From Team 449 Wiki
One feature of Totedile were the two pair of gripping arms. Each pair of arms was actuated by running a single cylinder between them. Since the purpose of a cylinder is to change length, the arms were bounded between hard stops. When the cylinder was extended, both arms would be pushed to the outer hard stops. When retracted, both arms would be pulled to the inner hard stops.
When not moving, the elevator was held in place by air brakes. Each corner of the elevator (4 in total) had a small pancake cylinder with a brake pad attached to the end. The brake pad consisted of a piece of rubber tread backed by a metal plate. When the cylinders were extended, the elevator carriage was prevented from falling by the friction between the brake pads and the elevator rails.
The main mechanism was an elevator. It consisted of a set of arms on a carriage, which used 80/20 wheels to roll up and down along 80/20 rails. The carriage was driven by two CIMs, which were connected to the carriage by two long chains running around sprockets on the CIMs and at the top. This was a bad idea, as the chains constantly stretched and required frequent tensioning. Chains are not designed to be this long, and long enough belts exist and are strong enough, so we should have used those.
The drive was a 4-CIM, 6-wheel tank drive using WCP gearboxes. It had Colson wheels in the center and paired Omni wheels at the front and back. This allowed for easy pivot turning. However, a better decision would have been to use Meccanum wheels, as one major problem was aligning laterally with the feeder station. We didn't use Meccanum wheels because there was a concern that they would not be able to drive over the scoring platforms, but this turned out to be unfounded.