Homebuilt ROVs Forum

I have been away for too long time. While I was waiting for the winter to pass I started playing around with FPV and before I know it I was dragged into building multi rotors for professional AP. Now I am back (seriously.. to finish this old project.

The first attempt viewtopic.php?f=18&t=445 worked Had no problem with leaks, controls and motors. I was using the old ROV Asia board. I made it to about 20 meters in saltwater BUT since I was sending power from top side the cables became very heavy and made it impossible to go further. The rest worked so I decided to keep the design but made a more professional hull and switched to DSC control that forum member bikerbones (still around?) recommended.

The Mark II has batteries in the hull so only Cat cable went to surface. Still working on flotation, just had some temporary isolation foam to get an aprox on what I will need. The new setup:
I also got a bag of seacon bulkheads that I plan to use.
The main problem I had (and have ) with the new setup was that the signal started flipping in saltwater. Didn't understand really what was going on since all was good in regular water and then when submerged it started shutting on-off motors randomly. You can see on the video that it starts driving itself in the water. later I found that saltwater got inside of the Ethernet cable jacket where only ground wires are exposed and I don't know if that was the problem. Would appreciate if an electrician can help me with that.

I decided to gradually move all batteries outside the main hull. One (of several) reasons is that I find it too complicated to open the hull, connect, turn on, close before a dive. Also I would like to be able to change packs while on the water.
Made a small 5A pack to start with. This will be dedicated for lights, waiting for pcb and connector to arrive to fully assemble. For the motors and rest of electronics I was thinking about a 15-20A pack to compensate for the relatively low c rating of li ions?

After just seeing Kenl's POST thats a pretty good idea with the batteries.

-Steve

Yeah, feel sorry for Kenl, but that was not one of the reasons I am moving out (now it is though). Either way I believe moving from Lipos to li-ions for our applications is a good idea. I don’t think Lipos are that unsafe if handled correctly. I was following safety discussions and tests conducted on Lithium polymer and 99% of all accidents are due to wrong handling, bad charges and heavy discharges.