The first step in our actual robot is to find a concept. We were instructed to build a robot that could play Jenga against other robots. Although the robot can make use of as many degrees of freedom as they wish, but only one of these degrees of freedom may be a linear axis. The other degrees of freedom are to be designed as rotary axes. In order to achieve this, we considered a construction similar to a robot arm on wheels, for which the shoulder and the elbow depend on each other, and the gripper can move independently. We use 2 steppers in order to move the shoulder and the elbow. C-belts and gears are used to transfer the power of the motors. We had estimated that the shoulder of the robot arm has to lift about a half kilogram, thus we calculated that we need a couple of 0,24 Nm and therefore required a reduction of 35 on the gears to lift it. In order to move the gripper in the vertical direction, we used a servo, and to open it and pinch it, a servo is also used. Wheels were used to make the robot move forward and backwards. The two back wheels were driven by a DC motor on one axis.

Our Jenga-robot was able to reach the bottom and the top of any Jenga-tower. Even if our robot could do these acts, there were still many problems that had to be solved. The management of the cables was disastrous. We were not using any connector and every connection consisted of a single cable, which was connected from pin to pin, making the structure of the electronic circuits very confusing.  The disposition of the two stepper-motors wasn't optimal either. We needed a perfect symmetry in the robot's structure to provide an equilibrated tension between the two C-belts used for the lower axis. An adequate place for those two stepper-motors had to be found. The usage of C-belts required a great amount of tension. However, the tractive force of the C-belts caused a flexion in the bottom plate. According to the bending formula, a three millimetre thick MDF-plate wouldn't be the best way to compensate this force.

Besides these problems, a new robot hand had to be designed and tested. The challenges at that moment were to solve these problems, while working on an unchanged design. To achieve a good robot, the inverse kinematics of two axis had to be solved and implemented in the Arduino.

First of all, we started with the build of a controller so that all the cables would be managed at the same place. The controller's box had the same dimensions as the bottom plate of the robot and consisted of two floors. All the SOC's[1] used for the stepper-motors were fixed on the first floor, the SOC's for the DC-motors and the two Arduino’s on the second. Finally, two electrodes were implemented into the system. These electrodes were used as 12V power inputs, providing the required amount of energy.

A way of symmetrically implementing our two stepper-motors was eventually discovered. We shortened the gear-support. This created more place to put and fix the two stepper-motors side by side. The force balance between the two C-belts became restored. To prevent the bottom plane from bending, we implemented two six millimetre MDF-plates perpendicular under it.  In terms of DC-motors, they stayed unchanged.

For the final version of the robot, we switched from a system of three Arduino’s to a system of only two. The first Arduino was used to control the two stepper-motors simultaneously. The second Arduino was used to control the two DC-motors and the two servo-motors. With some calculations, the inverse kinematics were solved and implemented in the Arduino's.  Eventually, we totally redesigned the robot hand. The final version consisted of two servo-motors: the first one controlled the inclination, the second one controlled the opening of the hand. Two mouthpieces were placed at the end of the robot hand. The reason why these mouthpieces were implemented was to have a better grip on the Jenga blocks.