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New build started


(Richard) #1

I have started building and testing my project so I am moving my posts to the “Build” section.

Project goals are a 130 ft capable ROV with 4 thrusters and an onboard CCTV system for live underwater video photograpy of marine life on the artificial reefs off jacksonville, Florida (that was a mouthful).

I am already doing video work on the reefs using drop-down tethered GoPro cameras. See my youtube channel Richard Fast.

Phase 1 is a drop-down tethered CCTV system with no thrusters. This will fully test out the CCTV circuitry, cat5e tether and water-tight enclosure in the ocean environment.

Phase 2 will add 2 thrusters for 2-dimension control.

Phase 3 will add 2 more thrusters, giving 3-dimension control.

Total project cost goal is less than 1000 dollars.

The ROV I am building is a hobby/recreational project. It will never be used for commercial work and certainly doesn’t need to be mil-spec. There will be failures, but nothing dramatic, or too costly, because I have diver friends who frequent these reefs who will help me out recovering broken pieces.

The number one problem this project faces is current! On our reefs it rarely stops, and typically runs more than a knot of velocity. Those of you dreaming to build an ocean ROV need to get out on the water in 3 foot waves and see what it is like to try and control something moving around on the bottom in a 1 knot current. It is a world apart from a lake or swimming pool.

Here are a few pictures showing the topside control box, tether cabling, and ROV control board. The watertight enclosure will be a 4" ID tube, 8 " long, with 1/2" plexiglass end plates (see pictures in my other threads). The live video of my car you are seeing on the monitor is through 200 ft of cat5e cable. You can also see the impedence matching baluns, which don’t seem to be necessary, but I am using them because the theory says I should.

Please feel free to ask questions.

Thanks,

Richard

 

 

 

 





(Rusty) #2

Richard,

Thanks for posting. I look forward to following along.

Rusty


(Harold Scadden) #3

@Richard - how do you plan on sealing the ends of your container? Are you using one of the enclosures from Blue Robotics or a homemade one?

Speaking of current, have you ever given any thought of putting a current speed sensor on the unit and maybe have that control the thrusters so the device could hover on site? You could consider it kinda of a basis signal in addition to whatever you are sending down to it. Just a crazy thought.

 


(Richard) #4

@Harold-I am using a homemade enclosure for now (PVC pipe), and will shift to the Blue Robotics for the final build. End plates are 1/2" plexiglass. One end is epoxied to the tube, the other end is a flanged enclosure using a 1/8" rubber gasket for sealing. See the picture below, which has the flange glued on but the endplates are not installed.



(Richard) #5

Initial watertightness, and weight and balance testing was conducted today (in ye old garbage can). TV camera is up and running great also. Weight pods are just taped on to allow for adjustment before they get the final fix epoxy treatment. Turns out they are in the correct location. Neutral buoyancy is right at 4 pounds added lead in the pods. Screw on access plug at the back is a test piece (no hole through back plate yet). If it proves watertight at depth I will drill through the back plate and use it for accessing power line connectors, instead of a remote operated switch, which I am uncomfortable with. A couple of pictures are attached.




(Richard) #6

Ready for at-sea testing. This completes phase one (CCTV). I’ll order the T100’s when I save up the funds.

 







(TCIII) #7

Hi Richard,

I live down in Ft. Lauderdale and have been working on a 6 thruster, 2 WTC ROV using BR components.

I will be using onboard LiPo batteries to power the ROV.

I am at the point of setting up the BlueESC thrusters for I2C control.

I am waiting on the delivery of a custom tether and navigation shield to complete my ROV.

You can follow my build here

Regards,

TCIII AVD


(Richard) #8

@TCIII AVD - Our approaches are certainly different, both cost and compexity wise. If you have access to a boat just do your leak testing in a real environment. As you have found out, vacuum testing will drive you crazy. Don’t put any control or power source components inside the tubes except the cable ends and drop it over the side in 10 foot increments (pull it back up and check for leaks after each increment). That way you can fully test down to where you intend to operate and you can see where the leak is coming from. You will also see the effect of current on your design. Even a garbage can is a good starting point! I have a few questions:

What motor LiPo capacity are you going to use?

How do you intend to switch the power on and off?

How will you recharge your power source?

What camera setup are you going to use and what about the topside monitor and recording device?

Good luck, it is a challenge, but well worth it.

Richard


(TCIII) #9

Hi Richard,

The LiPo capacity is two 5000mah LiPos in parallel.

The LiPos are in their own WTC where I can pull the end cap off to remove them for recharging and to plug them into the Battery Junction Board to supply the 6 Thrusters.

I will use a GoPro 3+ Silver mounted in an Eye of Mine Waterpoof case that has a waterproof SD feed that will be sent up the ROV tether over a twisted pair for viewing on a laptop control/display. The GoPro will also be recording in HD on the internal SD card for viewing at a later time.

Based on information the Video Ray user manual, I suspect that the vacuum testing will give me a reasonable idea as to any potential sources of leaks at the ROVs operating depth.

Regards,

TCIII AVD


(Richard) #10

I like the idea of the internal GoPro camera with an SD feed to the surface. The Eye of Mine web site is a good find, thanks. Where did you source the tether cable? You and I both plan on two 5000 LipO’s for power. I don’t know about you but I am a little concerned that may not be enough capacity. On a typical trip to the reefs I want to bring back a couple of hours of video to edit. Depending on the current, I am hoping 30 watts average with the 4 motors will do it. I won’t have room for a third battery pack in my 4" x 8" WTC. My camera and control board electronics (Basic Stamp) are powered from the surface through the tether. I draw 250 ma from a 2250 LiPo pack in the topside control box. The monitor has a built in battery pack good for ten hours. I am going to Key Largo on a dive trip this Friday and I will be taking my build with me for first tests down to 100 feet. It is not yet an ROV, just a tethered CCTV system, but it is the foundation for what I want to accomplish. Good luck and let’s stay in touch on our progress.


(TCIII) #11

Hi Richard,

Since the GoPro has its own battery the LiPos just have to power the Thrusters and the Navigation Controller so far. Adding lights or a gripper will add an additional load on the batteries.

Since ROVs are really not meant to be fast, I am hoping to get about an hour’s worth of time out of the two LiPos.

The tether is experimental and the developer has asked me to wait about revealing my source until the beta trials are completed in case there are any complications that need to be addressed.

Where at Key Largo will you be operating? John Pennekamp State Park is a good place to try out an ROV if you can get reservations.

Personally I like Jensen’s Landing at the north end of Captiva Island.

Yes, lets stay in touch and share what we learn with our ROV projects.

Regards,

TCIII AVD


(Richard) #12

We’re staying at the Amoray dive resort and taking a boat out to the state park on Saturday and Sunday. Where do you stand on selecting a monitor that has good bright light performance? This has been a problem for me in the past. I hate having to put on a hood with the boat rolling around.


(TCIII) #13

Hi Richard,

Good LCD monitors with anti-glare screens built-in are relatively expensive from what I can find by searching on the web.

I have seen a number of outdoor monitors with hoods as that is the inexpensive approach.

I have an addon anti-glare screen for my Samsung Galaxy Tab2 10.1 tablet that works somewhat, but still leaves a lot to be desired.

This is something that needs further research if I am to use a laptop for control and/or camera display.

Regards,

TCIII AVD


(Richard) #14

This is what I am currently trying:

http://www.ebay.com/itm/281482481599?_trksid=p2060353.m2748.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It also leaves a lot to be desired but is okay for prototyping. I wonder if the monitors made for camera drones are geared more for outdoor use? That may be a less expensive solution.

I have dropped GoPro’s down and recorded video, and then when on the surface I have downloaded to my iphone using wifi. The iphone is almost unuseable for video viewing with detail in bright light. Solution is to cover my head and phone with a towel. Not what I want to do.

 


(Richard) #15

I am continuing to test the durability of the cat5e tether. Going well so far. I really try and treat it just like a piece of rope. Here is a couple of videos from my trip Wednesday. Once I get the thrusters I can nose into those caves. Guarantee there are grouper in there.

Richard

 


(Richard) #16

Oh, and by the way, make sure your ROV is rugged enough to handle this ( a fairly common occurance):


(TCIII) #17

@Richard,

Take a look at the video in this Shark versus AUV article from Hackaday.

Regards,

TCIII


(Richard) #18

Oh my gosh, that is fantastic stuff! Thanks.


(Richard) #19

Well, I just pulled the trigger: two T100’s and ESC’s ordered!


(Richard) #20

Yeah! My T100’s just arrived. Tomorrow is going to be exciting… but not as exciting as watching the SpaceX first stage land back at Canaveral. What an incredible accomplishment.