In the summer of 2020 we ran a summer STEM program for junior high and high school students that was originally supposed to be hosted at the Biosphere 2 in Arizona but was obviously cancelled due to COVID. As part of the program we had an Ocean Discovery track where students learned about coral and ROVs. As part of the program we built 10x custom mini-rovs that ended up being tele-operated from all over the world in our school. We had various activities and competitions like picking up dive rings, collecting ping pong balls from the surface, and scanning QR-codes.
Each ROV had 6x “T-eeny-100” thrusters which we made custom by scaling down and modifying a T100 thruster and SLA 3D printing it. We used small drone brushless motors and designed and built all custom electronics including our out embedded flight controller. The computer was a Raspberry Pi4 and our tether was a short length of 5m length of Ethernet cable that ran up to a USB dongle on a custom buoy float. This method helped, but didn’t completely eliminate, tether tangles while flying 10 ROV’s simultaneously in a confined space. The ROVs were powered by an off-the-shelf RC lipo battery pack that could be charged through the tether by connecting a power supply to a barrel plug in the buoy.
We’re currently revising and improving on the design and expect to have the next revision ready for our Ocean Discovery program in the fall.
Here’s a short video of the ROV’s flying around.