fits into place easily over ropes and lines up to 8mm diameter, without having to undo any ropes, and can be tensioned with optional screws to grip the rope, allowing you to mount it on angled or even vertical lines.

Works with phones up to ~96mm width.

Easily adjustable viewing angle, simply loosen the ball joint nut, reposition and lock into place.

Fully 3D printable, no screws, nuts, glues, required.

Assembly:
Print one of each main piece, and two of the screws, although they're optional. 
Carefully cut off the arm cup's built-in adhesion bars to prevent warping during printing.
Place the threaded end of the ball through the ball nut, then tighten the ball into the hanger.
Slide the arm fully into the arm cup. 
Slide bottom notch onto arm, with notch facing the top.
Screw arm nut onto hanger. 
Optionally, screw in hanger screws to grip onto rope.