TR has a 3 wheel holonomic drive using omni wheels. The throwing robot motors, used for the drive are customised to accomodate the particular tasks performed.

Picking Mechanism

The gripper, actuated by a push-pull solenoid, is used to grip the arrows from the arrow rack. The jaws of the gripper are attached to the solenoid using linkages. These grippers are attached to a mild steel shaft which is connected to a Brushed DC motor with worm gearbox, that rotates the shaft along with the gripper and places the arrow on the throwing mechanism. The grippers are 3D printed using PLA material.

Hopper Mechanism

Hopper consists of 3 Aluminium sections. The main function of the hopper is to facilitate the proper transfer of the arrow from the picking mechanism to the Throwing mechanism. It is also used to load the arrows received by receiving mechanism onto the throwing mechanism. A plastic sheet is fixed to one of its ends using L plates to obstruct the arrow if it misses its mark while being released from the picking mechanism. Hopper makes a pathway for the arrow to travel to the throwing mechanism.

Shooting Mechanism

A set of four springs is used to launch the arrow in a projectile motion towards the pot. One end of the springs is fixed while the others are attached to a striker which moves linearly along aluminium rods. Initially, the springs are at rest. The striker is pushed backwards using a pneumatic piston and a linear guide mounted to the frame. The striker is then retained at that position using a locking mechanism. The striker is then released from the locking mechanism. In this way, the arrow placed on the frame is launched towards the pot.


DR has a 3 wheel holonomic drive using omni wheels, constructed using Aluminium sections.

Pick and Pass Mechanism

For the picking mechanism, two arms are attached to the chassis on one of the sides of DR. These arms are controlled and rotated by using a power window motor. The arm consists of a 3D-printed L-shaped plate attached to aluminium sections. For picking the arrow, the L-shaped plates are positioned such that on moving the robot, the L-shaped plates go beneath the body of the arrow .a power window motor is used to rotate the shaft, and hence the arrow is lifted.The Arrow picked up from the ground can either be passed onto the TR using the passing mechanism.

Loading Mechanism

The arrow is rotated using the picking mechanism. When the position of the L plate of the picking mechanism is vertical, the arrow falls off the plate onto the aligned aluminium section. Servo motors are mounted on the sections. The horns of the servo motor are arranged in such a way that the arrow is retained at a certain position. Two such structures are mounted on either side of the throwing mechanism. When the horn of the servo motor is rotated, the arrow rolls down the angular sections, into the throwing mechanism.

Table Pushing and Arrow Interception Mechanism

The primary aim of the table-turning and Arrow deflection mechanism is to turn the table according to the situation i.e. either for misleading the opponent team’s arrows or to position the table for ourselves. The table-turning mechanism consists of 2 aluminium sections mounted at a distance for moving the type II pot table and type III pot table. The ends of these sections are fixed with 3D printed ABS plastic parts meant for making contact with the handles of the Pot Tables. The arrow deflection mechanism consists of a 12V DC Johnson Geared Motor, onto which a latch is coupled. The latch is used to grip and rotate the arrow, thus deflecting the opponent’s arrows and preventing them from landing in the Pots.