A very basic shoulder rig for a camera.
Feel free to design attachments (e.g. follow-focus, handle, connectors for microphones, lights, display, barn doors or recording-devices) and improvements (e.g. an offset rig for DSLRs lacking a turnable display, different shoulder-supports, 3/4" parts instead of 1/4",...)
When the rig is finished, I'll provide exports of all parts into a number of CAD-formats to make it easy to reuse and improve them.
IF YOU HAVE NO ACCESS TO A 3D-PRINTER AND CAN't FINE SOMEONE ELSE TO PRINT THESE FOR YOU, YOU CAN HAVE SHAPEWAYS PRINT THESE FOR YOU:
1: remove both nuts from the Seagull's 1/4" bolt. See the photos if unsure.
2: print 1x MiddlePiece, 2x MiddlePiece_Seagull2, 1x MiddlePiece_Seagull and the camera_plate.
3: attach the quick-release adapter to the camera_plate
4: attach the MiddlePiece_Seagull* to the rods, 2 Seagull2 framing one Seagull
5: attach the camera_plate to the MiddlePieces. Use all bolts. They are needed so the rig does not flex
6: attach the rig to the Seagull using the long 1/4 nut. Go through the center MiddlePiece_Seagull2 and through camera_plate into the quick-release adapter
7: try on the rig and mark a comfortable length for the rods
8: NOW cut the rods to the required length for your body and camera-equipment.
9: print the T-connectors and connect the shorter rods
10: print the 2x EndPiece, try them on, mark the holes on the rods
11: Attach the remaining MiddlePiece behind the arc of the Seagull shoulder-pad
12: drill into the rods and fasten the EndPiece on both ends this way.