These beam couplings are really good for coupling rotational sensors with drive shafts so that small misalignments won't damage the sensor. we use them in our swerve drives to couple the Magnepot Hall Effect Potentiometer which provides us with drive angle measurements for each of our wheels. These couplings are absolutely wonderful and work flawlessly in this application. A photo of the installed coupling is provided:
http://wiki.team1640.com/index.php?t...0209_csm-2.jpg
On the other hand, they won't hold up to very high torque (use Lovejoy couplings for this), massive misalignments or huge angular displacements (use flex joints here). They also cannot be used as the device which keeps everything aligned by itself.
The movie was entertaining, though.