• Development of the new Cobra kit is taking longer than projected, so in the meantime you can purchase this package that includes the best parts of the Cobra R5.
• Designed to be a competitive entry into the masters class of mini-sumo, this chassis has the ability to beat those big-wheeled servo bots every single time.
• Includes 4WD Gold Spark motors, four high-traction mini-sumo wheels, stainless steel scoop, heavy steel ballast, screws, wrenches, stand-offs, and the pcb-mounting kit for attaching your control board.
• Does NOT include: control board, motor controllers, line or opponent sensors, battery. Requires gluing motors to metal plate.
• If you would still like to be informed when the new Cobra kit is available, sign up for email notification on the original Cobra product.
Dimensions (of Cobra R5 - this kit does not include the 0.0625" thick red pcb):
The Cobra conforms to the standard mini-sumo ruleset. Most events uses these dimensions, 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 in competition is 500g (17.63oz)
||Four 50:1 Gold Spark Gearmotors to be glued in place as shown above.
||Four FingerTech Mini-Sumo Wheels. Shore A20 polyurethane - the highest traction mini-sumo wheels available.
||0.020" stainless steel angled scoop (can be legally sharpened to 0.010" per RoboGames rules)
||An underweight mini-sumo is at a disadvantage! This steel ballast keeps the center of gravity low.
||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. Also includes PCB Mounting Kit.
||The chassis has a spot to accomodate a 44x24x29mm (1.75x0.93x1.15") battery. Our Nanotech 7.4V 300mAh or Nanotech 11.1V 180mAh fit perfectly and will run the robot for several matches. Min/Max Voltage: 6V-16V.
||The Cobra requires two motor drivers (left and right, with two motors on each side wired in parallel). If your control board does not include motor drivers, you can use two tinyESCs which operate from a servo signal.
||In the Cobra chassis kit, the brains are up to you. We carry the user-friendly Arduino Uno's, but boards from the SumoVore, Mark III, or SumoBot will all work. The included PCB Mount Kit will fit boards with different hole patterns.
||Opponent detection can be anything you desire. Infrared emitters/sensors are most common, but ultrasonic sensors are an option too.
Common line sensors include the QTR reflectivity sensors carried by Pololu Robotics.
Orders normally ship within 1-2 days. Other Gold Spark motor ratios
can be used for an additional $10 fee - please add a note in the Additional Comments section of checkout for which ratio you would like. (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!)