The 10th robot built by the team was able to pick up totes / recycling cans and place them on top of each other. It did this using an elevator system where the robot would pick up the bottom item then drive over to the next tote and place the stack on it. To bring the totes into the robot two wheels were attached to arms that would pull in the totes.
After a couple of matches the arms to pull in the totes were shortened.
Eventually the arms were removed all together.