Here is a quick video showing the top speed using 50:1 Spark motors at 11.1V.

Dimensions:
The Cobra conforms to the mini-sumo ruleset of RoboGames, the world's largest robot competition.  Most smaller events uses these rules, but always check with your event organizer to make sure.
Width: 9.9cm (3.90")
Length: 9.75cm (3.84")
Height (ground to top of standoff): 3.77cm (1.48")
Weight: 333grams (11.75oz) - Maximum allowed by RoboGames is 500g (17.63oz)


Kit Includes:

Chassis:	1/16" thick garolite baseplate (pic). Has mounting holes for scoop, standoffs, and 3 QRD1114 floor sensors (2 front, 1 rear).
Motors:	4x 50:1 Gold Spark Gearmotors
Wheels:	4x Cobra mini-sumo wheels.  Shore A20 polyurethane - the highest traction mini-sumo wheels available.
Sensors:	Includes three QRD1114 floor sensors (2 front, 1 rear) mounted to chassis with female headers for easy replacement.
Scoop:	0.020" stainless steel angled scoop (can be legally sharpened to 0.010")
Steel Ballast:	An underweight mini-sumo is at a disadvantage!  This steel ballast keeps the center of gravity low.
Screws:	Four 6-32x0.375" screws for mounting the scoop, ballast and stand-offs.  Four for securing circuit board to standoffs. Two hex wrenches included for tightening screws and setscrews.

Requires:

Battery:	The chassis has a spot to accomodate a 26x53x26mm (2x1x1") battery.  Our Rhino 11.1V 360mAh fits perfectly and will run the robot for dozens of matches.  Some Velcro will secure it in place.
Electronics:	In the chassis kit, the brains are up to you.  Boards from the SumoVore, Mark III, SumoBot or even an Arduino all work!  Use the PCB Mount Kit to fit board with different hole patterns.
Sensors:	Opponent detection can be anything you desire.  Infrared emitters/sensors are most commong, but ultrasonic sensors are an option too.
Motor drivers:	If your "brain" does not include motor drivers, two tinyESCs can be used (1 per side).  They are very small and can be controlled using simple Servo PWM - only one data line each is required!

Orders normally ship within 1-2 days.  Other motor ratios can be used - please add a note in the checkout comments. (35:1 is the most commonly used after the default 50:1, but make sure your sensors can react fast enough to the increased speed!)