I had very good results with PnPAssist V1. However, I saw that there were some opportunities for improvements and started working on the design of V2. The main reason for V1's design change is Center of Mass (CM). The stepper motors are the heaviest part of the system and both motors are positioned at the rear and pulling the CM towards them. However, the CM must be on the main rotary axis, which is in the center. In order to make the CM in the center I decided to place the motors on each side to balance the system. 

The other design change needed is because of the center main gear. This 3D printed part works well, but it is obvious that it will wear out over time due to the large frictional forces on it. This part must be manufactured from metal. However, it will be difficult to manufacture due to its unusual and low tolerance structure. In my new design, I decided to use a timing belt because it was cheap and accessible. With these design considerations here is the design of the V2: