Update 20/1/19: I have added a version without the hinge as mine broke after about a month or two, probably as it had to be printed in a certain orientation for the hinge, the non hinge version should be printed in the orientation shown.

It is held up by the screw on the other side, has a hinge so it can be folded away.

The hinge idea taken from here.

Using the amazingly simple but genius hinge design by mathgrrl.

Yes

0.3

20%, I tested the hinge with 40 and 50 but it kept getting stuck so I went with 20, seems strong enough