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DropCamera system


(CSquire) #1

Would like to share a drop camera system design based on BlueRobotics 4 inch tube. System has one downward facing pan/tilt cam and one horizontal panning camera. The lights for the downward cam are external led while the pan cam has an internal led light which pans in sync and is mounted about 12-14 inches above the camera itself to reduce backscatter effect. The drop cam also has a hydrophone, water velocity sensor, depth, water temp and compass. A fin is to keep the unit from spinning in a current and align with water current. To rest on the bottom a weight is attached to the unit by a short tether and holds the system on the bottom while the added buoyancy keeps the system upright.

The system is powered by a custom Li-ion battery pack. There a three arduinos for processing, one for subsea, one for surface control and one to do the video overlay. The are also several custom pcbs. The tether right now is based on a heavy duty cat5 cable with a braided outer jacket and a heavy kevlar rope feed thru the braided jacket along with the cat5 cable. Most all the internal parts and modules are 3d printed and the framework is made from 3/4 inch HDPE sheet.

The drop camera is meant for use by a local non-profit marine science center during trips offshore with youth and adults to view and hear the marine enviroment first hand where now they just can see the surface. Design and build are fairly well along.

any comments, questions or ideas are appreciated.

 




(Rusty) #2

Hi Crans,

This is looking great. I like it.

I’m curious about the rings around the center of the enclosure. Are those for protection or do they serve another purpose?

I really like the 3d printing used for all of the internal elements. We’ve been doing some similar things for prototypes and it’s great.

Has this been tested at depth yet? I’d love to see some pictures or video taken with it.

Nice job!

Best regards,

Rusty


(CSquire) #3

Thanks Rusty,

the rings around the tube serve multiple purpose.

  1. add rigidity to the threaded rods assembly
  2. extra protection for the main tube
  3. mounting points for additional small pressure tubes containing extra instrumentation, i.e salinity sensor etc. that may be added in the future.
have not yet pressure tested in water yet, still waiting for framework to be cnc cut.

could not have done this economically without the 3d printer technology

Will for sure post video and pics when we get some.

 

 


(Rusty) #4

Okay. Are the rings squeezed on there tightly? I only ask because we’ve seen the tubes used in a few situations where they are squeezed or stretched and it tends to make them more brittle and more likely to crack if hit. I’d recommend that the rings on the outside don’t squeeze the tube too hard.

Looking forward to pics and videos!

-Rusty


(CSquire) #5

Just assembled the framework for the drop camera.



(Rusty) #6

Crans,

Looks great. Did you have the HDPE sheet machined or waterjet cut? The smooth edges are very nice.

Best,

Rusty


(CSquire) #7

a local guy cnc routed the HDPE and i finished the edges with a handheld trim router and round bit

thanks

Crans


(Adrian Griffiths) #8

Hi, you are way more advanced than myself. I am trying to hook up my gopro4 to use as a dropcam when we are out diving for wreck/seabed exploration.

So far just trying to get a video feed has proved a challenge. I have now established with both a genuine gopro and alternative cable that I can get the video out. I had a problem in that I was testing it connecting to my CCTV system and only got a black and white picture, as opposed to my CCTV camera giving me a colour picture, so I thought there was a problem with the cable. When the genuine gopro cable also just gave black and white I tried it to the composite connections on the back of my tv and got a colour picture. I then tried it through the yellow composite video connection on my AV reviever connected to my tv and got no picture at all. Most confusing.

I am looking at using a 7" tft monitor for a car reversing camera from fleabay as they are under £20, I don’t imagine they will be up for use in bright sunlight and may have to do the head in the towel shade method.

I have an old dive torch housing that I am thinking of putting it all in, though I do like the look of the bluerobotics tubes.

Alternatively I have a raspberry pi and camera gathering dust somewhere, that might be a less expensive experiment in case of flooding. My goal would be to end up with a controllable rov, so maybe this is the better starting system.


(CSquire) #9

Thats very cool you were able to get the gopro working. What was the solution you used? I would eventually like to use a gopro4 an interface with arduino to the gopro buss connector to allow live composite as well as recorded video feed and still pics from camera in the housing. I figure i can use wifi to download thru housing wall so i don’t have to open up housing to access usb connector for download of files, what do you think, would this work?

thanks


(Adrian Griffiths) #10

I guess that would work but you won’t have a live feed to the surface from the GoPro.

I am just about to order some cat 5 cable, and ordered a car reversing camera monitor from eBay.

Hopefully this time next week I should have the camera system sorted ( yeah like it will be that easy).

next up is sorting the penetration. Not sure about the options. Openrov use an epoxied up slot, which looks easy and does not need a particular shape. These guys use their pentrators, which look really tidy. Alternatively has anyone used cable glands or are these not really suitable for any depth. I am looking to get mine to about 60m, my own diving limit.

at the moment there are several extra connector in the loop but I intend to solder it up, though the picture is good but my cable is only about 2m long.




(Charles Rounds) #11

Try using cat6 shielded cable if you can. At 550mhz+ it should handle the bandwidth of your GoPro much better. Are you going to use any additional lighting as well? At that depth, you won’t have much sunlight.


(Adrian Griffiths) #12

Hi, got the gopro working down 100m of Cat 5e, no baluns and just twisted together ends not even soldered up yet.

Cable out of the gopro is off ebay "Video out and Power in FPV Transmitter Cable Ultra Slim for GoPro Hero 3 3+ & 4 "

Cheapest Cat 5E stranded 24 AWG cable I could find as well

Just awaiting a small 7" car reversing camera screen from amazon and hopefully that’s my basic electronics

Just pondering the penetration into the housing now, pity Bluerobotics are in america

I was going to mount one of my diving lights onto the frame as well, that’s plenty of light for the depths I am going to, though its basically pitch black a lot of the times at those depths around here. I have also picked up a 100w led that I was try to update an old diving torch with.



(John) #13

@Adrian I have used plastic cable glands (see pic) before using epoxy in a similar way as the BR penetrators only difference is I epoxied them in to the housing also.

Regards John



(Ole Hermann Godø) #14

Any idea what pressure these plastic penetrators can handle?
I have never seen anyone test them to the breaking point before.


(John) #15

@ole, in theory as long as there is no void and the epoxy seal around the connector is good they should be good for some depth, I have only been down to about 12m with the ones I have used.

Cheers John



(CSquire) #16

Update to dropcam

subsea is nearly fully assembled and functional, topside and tether next here are a few pics of vehicle

powered up with lights, sensors and cameras

 





(Rusty) #17

Crans,

Awesome! Looks great. How did you make the lights?

-Rusty


(CSquire) #18

the three external lights are made for repurposed ebay off-road led fog lights of this type

http://www.ebay.com/itm/2x-10W-Cree-LED-Work-Light-Flood-Offroad-Driving-Fog-Lamp-Motorcycle-4WD-UTE-SUV-/231692529083?hash=item35f1f36dbb,

the have alum housings and stainless hardware, though are painted and not anodized. i just striped out the led and driver as they were fixed not dimable and installed my own cree COB led then potted with a both a opaque and crystal clear 2 part epoxy resin to seal. the opaque resin i used cures very hard, it is used around the wire entry points. i am considering switching to a more rubber like urethane resin from aeromarine products the reason being that a fellow engineer said the rubber like cable may compress while the epoxy does not and this may cause water intrusion in the resulting gap, what do you think? i know your loctite marine epoxy is pretty hard also but does not seem to be a problem.

 

the internal led is just another large cree COB on a forced cooled heat sink, note an extra fan is installed to circulate internal air against the alum endcap plate just for extra cooling effect.

thats about it. oh i think will be very diligent in washing everything down afterwards with freshwater to minimize corrosion of the alum parts.


(Rusty) #19

Hi Crans,

Very nice. The Aeromarine urethane is good but we’ve had problems with it curing well. We’ve been using Smooth-On products with great success recently. There are also flexible epoxy option such as West System G/flex.

We haven’t had any leaks when using the Loctite marine epoxy but I’m sure it’s possible under extreme compression.

It sounds like you didn’t actually pot the LED in the potting compound? That should be fine as long as the heat makes it into the aluminum shell alright.

-Rusty


(CSquire) #20

Thanks Rusty

Yes, the LEDs are completely potted in clear epoxy