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Robotics Hardware Hacking Hardware

Homebrew Underwater ROV 137

Posted by timothy from the blub-blub-blub dept.
Blue-Footed Boobie writes "A very geeky member of TechReport has built himself a homebrew Underwater ROV to use while on vacation. For what they said was 'Version 1', I would have to say the results were great. Full build log, with videos, can be found here. Good job guys! 'Being the geeks that we are, we always come up with some sort of project to bring up to the lake and play with. This year, two weeks before vacation, we decided to build an Underwater ROV. For those not familiar, an ROV is a Remotely Operated Vehicle. Generally "real" ROVs cost anywhere from $8,000 up to Millions of dollars. We had two weeks and a $100 budget. Usually they have high-resolution camera systems and high powered thrusters to maneuver. We had two weeks and a $100 budget.'"
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Homebrew Underwater ROV

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  • How many weeks? (Score:5, Funny)

    by Anonymous Coward on Sunday July 31, 2005 @01:58AM (#13206129)
    And how much was the budget?

    The writeup doesn't make it clear.

    I read the writeup. But the writeup doesn't make it clear.
  • As a former submariner I would love to have one to play with, but they seem prohibitively expensive and complicated, wonder if anyone here has experience with one? Then also the thought of loosing one would be nerve racking. Not sure if you could equip a toy with an emergency blow apparatus.
    • Not sure if you could equip a toy with an emergency blow apparatus.

      Most likely you would have to give it ballast of some kind. How about an automatic release mechanism attached to the ballast attach point? It could be a simple electronic timer driving an electric motor with a pulley. String winds up on the pulley and pulls a pin which releases the ballast.

      Or just operate it with a tether until you are confident it will always come back.

      • Could something like AOL CDs or SCO lawsuits work?
        • AOL CDs would work, but you'd need a lot of them. CDs sink, but not very fast. It took a couple seconds from being inserted into a tub of water for my experimental CD to drop a couple inches to the bottom.

          On the other hand, while I don't have any to try, I have a strong feeling that the SCO lawsuits would float. Actually, I suspect they would not just float out of the pond/lake/etc. but also up into the upper atmosphere because of the quantity of hot air contained within.
          • In retrospect I think that experiment I did sheds no light on it. I think I just made the traditional "heavy objects fall faster" mistake, just shifted so that "heavy" was "less bouyant" and "fall" was "sink." At the time I was thinking that would make a difference, but falling is really just sinking through air, so I don't think it actually would.

            Still, CDs aren't very dense.
        • SCO lawsuits?

          Everyone knows those have no weight to them.
      • All submersible ROVs (Remotely Operated vehicles) are tethered. Water absorbs most radio signals and light signals within a few metres. In order to get any sort of decent range (like the 100 ft mentioned in the article) you need a tether or umbilical. It is the UAVs (Underwater Autonomous Vehicles) that might need an emergency blow aparatus.
    • Not sure if you could equip a toy with an emergency blow apparatus.

      Sure you could... Heck, McGuyver could do it with a CO2 cartrige, a few pieces of ABC bubblegum, a nail and some weathered rubber bands.

    • Re:Remote control submarines... (Score:5, Interesting)

      by jd ( 1658 ) <imipak@ y a hoo.com> on Sunday July 31, 2005 @02:34AM (#13206249) Homepage Journal
      Seems easy enough. Three ways you could do this:


      1. Motor running to a pin, holding some ballast. You trigger the motor, the motor slides the pin back, the ballast is dropped.
      2. The slightly geekier way would be to hold the ballast in place with electromagnets. The power to the electromagnets goes through a relay, which is held shut by a keepalive signal. Kill the signal (or the signal is lost for some other reason), the relay opens and the ballast is dropped.
      3. The slighty more geeky way would be to have the line running to the submersible corrigated in some way. The line runs through some toothed wheels attached to a motor. If the keepalive is lost (killed or lost signal), the ROV disconnects the control line from the computer and switches on the motor, "climbing" the control line back to the operator.

      • Why not just pull the cable?
      • The slightly geekier way would be to hold the ballast in place with electromagnets.

        Be sure to bring many spares, You will drop a bunch just during "normal" dive preparations. I would consider a manual locking mechanism that is disengaged just before the dive begins. Also be sure to train any divers or swimmers to *never* go under the vehicle.
      • Kill switch on electricity lost is good but if you have a mechanical failure where you still have power available there could be a problem. If the lake is deep enough you may drop too deep where the air inside the sub is too pressurized to float even when the ballast is released.

        If you use a cO2 cartrige that had the firing ping energized with magnetics, you would definatly have enough lifting power for any reasonable depth, just need a heavy balloon or parachute.

        I'd like to see some sort of mechanical swit
        • If the lake is deep enough you may drop too deep where the air inside the sub is too pressurized to float even when the ballast is released.

          A good point; the solution would be to use a buoyant liquid, like diesel fuel, instead of air. Cheap and effective.

    • Re:Remote control submarines... (Score:5, Informative)

      by MeanE ( 469971 ) on Sunday July 31, 2005 @02:41AM (#13206264) Homepage
      Well I have a friend who does this sort of thing (currently 200k off of Newfoundland I believe), and all the commercial ROV's he has worked with have positive buoyancy, lose power and it floats up.

      It is quite interesting stuff, he works with ones that are just simple cameras, all the way up to larger ones with multiple arms and tool attachments.

    • Not sure if you could equip a toy with an emergency blow apparatus.

      Actually, this is something that I have given a considerable amount of thought to, as I was planning on building something similar in high school.

      The mechanism would use a standard CO2 cylinder, the kind that is usually punctured with a needle and used to power pellet guns, air dusters, etc. Except instead of puncturing it with a pin (which sounded a bit too complex and prone to failure), it would be punctured using an electronically-detonat

      • The mechanism would use a standard CO2 cylinder, the kind that is usually punctured with a needle and used to power pellet guns, air dusters, etc.

        Try googling for "paintball cannon". I won't post links, but there are some detailed instructions for building a paintball cannon. The part relevant to you would be the gas release from the airchamber. Homebrew cannon often use a lawn sprinkler valve. The air chamber could be charged from a regular air compressor, but some of them use the CO2 bulb screw-in

        • Make it easier, instead of cobbling a balloon kit together, go get a inflatable life jacket (type I or II USCG) and hook it into the ROV with something to pull the release cord. Something goes wrong, the tube's inflated and the ROV rises to the surface.

          Odds are that the umbilical will get fouled and will have to be cut to free the unit so consider a simple set of shears with a high-tension spring to deal with the cord in case something should happen.
          • This is not a balloon system, it is an emergency ballast tank purge. Under nominal operation, the ballast tanks would be used control the ability to sink/rise, using a mechanism to electronically flood/purge the tanks. This is an entirely separate system than the emergency purge mechanism, which would only be used in the event of some sort of catastrophic failure.

            At least, that was how I designed it.
            • Forget the life vest - the guy's a loony... What would that cost anyway??

              From reading about one paintball cannon, the vc tubing is good for over 100psi, and the sprinkler valve is good for maybe 120psi. I believe some sprinkler valves are operated by 12v solenoids, so if you can get 12v down to your ROV, you're cooking. One site I looked at was http://corin.com/bill/paintball/aircannon/ [corin.com]. He put a bicycle valve on one end of the airchanber, then pressurised it using a bicycle pump. Same could be achieve

      • Mightn't it be easier to adapt the ordnance from an automobile airbag? That's a similar case of "must definitely work and needs to work only once."
        • Perhaps it would. This would also fix the whole freezing problem. However, that stuff is quite volatile, and would react much more explosively than a punctured CO2 cylinder. Without very careful testing, it would likely cause a catastrophic underwater explosion which would result in the loss of the vehicle
      • When a suitable electronic pulse is sent to the device(~6 volts), the explosive charge would detnoate, rupturing the CO2 canister and releasing the CO2 into the tube attached to the nozzle.
        How about just using an explosive to blow the water out of the bottom of a tube sealed at the top? You might not need the CO2 canister at all.
    • As a former submariner I would love to have one to play with, but they seem prohibitively expensive and complicated [...]
      My understanding, based on what I read somewhere, is that it's possible to build one yourself if you have two weeks and a $100 budget.
    • Not sure if you could equip a toy with an emergency blow apparatus.

      What about a sex toy?
    • An emergency blow apparatus is probably not enough. You may also need to detach the umbilical.
    • While not as cool as the one in this article and probably not quite what the former submariner is looking for...My 5yo son and I have fun with the RC submarine we picked up at Walmart for $19.99.
      Once you get it properly balanced, it is just slightly positively buoyant. This means that you have to always provide downward thrust to keep it submerged but it also means that you are less likely to lose it.
      For $20 it is fairly sturdy and gives you full control:
      forward/reverse,
      left/right
      submerge/surface
      All using
    • Some remote control submarines are wildly expensive, others are not. See HobbyTron [hobbytron.com] for the $20 "zip zap" of radio control submarines, for instance.

      A quick google for "remote control submarine" will get you a lot of relevant links. A scale model may not be what you're looking for, but it will get you a lot of useful information on what you can do, and where to start.

  • Quite interesting, though I'd have been a bit more impressed if they'd managed to install some better controls on it.
  • Titanic anyone?

  • Real geeks know that versioning starts before 1.0 :)

  • He built an underwater ROV and posted the pictures inline so that he could find the server after the slashdotting that is on the way.

  • ROV, Without the R or O or the V (Score:3, Insightful)

    by obidonn ( 590065 ) on Sunday July 31, 2005 @02:21AM (#13206217)
    Hmm, it seems like it's actually a frame with a camera inside it, that they sink and lift up. Which means it's not really Remotely Operated or a Vehicle. But really nice footage! Bluegill and perch have very cool coloring. And from growing up in Indiana I can tell you their heads even after being severed will continue gasping for air up to half an hour.

  • What ir Remotely operated here (Score:4, Insightful)

    by threaded ( 89367 ) on Sunday July 31, 2005 @02:26AM (#13206231) Homepage
    This looks like a camera that has been waterproofed and fitted in a frame. Where're the thrusters, the variable balance tanks, grippers, torpedoes.
  • The implications for amateur researchers, or even just regular fish and Game employees. Sheesh for 100 bucks you could afford to lose one now and then. I would also imagine that fish hatcheries would find this tech interesting.

    Maybe I'm just behind the times. The videos kept making me think of the "Titanic" video from National Geographic, I thought it was the coolest thing when I was a kid. Someday when I have 100 dollars to spare I will have to make one of these things.

    Awesome ideas guys!!!
  • Tie a 5lb weight to a $15 underwater disposable camera. Attach Rope. Could have done this with 85 less dollars, and in 20 minutes instead of two weeks.
    • Let's see you do it then. Please post pictures and videos of the result!

      It's easy to bitch and complain about creative things that other people are doing. It's a whole different thing to actually get around to doing something yourself.
    • There are many reasons that their approach is better than the one you posit. The most important is that they actually have a platform to continue to make improvements. They figured out how to make the electronics replacable and how to construct a tether for power. They are also on their way to having adjustable buoyancy.

      Other posters have pointed out that submersible motors can be had relatively inexpensively. Next summer, they could spend another $100-200 and get thrusters installed. Or install pumps

  • Stand and deliver, robot style (Score:5, Interesting)

    by Anonymous Coward on Sunday July 31, 2005 @02:41AM (#13206265)
    That's pretty cool, but this story about four underpriviledged high school kids from Arizona and their ROV is worth a read. With little funding and experience, they take on college students and, well, you'll see...

    http://www.wired.com/wired/archive/13.04/robot.htm l [wired.com]
  • "The page you requested cannot be displayed because the user is over their daily bandwidth utilization" Ha...maybe they should use the ROV to host their pics
  • Ours isn't a true ROV because we didn't have the time/budget to do Thrusters. So, we call ours a Towed Remote Observation Vehicle or tROV
    Nothing to see here - well maybe the paint job?

  • We're building one (Score:4, Interesting)

    by dj245 ( 732906 ) on Sunday July 31, 2005 @05:01AM (#13206583) Homepage
    Maine Maritime Academy [mma.edu] is building a small rover too. Someone on the team had the brilliant idea to use sump pumps for propulsion- they're submersible, they're 12v, and they take the saltwater ok. We're working with our Marine Science and Marine Bio majors and lend them the rover whenever they want it. Currently its running off a tether but hopefully we can get some sort of remote control soon. Waterproofing the batteries seems to be the hardest problem, although various Junkyard Wars shows would have me believe otherwise. This is all mostly for a Society of navel and marine engineers [sname.org] contest every year.
    • This is all mostly for a Society of navel and marine engineers contest every year.

      They have engineers for navels now? Man, that's specialised!

      Coming soon on National Geographic! Navel engineers investigate "The Secret of the Blue Lint"
    • Actually, just clarifing a few things: 1) We have a primary version built, but its pretty much a proto-type, working on next gen version now. Hopefuly we'll get some of our new ideas implemented this year. 2) The Marine Science department has there own ROV that we played around with once or twice to get ideas from. There's was a commercialy built/sold version that has a fancy video camera. 3) The contest is for MATE [marinetech.org] not SNAME. Its just pretty much the SNAME section who has been working on it. Similar ci
    • Keep in mind that sump pumps are designed for intermittent use. You may have some reliability issues if you use them at a duty cycle that is more than 5% or so.

      Good luck, sounds like fun!

      -Adam
    • Keep the tether, or be prepared to include triple-redundancy on multiple systems. The last thing you want is a technical failure to result in the complete loss of your ROV.

      ~UP
  • Was it me, or Wikipedia wasn't answering ? Did you attempt to slashdot it ???
  • seems the site has been slashdotted. well, not the site itself, but the user hosted his images/videos on his adelphia account and it's been blocked for bandwidth reasons.
  • How much time did you have, and what was your budget?
  • that guy at the end of their thread called us vultures ;(
  • Yeah, so this is cool and everything...

    But does it run Linux?
  • I'm really tired of hearing about Bush's campaign advisor ... oh! ... never mind ...
  • Both the Images and Videos are back up!!

    Thanks to PhotoJerk.Com for the space!

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