Smartphone clamp for tripod

This thing has been upgraded!! See https://www.thingiverse.com/thing:2841720

A clamp to grip your smartphone and mount it to your tripod.

You'll need a 3" section of 8-32 threaded rod and mating wingnut.

A spring - http://www.springsfast.com/part_detail_compression.php?part=231&PHPSESSID=429e7b957e167b25bce45040d41c1fb7

And a 1/4-20 nut

5-minute epoxy

Optional:
Line the jaws with a thin layer of Sugru for a softer and stickier grip