[mathking]

We tried to make a screw lift in 2006 and it didn't work out for us. I kind of hope we can at least get a good prototype this year because I think they look really cool.

In our final 2006 design, we used a conveyor belt from flat conveyor material that was very effective. We used pvc pipe (with many "speed holes") with end caps for the rollers. We could pick up balls really well with it, and fairly easily get two balls side by side. (Unfortunately the shooting was not so good...) That said, a preliminary hand powered prototype vertical conveyor with four strands of surgical tubing worked pretty well lifting the orbit balls up 3 feet last night. One key is having a good surface opposite the conveyor to help maintain the force on the balls. The conveyor worked well enough that the render of the robot with the conveyor is still hanging on my classroom wall.

Another thing to watch out for the conveyor mangling the balls if they stay and and get pulled back down. In 2006 we would occasionally pull the balls through a 2 cm opening between the conveyor and the chassis if the hopper was full. That would probably destroy the orbit balls.