UPDATED 7/2018 Added V2 mount arm for a different camera orientation.
This new piece requires supports from bed only.
The printed version shown above is my prototype, it works for me so I didn't reprint, but I did make a few changes to correct mounting screw hole sizes for more secure mounting.
In addition to your print you will need:
2 X M3 30mm
1 X M3 20mm
2 X M3 wingnut or standard nut
2 X M5 10mm
2 X M5 T-Nut
2 X M3 washers