Homebrew Underwater ROV

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.'"

Comments

How many weeks?

[Anonymous Coward]

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.

Re:How many weeks?

[Linus Torvaalds]

They had two weeks and a $100 budget.

Re:How many weeks?

[Main Gauche]

Is it unclear that the repetition was probably intentional? Judging by parent's post and its children, I am guessing so.

Generally "real" ROVs cost anywhere from $8,000 up to Millions of dollars. [On the other hand] We had two weeks and a $100 budget.

Informative. ...Usually they have high-resolution camera systems and high powered thrusters to maneuver. [On the other hand] We had two weeks and a $100 budget.

Witty.

MG

Remote control submarines...

[markass530]

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.

Re:Remote control submarines...

[modecx]

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...

[jd]

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.
   

Re:Remote control submarines...

[MeanE]

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.

Re:Remote control submarines...

[darco]

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-detonated mild explosive charge. (With a explosive power similar to that of a black cat, if you are familiar with those types of fireworks).

The CO2 cylinder would be mounted in a small double-capped PVC pipe, with a brass nozzle attached to the cap on the business end of the CO2 cylinder. A tube would be connected to the brass nozzle, which would then be connected to the ballast tanks. The CO2 cylinder would be permanently attached to the opposite side of the PVC with some sort of epoxy. The mild explosive would be detonated using a rocketry igniter.

Remember, this thing is the "oh shit" scenario, so you want to make sure that this thing is gonna definitely work, and you only need it to work once. It doesn't need to be reusable, you would replace it after using it.

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. The tube would be connected to the ballast, and thus the balast would be purged and the vehicle would surface.

Having actually never built one of these things there are a few potential issues:

1) The CO2 that is going to be released is going to be very cold. It is possible that it could freeze the water on contact and jam, which could cause the purge to fail and the vehicle to not immediately surface. (I believe a similar problem also caused the loss of a US nuclear submarine)
2) Puncturing the business-end of the CO2 cylinder with a mild explosive charge may prove to be more difficult than I initially anticipated. I'm sure this could be corrected with experimentation.

Anyway... yeah, fun thought experiment from back in high-school. Shame I never got enough people interested to actually attempt it.

Re:Remote control submarines...

[surprise_audit]

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 fittings. You'd have the airchamber connected by sprinkler valve to the ballast chamber. Crack the valve, the ballast blows.

Re:Remote control submarines...

[TheHawke]

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.

Obviously

[Osmosis_Garett]

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

[obidonn]

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.

ballast of some kind

[infonography]

Could something like AOL CDs or SCO lawsuits work?

Re:ballast of some kind

[Rob_Warwick]

SCO lawsuits?

Everyone knows those have no weight to them.

Re:perhaps that was sarcasm?

[milktoastman]

I think this AC was just joking about the repetitive mentioning of the time and budget constraints in the article summary. Or call it a troll, if you will. Usually that's what anonymous cowards are doing. Probably, he/she WAS just joking about the repetititive mentioning of the time and budget constraints in the article summary. Again, just joking about the repetititive mentioning of the time and budget constrainst in the article summary.

What ir Remotely operated here

[threaded]

This looks like a camera that has been waterproofed and fitted in a frame. Where're the thrusters, the variable balance tanks, grippers, torpedoes.

Stand and deliver, robot style

[Anonymous Coward]

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

Re:Stand and deliver, robot style

[flynnternet]

This story is a must read. Their teachers are doGz...

score 0 my ass, ModUp!

Ah yes, but...

[jd]

Complex geeks start before i1.0! And as for quaternion geeks...

Re:no sandwich tech here

[Anonymous Coward]

I am also hopped up on speed so I know exactly what you're talking about!

Re:To read about real ROVs...

[anagama]

I picked up a copy of "Build Your Own Underwater Robot" some years ago at the Monteray Bay Aquarium. It contains many designs for ROVs built with stuff you can get at Home Depot.

isbn: 0-9681610-0-6

Google Search for the lazy.

Re: Prohibitively Expensive and Complicated ROVs

[some guy I know]

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.

Re:Not as impressive without the thrusters.

[Anonymous Coward]

dude, you can't have everything, after all, they only had two weeks and a $100 budget.

(new slashdot meme +5 points)

We're building one

[dj245]

Maine Maritime Academy 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 contest every year.