myROV version 2.0

Update 11/9-2011

So I finally got a chance to take the ROV out for a test. I knew that there was a buoyancy issue as it floats to high in the water. So I took along a bag of small pebbles and some zip lock bags.
It turned out that I need an extra 700g of weight to get the ROV almost neutrally buoyant in the water. So I’m adding a bracket to hold some square plates that gives me 100g a plate.

The video isn’t all that great but it shows that the system works. Notice the bags on top with blue tape on.

 - end of update -


Update 13/9-2011

I have reprinted the brackets for the battery to accommodate two M8 bolts to hold my ballast weights. The ROV has now an extra 800g of ballast and now I only need some good weather to do a second test.


- end of update -


Some of you might remember my ROV project that I made for my kids and me. It failed miserably as I never got the USB webcam to work over the 15m CAT5 cable and the whole project went on a shelf (it was destined for the bin, but I couldn’t bring my self to throwing it away).

As this is a complete rebuild I’m starting a new page instead of updating the old project. I hope that’s ok.

I felt that my initial design of having 40mm PP plastic tubing to hold the electronics and motors, and the battery below as power source and ballast where sound so I kept this design.
The webcam where replaced by a CMOS/CCD car rear view camera. That had the added effect that I no longer had to bring my PC along to view the video stream. So I bought a cheap 7” LCD TFT monitor and found myself a great case to mount it in.


There are plenty of room inside for my Arduino, power regulator and LiPo battery


And on the lid I have a spool for the cable


The drive system is still the same and uses my custom made stuffing-box / motor mount. They are still driven by the serial motor driver from Pololu The motor drivers work great and I had no problem stacking two of them together inside the 40mm pipe.
I’ve also gotten a 3D printer sins my first attempt and could print out all sorts of stuff for this project.



One of my biggest problems with the ROV was how to get at waterproof connection to the CAT5 cable. I dident want to permanently mount the cable to the ROV so I got myself some waterproof connector and packed Sugru around the cable and penetration. It made a solid but yet slightly flexible bond.


The pipe fittings them self are not glued together but there is a rubber gasket inside the fitting that makes it waterproof. On top of that I added some self vulcanizing tape on the joints to aid the waterproofing. On that several layers of paint.



Some more pictures of the ROV





I got it reassembled after painting today, but it has been raining all weekend so I’ll put up a video sometime next week (hopefully).


cant wait to see this thing in action! very nice job

The tubes were  made with your ToM or you bought them ?

No the tubes and fittings

No the tubes and fittings are regular PP plastic components found in most regular hardware stores. They are used for drainage like your sink and not for water under pressure.
The ToM is great, but the items it produce are not waterproof.


What do you mean ?

Water can pass through plastic printed with ToM ?


I thought any type of plastic was waterproof.

Beautiful build indeed.

Beautiful build indeed. Mr.Andersen~

So the battery will sink into water? How does that work? is it water proofed?

The printer lays down thin

The printer lays down thin threads of hot plastic and there might be small gaps that water can pass through. One might get it waterproof if brushed with Acetone, but not as good (and cheap) as regular over the counter pipes.

It is a sealed lead acid

It is a sealed lead acid battery. So I’m trying it without any waterproofing what so ever.


Really curious to see it in

Really curious to see it in action, i’ll wait for the video impatiently.

Geir you amaze me again!

Geir you amaze me again! :slight_smile:

Well done! I love the command post :smiley:

nice man!

you should really make a clip of this thing man and upload a make of!

I’ll get a video up when I

I’ll get a video up when I get a chance to test it. But according to the weather forecast it doesn’t look good.

Awesome! Absolutely gorgeous

Awesome! Absolutely gorgeous job, Geir!


Andrés “I have the exact same red case” Briano

I don’t know the

I don’t know the manufacturer of the case, but it came as a set of three cases inside each other and this red one is the smallest. The set cost $65 and is well worth the money.

PS. And thank you for the nice comment Andres.

Thank you for sharing, Geir.

Thank you for sharing, Geir. Tremendously inspiring job!

Nowadays, that everything is made in China, it shouldn´t be unusual to find the exact same objets in two places as distant as Norway and Argentina, that, according to google, are 13,520 km apart.

You’re absolutely right

You’re absolutely right Andres. I’m amazed of the production cost and quality of much that is made in China. If these cases where made here in Norway the price would probably be $250 or more.
Just look at some simple 2N3904 NPN transistors. On eBay from China you get 30 transistors for $0.99 (free shipping), and from Sparkfun they are $0.75 each (plus shipping).
OK, so the China transistor might be of a lower quality and some might even not work, but for my hobby that’s no problem.

You’re running this in a

You’re running this in a freshwater environment, right??  :D

No, the plan is to use it on

No, the plan is to use it on both fresh and salt water. Do you see any problems with that?

Exposed terminals

Hi Geir,

Patrick linked me to this post and I had to leave a comment about your design. The exposed battery terminals is going to cause you major problems. In salt water, the battery will cook itself to death as if it was shorted. You can test this if you like. Mix table salt into water at about 1/2 cup to gallon ratio until dissolved. Strip some wires to at least .5" to replicate the same exposed surface area as your battery and put them in the water 1-2" apart and apply 12V from a bench power supply or something else that monitors current. You will get 1-2 amps current draw. I have observed this using water from my salt water fish tanks in a similar experiment.

In fresh water, the immediate danger of cooking battery isn’t so bad, but there will be some current flow between the terminals. You might not notice it right away, but it will corrode your terminals on both the battery and your connectors over time, making you have to replace a working battery and redoing the connectors every so often.

I work for the Navy building robots, and one of the past designs of my base was a crawler or robot that crawled along the bottom of surf zones looking for things. One of it’s power sources was just banks SLA batteries like this, but we had to seal the connections to avoid all the problems. We did it by erecting a box around the terminals with the battery already connected and sealing it all up with epoxy. This effectively gave them permanent pigtails and we used waterproof connectors to be able to swap them in and out.