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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Suggestions for underwater camera housing
I make something for use in swimming pools out of plastic plumbing pipe, but
a fellow I was talking to last night had a more demanding use; design suggestions, and perhaps pointers/offers to manufacture would be appropriate. This fellow needs to have video camera underwater, salt water, on device that is moored to the bottom on cables. The device is mobile, and the maximum depth is around 30 metres, with a video cable run of about 100 metres. Currents range up to about 10 knots. There could be a bit of turbulence, rocks, and general knocking about. Off the top of my head I was thinking that a small surveillance-type camera with a flood light and some sort of video amplifier, all mouted in a small a stainless steel tube as possible, caps and an end window for the camera & light. 30 metres depth is about 100 psi, so sealing will be an issue, but this should just be proper design and workmanship, not innovation. 100 metres of a video run seems like a long way, and as well I do not know if the video cable will be exposed to salt water; probably not, but the possibility should not be ignored. Mounting the device: would welded ears on the tube be likely to fail given the environment, materials, and forces? Or would it be better to have some sort of clamp to grab the tube? There seems to be a need for more than one of these, and although I guessed a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't seemed worried about sums in that range. |
#2
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Suggestions for underwater camera housing
Back in the 70's and 80's when I was big into scuba diving, they had
housing already made to fit the most popular cameras, as well as generic housings. It takes a heap of light at most any depth, lots more than what is needed above surface........All the housings I have seen were always a one piece body that was molded, with access cover. I would think that any solvent welded joints no matter how well made are going to be the weak issue. I owuld check on the web for already made housings. They have come down in price considerably over the years. On Wed, 19 Oct 2005 09:45:41 -0300, "jtaylor" wrote: ===I make something for use in swimming pools out of plastic plumbing pipe, but ===a fellow I was talking to last night had a more demanding use; design ===suggestions, and perhaps pointers/offers to manufacture would be ===appropriate. === ===This fellow needs to have video camera underwater, salt water, on device ===that is moored to the bottom on cables. The device is mobile, and the ===maximum depth is around 30 metres, with a video cable run of about 100 ===metres. Currents range up to about 10 knots. There could be a bit of ===turbulence, rocks, and general knocking about. === ===Off the top of my head I was thinking that a small surveillance-type camera ===with a flood light and some sort of video amplifier, all mouted in a small a ===stainless steel tube as possible, caps and an end window for the camera & ===light. === === === ===30 metres depth is about 100 psi, so sealing will be an issue, but this ===should just be proper design and workmanship, not innovation. === ===100 metres of a video run seems like a long way, and as well I do not know ===if the video cable will be exposed to salt water; probably not, but the ===possibility should not be ignored. === ===Mounting the device: would welded ears on the tube be likely to fail given ===the environment, materials, and forces? Or would it be better to have some ===sort of clamp to grab the tube? === === === ===There seems to be a need for more than one of these, and although I guessed ===a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't ===seemed worried about sums in that range. === ============================================== Put some color in your cheeks...garden naked! "The original frugal ponder" ~~~~ }((((o ~~~~~~ }{{{{o ~~~~~~~ }(((((o |
#3
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Suggestions for underwater camera housing
On Wed, 19 Oct 2005 09:45:41 -0300, "jtaylor"
wrote: I make something for use in swimming pools out of plastic plumbing pipe, but a fellow I was talking to last night had a more demanding use; design suggestions, and perhaps pointers/offers to manufacture would be appropriate. This fellow needs to have video camera underwater, salt water, on device that is moored to the bottom on cables. The device is mobile, and the maximum depth is around 30 metres, with a video cable run of about 100 metres. Currents range up to about 10 knots. There could be a bit of turbulence, rocks, and general knocking about. Off the top of my head I was thinking that a small surveillance-type camera with a flood light and some sort of video amplifier, all mouted in a small a stainless steel tube as possible, caps and an end window for the camera & light. 30 metres depth is about 100 psi, so sealing will be an issue, but this should just be proper design and workmanship, not innovation. 100 metres of a video run seems like a long way, and as well I do not know if the video cable will be exposed to salt water; probably not, but the possibility should not be ignored. Mounting the device: would welded ears on the tube be likely to fail given the environment, materials, and forces? Or would it be better to have some sort of clamp to grab the tube? There seems to be a need for more than one of these, and although I guessed a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't seemed worried about sums in that range. 30 meters of depth is only about 50 PSI of pressure. Surveillance cameras only need a small window. This should not be difficult at all. You'll want to purge the housing with dry nitrogen (or argon from the TIG welder) before sealing, to avoid condensation at cold depth. I'd put a dessicant pack in there as well. Attenuation of RG59 cable is only about 1 dB/100 ft at video frequencies. You shouldn't need a video amp. I would not house the light with the camera because of thermal considerations. Use a dive light that is already packaged for depth. The light is probably the more difficult problem, and many models are commercially available. |
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Suggestions for underwater camera housing
On Wed, 19 Oct 2005 09:45:41 -0300, "jtaylor"
wrote: I make something for use in swimming pools out of plastic plumbing pipe, but a fellow I was talking to last night had a more demanding use; design suggestions, and perhaps pointers/offers to manufacture would be appropriate. This fellow needs to have video camera underwater, salt water, on device that is moored to the bottom on cables. The device is mobile, and the maximum depth is around 30 metres, with a video cable run of about 100 metres. Currents range up to about 10 knots. There could be a bit of turbulence, rocks, and general knocking about. Off the top of my head I was thinking that a small surveillance-type camera with a flood light and some sort of video amplifier, all mouted in a small a stainless steel tube as possible, caps and an end window for the camera & light. 30 metres depth is about 100 psi, so sealing will be an issue, but this should just be proper design and workmanship, not innovation. 100 metres of a video run seems like a long way, and as well I do not know if the video cable will be exposed to salt water; probably not, but the possibility should not be ignored. Mounting the device: would welded ears on the tube be likely to fail given the environment, materials, and forces? Or would it be better to have some sort of clamp to grab the tube? There seems to be a need for more than one of these, and although I guessed a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't seemed worried about sums in that range. --- either: http://www.google.com/search?hl=en&q...amera+housings or: http://www.austininstruments.com -- John Fields Professional Circuit Designer |
#5
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Suggestions for underwater camera housing
On Wed, 19 Oct 2005 09:45:41 -0300, "jtaylor"
wrote: There seems to be a need for more than one of these, and although I guessed a figure of $1000 for a cheap proof-of-concept unit, the fellow didn't seemed worried about sums in that range. How many do you need? I can supply them by the car load. http://www.harborfreight.com/cpi/cta...emnumber=91309 Gunner "Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules. Think of it as having your older brother knock the **** out of you for torturing the cat." Gunner |
#6
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Suggestions for underwater camera housing
I just saw a piece on our local news last night about a couple of guys
who build homemade underwater ROVs. Most of the parts are PVC plumbing fittings, available at the local hardware store. I have some 1.25" Schedule 40 that is rated for 370 PSI. That's internal pressure. It might be good for even more externally. -- Paul Hovnanian ------------------------------------------------------------------ Klein bottle for rent -- inquire within |
#7
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Suggestions for underwater camera housing
--If it's going to get bumped or dragged along the bottom
you'll want something tougher than PVC pipe. Under pressure with a pointy side load it might collapse. Also there's the matter of the end caps. They'll need to be thick and at least one will have to be removable. The traditional method is to have it screwed onto a housing that has sufficient surface area on the sealing edge to accomodate an O-ring in a groove and a dozen threaded fasteners. Best way to do this would be to lay up your own housing using fiberglas. I've got a buddy who used to make camera housings and that's the way he did it. IIRC he used threadserts in predrilled holes to hold the faceplate bolts. A light bar could be attached in a similar way with threadserts in other parts of the housing. The O-ring groove was molded in as a half-round groove by using half-round dowel glued around the base of a male plug mold. One great advantage of a fiberglas housing is that you can make it conform tightly to a specific camera shape, so that ballasting is not as big an issue. -- "Steamboat Ed" Haas : When does Inuyasha get Hacking the Trailing Edge! : to bone Kagome?? http://www.nmpproducts.com/intro.htm ---Decks a-wash in a sea of words--- |
#8
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Suggestions for underwater camera housing
I would be cautious about using stainless steel. Might be okay, but
without disolved oxygen in the salt water, stainless corrodes. Powder coated aluminum would be better. Recommend using both piston and face seal orings on the end caps. You don't need much to keep it together. Dan |
#9
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Suggestions for underwater camera housing
jtaylor wrote:
I make something for use in swimming pools out of plastic plumbing pipe, but a fellow I was talking to last night had a more demanding use; design suggestions, and perhaps pointers/offers to manufacture would be appropriate. http://www.bhphotovideo.com carries many types of underwater camera and lighting housings. May be cheaper to buy than build. Richard |
#10
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Suggestions for underwater camera housing
My local supermarket was selling stainless steel lidded canisters for food
storage. The lids had round plastic windows. With a bit of extra sealing, maybe they might do for modest depths? |
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