Poseidon - ROV Project

[AHarris]

I am currently working on Poseidon, which you may know as being the Greek God of water, and which is the name of my ROV (fourth attempt).
I just wanted to list the specifications and the plan to see what you lot think of the idea, and hopefully help me pick out any potential issues.

The ROV shall be a basic level ROV which is capable of doing shallow dives (2m to 3m) in open salt water. The ROV shall have a colour camera which shall be connected to a control station and laptop on the surface.

The Frame
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The frame shall be of a solid box design, with a single wire entry/exit hole. It most likely shall be made out of ABS plastic and possibly wax filled depending on the size.
There shall be a main thruster on the top for up and down movement and two on the back for forward and turning, these shall be made from modified bilge pump motors.
The front shall have lights and camera 'port holes' to allow a live video feed to the surface.
The top of the ROV shall have solid foam attached to it to allow for additional floatation. In total, I am expecting the ROV to be about 240mm X 160mm X 120mm with the foam blocks.

The Electronics
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As I mentioned earlier, the thrusters shall be modified bilge pumps with computer fans attached (cheap solution to model boat props) and shall be about 80mm in diameter (may change depending on amp draw).
The ROV shall have onboard batteries which if my understanding is correct shall reduce voltage drop?
This then shall go along a Cat5 cable to the surface where I shall have the control station.
The camera shall be a small, colour bird box camera which shall have an RCA cable which can connect to an EasyCap and a laptop. The camera shall be assisted with a set of lights which I still need to decide on.

The Control Station
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The control station shall be a basic, entry level control station. The control box shall be a set of momentary flip switch providing forward and reverse for the three thrusters.
The laptop shall provide a live video feed and shall also act as the recording device for the dives.



That is about it, please leave comments, suggestions and tips so I can further improve the design!
Thanks

(P.S. I'm not the best artist, but hopefully this shall give you some idea as to the design)

[ltdcruze]

I like it. Although with an on-board battery, you might want to consider a way to easily access it. I would suggest maybe a waterproof toolkit. They sell them at Academy in various sizes. All you would have to do is drill a hole on one side and either epoxy that hole with the wires in it, or make a removable tether with a PVC coupling and an 0-ring. Also, how are you going to make a "solid-block" design? This sounds quite heavy and expensive. Don't take it negatively, but these are all things to consider before you waste time and money on things that don't work. Unfortunately, I have learned that the hard way.

[AHarris]

I'm not taking it the wrong way, infact I am glad you have picked this out!
I too have learnt the hard way, but fortunately I am able to recycle the old motors e.t.c. into the new ROV.

The solid block design idea is coming from a set of ABS Plastic watertight enclosures which I have found online:

http://www.rapidonline.com/Tools-Equipm ... ures-Boxes

I have changed the design a bit from what can be seen in that example and I am now going for a more open top and bottom sort of thing, hard to explain.
Basically, I am now having a solid top and a solid bottom with a space in between, the top being for buoyancy and the bottom being for weight.
Theoretically, if the boxes hold up to an approximate 3M pressure then I shall be spending about £60. I however still am jiggling the design around a bit but thanks for picking this up and I shall look into it.

As for the onboard batteries, what I have now decided to do is have the batteries up top and insert a set of relays in the ROV. This means it is easy access and the ROV is less bulky.

[ltdcruze]

Okay. Sounds good. You might want to consider a joystick or something for control.

[AHarris]

Thanks, in some of my previous failed attempts I did have one although my soldering isn't the best so at the moment I just want to go for something with big pins which I can secure the cables to.

But it is certainly something I shall look into when I upgrade, but as I say, at the moment I just want to get something which works

[AHarris]

Ok, I have got some additional work done on the design and attached is some concept work.

-The yellow blocks on the design are your ordinary swimming floats, nothing expensive but the hard foam block design as oppossed to the squidgy sort of ones.
These shall act as floatation and are positioned on the top and on the back (heaviest part although weight distribution may change).
They also act as supports for the bulk of the equipement and I am planning on cutting holes into the floats to allow for ABS boxes to slot in.

-The motors are bilge pumps (can't remember the type) and I have attached some computer fans onto them which should provide more than enough thrust.

-The box on the front is the camera compartement, which I am thinking of filling with a clear resin to create a solid block around the camera to allow for deep diving (although need to check whether the camera would work with this).

-The black box at the back shall hold the relays and also shall be where the tether goes in and the motor wires join e.t.c.
I shall probably do a similar thing to this as the camera box, fill it with potting compound for strength.

-The frame shall be made out of aluminium pipe which I can easily pick up from my gardening store, and it is light weight and strong.


Hopefully, the floats shall not warp as much and should be fine at relatively deep depths and the solid blocks of resin should not be damaged by the pressure.


As always, suggestions and tips are appreciated!

[ltdcruze]

Computer fan blades might draw quite a few amps. I find RC boat props work best.

[Silver dollar]

Is the yellow block under the aft thrusters for boyancy? I would place it on top instead. The ROV might flip around if you have it as it is now or it can be unstable.

[AHarris]

Thanks for the advice guys, it was originally planned for buoyancy but considering your point I may change it depending on how the weight is distributed.

Equally, I shall do some additional tests on the computer fan blades and see what sort of amps they draw.

[derelicte]

you also want the buoyancy more of less evenly distributed otherwise it won't float level.