The objective of the MADWEC 4.0 mechanical team was to optimize and redesign the PTO system, which utilizes the oscillatory motion of the waves and a reel system to spin a shaft that drives a generator to create power output. The previous year’s PTO system had a low power output and efficiency, so the team needed to update the system to increase power output and optimize efficiency by characterizing the losses in the system and separating mechanical and electrical losses. To achieve this, the entire system was redesigned into a bench-top test setup utilizing a rail system. Each component was coupled together with shaft couplings to create subassemblies that can be easily removed or shifted along the rails to allow for the implementation of new components. The system is now modular, and sensors, including a reaction torque sensor, a rotary encoder, a load cell, and multiple current sensors, were implemented throughout the system to characterize mechanical and electrical losses. The final major change to the system was the use of a single low RPM generator instead of six small high RPM generators. This allowed the system to reach the nominal RPM of the generator, ultimately increasing power output.