Homebuilt ROV questions

[bell47]

I could really use an ROV to look at a few things. I was thinking about building one. Here's the problem....I don't really know squat about them..LOL. I've seen homebuilt ones that used PVC frames and were powered with bilge pump motors. I was thinking the PVC frame would be fine, but what is the best choice for motors? Also, would it be better to have AC power from the boat down the umbilical with a sealed converter to power the DC motors? Wouldn't you be able to have a smaller diameter umbilical this way? It would be easy enough to power it with a small generator on the boat. Also, the homebuilt ones I see always say they are used down to maybe 100 feet. How much harder would it be to make one that will go 2-300+ feet? What is the limiting factors the really deep depths, motors, electronics? I also thought the Camera housing and power may be a limit for depth. Another thing I don't know how the controls work. What type of controls or joystick are you guys using? I don't really know enough to ask anymore good questions. Please let the knowledge flow................. Thanks guys.

[Salvor6]

Bell, start with one of these:
http://www.nventivity.com/roviab.html
Its only $250. You can then upgrade to a deeper depth model, more powerful motors, better controls, etc.

[cornelis 816]

Bell 47 . My advice would be to never buy one of these toys . All you can do is play a little with it . For about $499.- you can build yourself a semi professional unit . It can be used on any wrecksite . Here is a sample of what I mean . I have no plans to build one but if you look good and are OK in using tools you can copy it . The motors are 12V Mercedez heatermotors . As couplings I used super magnets so I do not have to use shafts and seals . Cornelius

[Attila]

my son and nephew made an ROV and took it down the keys.
They ended up on a TV show

http://pbskids.org/dragonflytv/show/rov.html
They limit with the cable is for current verse weight. After 100 ft the cable gets thicker.
this is a problem with the currents in the water. The motors now have to be bigger to drag the cable which now means more current, which now means a bigger cable and it keeps going.

Go totally remote.

We are getting ready to build an advanced model, totally remote.

If you have questions let me know.

[bell47]

Thanks Cornelis, that's about what I need. Is it DC powered from the surface? How deep have you had it? Looks really good. Can you elaborate on the magnet couplings?

[stevemc]

Atilla, remote control wont work under water. And Bell47, the magnetic coupling work by having 2 magnets seperated by a plastic wall. Like Mag-Drive pumps, which are used in saltwater, and the electrics are encased in epoxy, and the pump is driven by a magnet. Works great. If you cant find a drawing of this, look up Mag-Drive and see how they did it. Works a lot better than seals.