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Ball leaving shooter at Monty Madness
1640's Shooter requirements for Rebound Rumble are:
  • This is a shooter; not a dumper
  • Primarily targeting the top basket
  • High scoring reliability (>67%) from Key or closer
  • Ability to feed balls to alliance scoring field from the outbounder station
  • Backspin to drop into basket and provide dead landing upon feeding
  • Fast recycle; one shot per second (minimum)
  • Automatic rangefinding & aiming
  • Maintain low CoM for bridge balancing & preventing bridge tips

The Shooter system comprises:

  1. A fixed-geometry overshot wheeled shooter
  2. A tachometer to determine and thereby enable control of shooter wheel speed
  3. A camera for aiming
  4. A Drive Mode specifically for aiming the robot
  5. A narrow-beam sonor to determine range to back-board

Key Technical Challenges & Statements

  • A high shooter elevation (trajectory) will be needed to score in the top basket
  • High trajectory shooters shooting from the Key cannot be easily blocked (regardless of shooter height)


  • Wheeled shooter was the only serious concept examined (well, there was some catapult testing early)
  • An overshot wheeled shooter offers the desired backspin
  • To manage mass & cost, it was decided early that a decision to use pivot drive (which was subsequently made) would also become a decision to fix the shooter azimuth relative to the chassis. If we use pivot drive, we will aim the robot; we will not use a turret to aim the shooter.
  • The camera should be utilized to adjust azimuth (relative to field). Automatic aiming preferred if (and only if) this could be demonstrated to result in higher scoring than Driver-aimed/Camera-assisted shooting.
  • A narrow-cone sonar was specified to determine distance to backboard
  • The shooter wheels must be speed-controlled
  • The sonar or alternately the operator to supply the set-point for the shooter wheel speed


Prototyping was limited and the final shooter closely resembled the prototype.

Design Details

Power: Fisher Price -9015 motor with BaneBots P60 4:1 reduction gearbox directly driving a pair of 8" kitbot wheels

3900 unloaded rpm (max)

Shooting Angle: 55° from horizontal (fixed)
Tachometer: Nippon-Denso E6DF motor with custom circuit

Motor Gearbox, shooter wheels and tachometer are all on a common ½" 7075 Al shaft


Issues & Developments