I lost the plate for my tripod, that holds the screw for the camera. So I made another one.
Even if you don't loose it, it's always nice to have multiple plates, one for each camera !
I used these screws : http://www.ebay.com/itm/141737493634

You can easily adjust the OpenSCAD file for other screws. You may have to adjust some dimensions, everything is a tight fit and it's linked to your printer calibration.

There is no lock washer, the screw is force-fitted in place so it doesn't fall unless you unscrew it yourself (however the OpenSCAD file has provisions for a lock washer if you can/want to print with support).

There is a self-centering bevel on the back so that when you screw the screw into the camera, the screw should self center. Use a 0.1mm print height so that the self-centering bevel is as smooth as possible.

I do not have the model number for my tripod, so I attached a picture.
It's very likely that you can adjust the OpenSCAD model for other tripods too. If you do so, make sure to upload a remix ! :)

Code is not the cleanest - but it does the job.

There is also a nice roundedCube module for rounded edge cubes. It compensates for the additional size added by the Minkowski transform used, something I rarely see. Pretty handy.

I also designed replacement feet for the same tripod :
http://www.thingiverse.com/thing:1284763

RepRap

Sunhokey Prusa i3

No

Doesn't Matter

0.1mm

30% minimum

Print upside-down so that the surface in contact with the camera body is on the print bed.
Printed with MG Chemicals white PLA, 215 degC extrusion, 45 degC bed, on green painter's tape, with Elmer's purple school glue stick put on tape for improved adhesion.
Use 0.8mm or higher perimeter and top/bottom thickness