The robot lifter here was probably the fourth lifter robot we built. We designed it as an example for one of the annual Robotic Society of America (http://www.robots.org/ ) competitions, but we didn't actually enter the competition since we were a sponsor.

In this demo, we use a different type of ribbon (surveyor's tape) and only climbed about 7 feet, though at a much faster climb speed than previous versions. This design (approximately 11 in. x 4-5 in. x 2 in.) was not as "blocky" as the previous design and thus did not suffer the same awkward center of mass changes as before. We also made some improvements to the guide system.

Although it was built with a LEGO body, this is the first time we designed our own robot "brains" (both the hardware and the code) instead of using the LEGO Mindstorms system (http://mindstorms.lego.com/ ). This is also one of the first designs to start having truly robotic features such as sensors to detect when the lifter is at the top or bottom of the ribbon. In the video you can see an example of this when the top sensor contacts the top "touch plate" (there is also a "touch plate" at the bottom).

The lifter had a braking/locking mechanism. If power was cut while climbing, the robot would stop. However, we have not used the braking system since then.

Finally, this was the first lifter to have a passenger: a LEGO figure named "A. B. Clark". (less info)