2006-2007

Game Description – Rack ‘n’ Roll

Rack ‘n’ Roll is played by two three-team alliances on a large field with a center structure (Rack) containing 24 “spider legs.” To score, teams use three different types of tubes called “Keepers,” “Ringers,” and “Spoilers.” The game is made up of two scoring periods. In autonomous mode, which lasts 15 seconds, robots try to place a Keeper on one of the spider legs of the Rack using a vision tracking system to locate one of the four target lights at the top of the rack. Once placed, a Keeper tube may not be removed or “Spoiled.” During the operator control period (2 minutes), the teams attempt to score points by adding “Ringers” onto the spider legs or by “Spoiling” the opposing teams score by placing a black tube over a “Ringer.” Points are earned and scored exponentially by the number of consecutive Ringers and Keepers in a column or row. Alliances may score additional points if their robots are in their home zone and have been lifted off the floor 4″ or more (15 points each) or 12″ or more (30 points each) by another robot before the end of the match.

Robot Description

D-Fence v2.0

The robot was designed to raise two robots to 14 inches above the ground with the option to add a suction cup to pick up the tubes. The ramps to lift the robot folded down on from the sides making the robot over 10 feet wide. In order to rotate platforms properly the chassis was designed with 20 sides. The outside of the chassis weaved in an out of the six wheels allowing the maximum wheel base but also let the platforms rotate where the chain normally would be. The platforms started off at slightly over 4″ to guarentee some points if the raising didn’t work. The platforms were raised by a pneumatic piston in the center of the robot through a wire cable pulling a four bar linkage.

• Driveline Concept – 4 wheel version
• Driveline Concept – 4 wheel version
• Driveline – side view, 6 wheels
• Lifting Concept
• Suction Cup Drawing

D-Fence v2.1

When we arrived at Boston it was found out that the robot was 5 pounds over. The easiest way to shave two pounds off the robot was to either remove a CIM motor from each side of the driveline or remove the fence completely. It was determined that the best route to take was to remove the CIM motors since the fence was something the team so deeply sypathized with.

D-Fence v2.2

After the Boston Regional the center wheels were sagging to the point all six wheels were touching the ground at once. To fix this the wheel wells were redesigned and moved the rotation of the platforms from between the wheels to the outside. This allowed a solid peice of aluminum to go down the entire side strengthening the entire robot.

D-Fence v2.3

The initial plan to raise robots to 12″ didn’t work out as planned and the pneumatic cylinder wasn’t strong enough to raise a robot. A solution to this was to take the two cylinders on the same platform and not lift the other. At the same time the platforms were strengthened so that the weight of the robots on them would not make them bow as much.

Competitions Attended

• Savage Soccer
• Boston Regional
• Mayhem in Merrimack
• BattleCry@WPI
• RiverRage

Awards Won

• Judge’s Award – Savage Soccer

Match Results

Boston Regional

Battlecry@WPI

Boston