Navigating Through the Water with a DIY Remotely Operated Submarine

from hackster.io

Finding out what objects are lying below a local lake or sea can be an extremely fun and exciting adventure, but unfortunately, the equipment required to do this, such as SCUBA gear, is quite expensive. On the other hand, small underwater robots called ROVs (short for remotely operated vehicle) can explore large areas with minimal human involvement. However, they still cost around $3-5k even for entry-level kits, which is why one YouTuber who goes by enso RC decided to make his own for much cheaper.

In order to minimize upfront costs, enso based his design around a preexisting submersible vehicle called the BlueROV2 from Blue Robotics. Their open source plans and wide selection of individual components allowed him to cut out several base plates from sheets of HDPE plastic meant for marine environments using a CNC milling machine and a jigsaw for larger pieces. From here, the central electronics tray was laser cut from acrylic and combined with other 3D-printed parts to form the majority of the ROV.

For propulsion, enso went with a selection of six BRF2838 brushless DC motors that, although not very well insulated from water seepage, are still able to get the job done. Each one was placed within a 3D-printed fairing and had a single propeller installed onto it. After this, the main camera assembly was added to the front along with several electronic speed control (ESC) units for driving the brushless motors. Finally, a Raspberry Pi was included to adjust the motors based on incoming signals from the control software via a tether.

Once the main electronics housing was ensured to be watertight, enso finished the ROV by attaching the thrusters to the chassis, with two facing upwards for buoyancy control and four facing outwards for linear propulsion. The craft's maiden voyage out on the water went fairly well, as the camera and motors worked exactly as intended. The only problem was the discovery of a few leaks around the entry point for the motor wires, which were quickly patched.

The second launch went even better, and enso was able to successfully explore all kinds of areas below the surface, including a dock, a few aquatic plants, and even some sunk golf balls. To read more about this project, you can view its guide here.