[Eirik] wrote in to share the build log for the third iteration of his underwater ROV. The first two project were completed and tested (you may remember reading about it back in January), but both had issues that caused general failure. Most notably, the introduction of water where he didn’t want it. But this time around he seems to have gotten everything right, successfully taking this little guy down to twenty meters without a leak.
One of the problems he had on version two was supplying electricity from the surface. He needs 12V at up to 10A, and had to use a tether made of 14 AWG to make it happen. That’s a lot of heavy wire to be hauling around and it made the ROV virtually unable to move itself. He wanted to go back to using Cat5e cable but it won’t handle that kind of current. He ended up using an inverter at the surface to up the voltage to 130V, and a switch mode supply on the ROV to get back to 12V. This caused noise on the data lines which he fixed by adding a full-wave rectifer to the inverter’s output.
The dive video after the break shows off the crystal-clear camera shots this thing can capture.
Continue reading “High voltage ROV adventures”
[Byrel Mitchell] wrote in to share some details on this water glider which he has been working on with his classmates at the Nonlinear Autonomous Systems lab of Michigan Technological University. As its name implies, it glides through the water rather than using propulsion systems typically found on underwater ROVs. The wings on either side of the body are fixed in place, converting changes in ballast to forward momentum.
The front of the glider is at the bottom right of the image above. Look closely and you’ll see a trio of syringes pointed toward the nose. These act as the ballast tanks. A gear motor moves a pinion connected to the syringe plungers, allowing the Arduino which drives the device to fill and empty the tanks with water. When full the nose sinks and the glider moves forward, when empty it rises to the surface which also results in forward movement.
After the break you can find two videos The first shows off the functionality and demonstrates the device in a swimming pool. The second covers the details of the control systems.
Continue reading “Water glider prototype”
[Eirik] wants to help inspire others to take on big projects to he sent in a link to his ROV project. He started it about one year ago and the image above shows the first generation. After the break you can see the video that the ROV captured during a couple of it’s initial voyages. They’re pretty clear and right off the bat you’ll see the little guy following a jellyfish. Like a lot of homebrew ROV’s [Eirik] is still searching for the right way to pass wires through the housing without leaks. He does okay so far, and has designed a nice cable spool for the topside tether, but some water does get in. He’s almost finished the second generation which re-designs the camera mount to aim downward so that what’s in frame is more interesting.
Continue reading “Two generations of ocean-going ROV”
Next time you head off on that underwater adventure take your camera along with you. [Jkcobabe] shows us how to build a waterproof camera enclosure using just a few components. The box is meant to be used to keep your stuff dry while camping, and the lens housing is made using plumbing fittings from the a home building center. There is a rail system that allows you to mount the camera securely inside, with a flexible button on the outside to actuate the shutter. If anything this is well designed and built, but we might still stick to using disposable cameras under water. Then again, the pros build their own enclosures so we’ll keep our fingers crossed for that $2500 camera as you try to capture that perfect shot.
PVC hull, SLA batteries, Bilge Pumps, sounds like a good start to [Jimmy’s] ROV project. Paintball gun (as a BCD), dual live cameras paired with an Arduino making it internet controlled, all tethered with a fiber optic cable, sounds like [Jimmy’s] ROV got a whole lot more astounding.
While some very important parts have yet to be implemented, like the leak detectors, the project looks to be going quite smoothly. With updates promised, we can’t wait to watch this continue until the end.
Related: Yellow Subs and double ROVs
This fantastically huge housing was put together by [Ed Sauer]. He put it together using TIG welded 6061 aluminum for the body and machined the port mount out of 7075 aluminum. The lens port is a commercial unit from a housing manufacturer along with a few manual controls. He wrote up the build in this pdf.
Underwater camera housings work great – but they are prone to humidity, dirt and dust problems if you open them more often than needed. In order to download the images off of his digital camera between dives, [Matt] decided to add a waterproof external USB port to his housing. He had an extra 5 pin strobe bulkhead installed by Ikelite (makers of excellent housings). Then he spliced on a mini-usb cable for the camera and spliced a standard USB end onto a strobe cable. During dives, the port is closed with an o-ring sealed cap.