Picture of Underwater ROV
This instructable will show you the process of building a fully functional ROV capable of 60ft or more. I built this ROV with the help of my dad and several other people who have built ROVs before. This was a long project that took al summer and part of the beginning of the school year.
ROV Video.AVI(320x240) 48 MB
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Step 1: Design

Picture of Design
Rollette ROV.jpg
In order to keep the ROV stable in the water, you need a design that is weighted on the bottom and has floats on the top.

The first ROV was built by Steve of Homebuilt ROVs. His website has numerous ROV designs as well as links to other ROV websites. He also incorporates several How To instructions in his site. I found this site to be invaluable in building my ROV, and would recommend it to anyone interested in building their own

The second ROV was built be Jason Rollette at His design is a little different but still very effective.

For my ROV I decided on a large center tube with two smaller tube located on either side, slightly underneath the center tube.

Step 2: Frame

Picture of Frame
Here is the beginning of the frame I am building for the ROV. I cut plexiglas windows and sanded them to fit inside the pipe. This is Schedule 40 ABS pipe, commonly used for sewage. When joining this pipe, make sure you use solvent glue that is specifically made for gluing ABS. Normal PVC cement will not work or create a poor bond that could leak. I am also using a marine sealant to seal the plexiglas and prevent water from coming in. On the back end, I am using screw plugs in case i need to access the batteries or electronics again. I will need to wrap the threads in teflon tape to make it water tight.

After some testing, I found that the screw plugs leak, so I switched over to rubber end caps that have a band clamp to secure them.
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harry882 years ago
You could use an air compressor and an electronic valve to let in water and another to let in Air to a ballast tank but it would add another 30 + dollars in airhose and valves
perfo harry882 months ago

As long as it's a non compressible hull then you don't really need controllable ballast tanks. Once you set it to neutral buoyancy then it'll stay at neutral buoyancy and require very little power to move it up or down. As neutral is hard to get I would opt for slightly positive or negative depending on one or two things. If you want to predominately look at things on the bottom then I would opt for very slightly positive buoyancy. This is so the thrusters don't throw up all the crap on the bottom and ruin your view. As long as the tether is strong enough to retrieve the ROV with if you get a fault then no problems with slightly negative either. If very near neutral then the power needed to stay put or move up and down is minimal so IMO not worth the effort and complexity of controllable ballast..

If you need to alter ballast due to picking something up or dropping it off then you could use a bladder in the weighted section of the ROV. That is put a balloon in a chamber at a little bit of pressure (greater than the dive pressure) then use a water pump to put water in to the chamber . As long as the water pump is higher pressure than the balloon then water will enter the chamber and the ROV sink. As the pressure equals the balloon pressure it will then be static and if less then the water will be forced back out. As long as the pump can deliver the pressure then as the balloon collapses the pressure needed to put more water in will increase. So a speed controller on a centrifugal pump with a bladder chamber will give you buoyancy control. Whilst this will work it would require constant power on the motor so if you need if for long period then valves could be used but again more complexity...

BJMN6 years ago
I have a quick question - I remember learning in school that water is opaque to IR. My wife is a certified IR photo tech, and I know that our IR camera won't show things even just a few millimeters under the surface of water. Is it really IR that these cameras use?
SpaceShipOne (author)  BJMN6 years ago
My camera is not an IR camera, but Sparkfun carries a similar model in IR. I do know that most people use night vision cameras, similar to the types that can be purchased form fishing stores. I have also heard of B&W cameras being used, since they are IR sensitive.
Hmm - just curiosity, since I don't doubt you've researched more than I! But to rephrase my question - since water is opaque to IR, wouldn't IR cameras be relatively useless underwater? If B&W cameras were IR sensitive, wouldn't they still just be picking up the visible light spectrum, since water emits an even IR level? Anyhow - not looking to troll this thread out - but still curious as to how an IR camera would function underwater!
perfo BJMN2 months ago

IR is one of the worst frequencies of light for penetration under water. If you have enough IR light and a sensitive enough camera then of course it will work. Blue and green penetration a lot better but then give you odd shades on your video... White light gives you the best all round visibility but you may have to accept you are going to have to get pretty close to get a perfect picture with good colors...

In short it isn't a matter of working yes or no... frequencies of light will work but to different degrees and the IR end of the scale is a lot worse than the ultravilot end...

rrrmanion BJMN5 years ago
maplin seem to be selling a camera that is apparently able to see up to 7m it has 12 IR LEDs, so it seems IR does work under-water so perhaps how you had it set up or something I don't know
Red light can penetrate up to 15 meters in water. Most b&w cameras pick up near infrared that is between red and true  infrared. So 7m sounds reasonable. Like any light it would be limited by suspended particles in the water.

SpaceShipOne (author)  BJMN6 years ago
I don't know for sure, but it could be that water is opaque to only certain wavelengths of IR.
mlucas62 years ago
Hi really nice ROV i am looking in to this for surf fishing as in towing out my line bait and all past the 3rd sandbar thats about 200 yards or a bit more would it work with that long of a tether?
perfo mlucas62 months ago

fiber optic and go for 1 Km as long as the tether doesn't snag or currents etc challenge your thrusters. However do you need 200m straight down ? If not then connect the ROV to a bouy that floats on the surface and put a sturdy bit of rop to the buoy. Comms can either be via radio to the bouy (even wifi) or fiber / cable. The bit down to the ROV is still then light weight and manageable.

SpaceShipOne (author)  mlucas62 years ago
200 yards is a bit of a stretch for the signal I am using to communicate with the ROV. If you switched to something more robust such as I2C or a serial data connection it would function better . Remember that the tether will become an antenna as it is fed out so using a RC style controller would be impossible due to all the interference you would get. If all you plan on using this for is towing a line then I would recommend a stronger forward/reverse thruster system as you will need to overcome the drag of both the tether and your line, not to mention any kind of current.

Good luck!
dfair441 year ago
Any issues with Cat5 leaking? I was thinking of using an Arduino with webserver so that I can control the ROV over the cat5 from my laptop. Camera is a 9v balun cable connection so I can see and record through the laptop.
perfo dfair442 months ago

Cat 5 leaks, It may take a while depending on the depth but it is semi porous and thus will eventually leak. however if you just intend to use it for an hour then get it out and let it dry through then you'll probably get away with it. The other problem with Cat 5 is flexibility , some cables are more flexible than others but some kink and make control of the craft more difficult. If you are not going to transmit power down your tether then why not use fiber optics and a media converter either end.. You can if you so desire put a router in your ROV and have as many IP CAMs as you wish (within reason)

this is a great idea! i think i might update mine to use this method, assuming the Cat5 workes well. i just had left over wires i strung together, and it was a mess!

rov man9 months ago

amaing realy

Mojon11 months ago

Every tutorial I have seen to build these all ways leave you with queations. I have a 100 foot ethernet cable and I would like to know how I can send a signal to something that turns on a switch to power the on board batterys. and another thing, your batterys are only 2.5 amps and they power two 3 amp motors? it doesn't finish here, how can I send out signals from a laptop to the relays?

SpaceShipOne (author)  Mojon11 months ago

Using batteries was an attempt to get around the problem of sending high current over a long wire. In hind sight, this was not an idea solution. To prevent voltage drop, heavier gauge cable must be used, which weighs more. Commercial ROVs get around this by sending high voltage at low current, and then converting it down to the required voltage. Foe example, if you need 500W to run the ROV, you could send 10 volts at 50 amps (P=IV), or 500 volts at 1 amp.

Communications can be handled by a wide variety of interface cards, it depends on what protocol you are using. I would recommend using some kind of serial comms, like I2C or SPI to cut down on the number of wires your tether needs to have. On off control from the surface would need 1 line per relay, assuming they share a common ground.


Zaqq1 year ago
This has to be one of the coolest Instructible I have seen in a while.
mwuchevich3 years ago
Was wondering if their is any ill effect for use in cold ocean water... I just moved to norway and im currently evaluating what design parameters i will need to help me study the submarine geology in the current area. Any informaiton about cold water performance would be grately helpful. Considering rock retrival video and some type of sonic rebound reflective maping device.. just not finished with research.
also any ideas about cancling neutral boyncy after retreaving objects on a dive? sorry for the sp its late and brain not spiting out words to fingers correctly.
Sorry for the late reply, but for things like RC planes you can get a little mechanism called a bomb drop which is a pin that slides and allows you to drop things, you could attach rocks to the bottom and drop them when you pick things up.
SpaceShipOne (author)  mwuchevich3 years ago
Cold water is not much of a problem provided you use seals that are meant for colder temperatures. Most commercial ROVs operate at depths where the water temperature is significantly colder than the surface.

When retrieving items, you will either need powerful enough motors to lift the object or some kind of inflatable lift bag to give you the added buoyancy you need. Alternatively you could use a tether that has a lifting line which you could use to haul your ROV to the surface
jakeson1 year ago
Any luck with those videos and perhaps I missed this, but how did you attach the black abs to the PVC in the end, did you stick with ZapStraps?
Very nice!
grundisimo3 years ago
Try using pumps and ballast tanks to control weight.
Legoman1324 years ago
I am building an ROV myself, and I was wondering ow far your lights penetrated in cloudy water. Also, I flound that the 1250 GPH bilge pump replacement cartridge from West Marine doesn't need cutting to get to the motor shaft, and I got some boat props from hobbytown that fit the shaft perfectly, just tighten the key and go. The only issue is they produce more thrust in one direction than the other. Do you have the same issue? I also find that mounting your motors with PVC pipe clamps (in the 1 1/2 inch realm I think) and some old bicycle inner tube around the motors holds them on solidly, and you then put some bolts through the frame PVC (assuming your frame isn't watertight). This forms a very solid mount(at least for me) that doesnt move. It also doesn't crush your pipe like pipe clamps do.
Because of the shape and design of a propeller, and the way it's mounted on the motor, they produce more thrust in one way than the other. It's a problem all prop-driven ROV's must design around.
R.A.T.M3 years ago
If you're going to use the submersible bilge pumps as motors, why not use them as they are, without propellers,  for jet propulsion?  You could even increase the force of the jet by by graduating the discharge down to a smaller size.
Propellers have the advantage that they can be run either way for forwards and backwards - they'll also give more thrust (though draw more current as a result.)
MR JAMES4 years ago
cool i want 1 of these lol
ghostrider24 years ago
how much was the total cost of the project?
SpaceShipOne (author)  ghostrider24 years ago
about 300$, depends on how complicated you make it
hi any idea if we can get the codes and circuit diagrams for this whole project so that we can implement as well please. Thanks
quesoman5 years ago
is a video of the ROV in action possible?
"This is plenum rated Cat 5, meaning that it can be pulled through walls using a fishtape."
...could be wrong, was couple times afore, but I think 'plenum' cable is cable which uses insulation that does not produce harmful vapors when burned. In some commercial buildings, a/c return-air is run (without ducts) in the space between the room ceiling and the floor above it, ie the 'plenum'. If a fire ever broke out, this specially-designed 'plenum' cable would not release toxic fumes into the a/c system air flow which would injure or kill all living creatures within the air conditioned space.
Other than that, thanks for the info here. I have been working on my own system, mostly to get live pics in the canals here in S. Fla. My interest is in getting the 'real' closeups of the many 'gators that live here; maybe one day I'll get some neat shots as my mini-cam gets swallowed whole!
your dog5 years ago
would be a good camera?
it also has infered so you would not have to buy lights be a good camera?
You spelled infra-red wrong
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