I have been watching the videos on youtube with respect to your 320m dive. Impressive I must say.
I have a couple questions for you. Why are you positioning your lights outside of the ROV frame now please? How much umbilical were you using from the sled?
Thanks for the kind words! We’ve been positioning the lights on the outside of the frame to get them further from the camera, which gives a better image with less backscatter and reflection. Ideally we could them much further out from the camera but that would be impractical.
We were originally using 50m of the tether from the sled, but on our second dive we reduced that to about 25m because 50m was way too much. We expected to travel away from the sled but since the lighting was so good in front of the sled we stayed in that area mostly.
No, there’s not tether management at all. The entire length of tether was out in the water all the time. That wasn’t the best because there’s a big loop of cable out behind the tow sled that could snag on things.
To reduce tether length we just zip tied a bunch of it up to the sled.
I wonder if a really weak constant retraction spring would work. You would get some pull on the ROV, but thrusters should be able to compensate. That or maybe make a servo into a cable winder.
I think a ROV garage sled is going to be one of my next projects. I’m thinking a big aluminum box with a flared mouth and rollers, windy spool for short cable on top, lightbars everywhere, and float stuff on the side for neutral buoyancy