OK, we're slowly getting our photo gallery back up and running. Here's a picture of our scissors last year:
http://www.spamrobotics.com/gallery2/nats04/P4150052
We used it to lift the hook to the bar and then used a winch to lift up the robot, so it didn't carry the weight of the robot.
When it worked "as designed" it worked well, most of the time that wasn't the case because it was too flexible out of plane - the problem with most scissors mechanisms. But it was definitely entertaining.