Stingray ROV
Posted: Oct 23rd, 2022, 4:29 pm
Hi All,
I have only really posted about my thruster design so far, so I think I will start a thread about my ROV itself! The end is in sight now, as I have finished all of the thrusters, pressure tested the whole thing in my nearest lake (living in the lake district is handy) and then installed the electronics in the dry tube.
I pressure tested it to just over 30m, which is more than it will see in service since it only has a 25m tether. I may get a longer tether later on if 25m is too short. Unfortunately a small amount of water (only about a teaspoon) leaked into the dry tube, but this was just caused by some epoxy I spilled on one of the sealing faces.
The frame is just made of PVC pipe, so nothing particularly interesting there. All of the buoyancy comes from the dry tube. The thrusters are mounted using 3D-printed clamps, which can be repositioned as required. It has two cheap off-roading lights from e-bay for illumination, which I waterproofed with polyurethane. There is a 90mm diameter (10mm thick) acrylic window bonded to the front of the dry tube. This is flat, not a dome mainly because it was easier this way. It cost about £1 to get it custom cut, which was much less than I expected. I put some metal mesh on the bottom to give me somewhere to put ballast, and also to stop it from sucking in as much debris from the bottom.
The camera is a wide angle raspberry pi camera. I have it pointing slightly downwards to give better visibility directly in front of the ROV (no pan-tilt here unfortunately).
I have tested the ROV in my work's test pool, which went surprisingly well! The first time, one of the thrusters was not running at full speed, but this was just because I forgot to glue the motor shaft to the magnet wheel . The second time everything performed well, and my colleagues had a bit of a competition to pick up a coffee mug off the bottom of the pool! Unfortunately I can't show any pictures or videos of that testing here, because I shouldn't really show images of my workplace without permission.
I have left space and cables for attachments/tools on the T-piece centre front. I have an electromagnet, and might print some other tools such as a grabber. Hopefully I find something other than beer cans to pick up!
The ROV tether plugs into a box topside. This box contains the remains of a router, as well as a battery meter, fuses, switches and a power supply for charging my laptop. The ROV itself is controlled completely from the laptop. The use of Wi-Fi is so that the laptop doesn't have to be directly attached to the tether. This also means that multiple people can connect to the ROV at once and view the live camera feed using their phones.
At the time of writing this post, I am waiting for the ROV's batteries to arrive (so far I have been running it off mains through a step down power supply). As soon as they arrive, I will be able to take it to the lake and do the first open-water test dives. I will try to post some pictures and videos as soon as that happens, hopefully within a week!
I have only really posted about my thruster design so far, so I think I will start a thread about my ROV itself! The end is in sight now, as I have finished all of the thrusters, pressure tested the whole thing in my nearest lake (living in the lake district is handy) and then installed the electronics in the dry tube.
I pressure tested it to just over 30m, which is more than it will see in service since it only has a 25m tether. I may get a longer tether later on if 25m is too short. Unfortunately a small amount of water (only about a teaspoon) leaked into the dry tube, but this was just caused by some epoxy I spilled on one of the sealing faces.
The frame is just made of PVC pipe, so nothing particularly interesting there. All of the buoyancy comes from the dry tube. The thrusters are mounted using 3D-printed clamps, which can be repositioned as required. It has two cheap off-roading lights from e-bay for illumination, which I waterproofed with polyurethane. There is a 90mm diameter (10mm thick) acrylic window bonded to the front of the dry tube. This is flat, not a dome mainly because it was easier this way. It cost about £1 to get it custom cut, which was much less than I expected. I put some metal mesh on the bottom to give me somewhere to put ballast, and also to stop it from sucking in as much debris from the bottom.
The camera is a wide angle raspberry pi camera. I have it pointing slightly downwards to give better visibility directly in front of the ROV (no pan-tilt here unfortunately).
I have tested the ROV in my work's test pool, which went surprisingly well! The first time, one of the thrusters was not running at full speed, but this was just because I forgot to glue the motor shaft to the magnet wheel . The second time everything performed well, and my colleagues had a bit of a competition to pick up a coffee mug off the bottom of the pool! Unfortunately I can't show any pictures or videos of that testing here, because I shouldn't really show images of my workplace without permission.
I have left space and cables for attachments/tools on the T-piece centre front. I have an electromagnet, and might print some other tools such as a grabber. Hopefully I find something other than beer cans to pick up!
The ROV tether plugs into a box topside. This box contains the remains of a router, as well as a battery meter, fuses, switches and a power supply for charging my laptop. The ROV itself is controlled completely from the laptop. The use of Wi-Fi is so that the laptop doesn't have to be directly attached to the tether. This also means that multiple people can connect to the ROV at once and view the live camera feed using their phones.
At the time of writing this post, I am waiting for the ROV's batteries to arrive (so far I have been running it off mains through a step down power supply). As soon as they arrive, I will be able to take it to the lake and do the first open-water test dives. I will try to post some pictures and videos as soon as that happens, hopefully within a week!