Buzz15 - Ramp Cresting Articulating Chassis System Industrial Design Award Winner 2010 FIRST World Championship FRC Team #33 Killer Bees Jim Zondag

Floor Configuration: Lift arm holds center wheel set in drop center position. 1/8” of center wheel drop enables nimble flat floor maneuverability with the traction of a full 6 x 6 drive train. Spring loaded ball collector Floats on rollers along the floor This unique design centers around two key design elements: 1.A pivoting 4WD 2-Speed Chassis Module. 2.A dual function lift arm which controls the position of the chassis module, as well as being able to lift the robot off the floor for the endgame bonus.

Complete Chassis System is a hybrid design: Welded Box Tube inner structural frame with additional sheet metal bridge components Motive power for front wheels is routed through 4 sets of idler sprockets

Chassis Module: Self-contained 4WD unit. Riveted Sheet metal Construction. Houses core electronics. AM GEN1 2 speed Transmissions. Full width rear axle tube is the main pivot for the Chassis system.

Approach: Arm lifts slightly to allow center wheel set to float relative to vehicle body: Chassis module can now rotate about rear axle

Ascent: Ball collector presses into the front of machine. Chassis Module Drops as front wheels lift to maintain contact with floor through the dip. Floating Hood Panel moves Up and down with Chassis Module

Climbing: Center wheel set can retract up to 4.5” into the vehicle body. Maximum body tilt angle is only 28 degrees. Only 2.5” of true “climbing” are required before center wheels are on The top surface of the ramp

Cresting: Robot moves easily and stably across the upper ramp surface. Retracted center wheel allows Center of Gravity to remain close to ground surfaces. Wheels never break contact by more than 1.5” at any time during traversing maneuver. 4 driven wheels remain in contact with the surface at all times. Ball collector drops down to prevent balls from Going under machine on descent.

Descent: Once the Center of Gravity is over the crest, the robot will descent smoothly with all 6 wheels controlling the descent. 28 degree descent angle minimizes impact to front wheels and axles.

Exit: Chassis Module drops back down as robot descends Back to arena floor. Ball collector maintains zero clearance to floor through entire descent. Lift Arm drops as Chassis Module comes Down.

Resume Scoring: Lift Arm locks Chassis back into flat floor stance. 1/8” drop center posture is restored.

End Game Configuration: Lift arm deploys 180 degrees in 1.5 seconds

Modular Lift Arm Design Combined NBD/Toughbox reducer Total of 805:1 gear reduction in 1 st Gear Over 450 ft.lbs of max Torque output Lifts robot to 24” in 4 seconds Servo shifter for fast deployment. “Antennae” help driver to quickly line up with pole Easy locking Gate latch Design Friction pad keeps robot from slipping down pipe

12” reach out allow robot to easily grab pipe with Offset approach angles of over 60 degrees.

End Game Two Point Bonus: Robot rotates 120 Degrees about shoulder axis in 4 seconds to earn bonus points. Bottom of Chassis Module makes an excellent location for signage