Poseidon Mk II

[AHarris]

Hello HomebuiltROVs,

It is me again, two failed ROVs and a bit short in the pocket. Since attempting to build ROSEV, and Poseidon (MK1), I have returned with a bit more maturity, saved up money (pushing £200 GBP ($302 USD) if necessary) and a new plan!

Poseidon MkII

The second generation Poseidon is a follow on design from the original, which I got surprisingly far with, but even that unfortunately failed.
The design essentially is a metal frame, with a buoyancy device on top. Within this you have three motors to drive the ROV, a set of relays and a camera. These electronics are distributed along two boxes, which are likely to be filled with either oil, or potting compound to keep out water and help provide a balance against pressure.

My plans to prevent this one from ending up like the last set, thorough planning and a full technical document. I've managed to source all the parts, but now it is up to me to do a full set of calculations, especially considering it shall be ocean going so I need to contend with salt water and strong currents.

Until then, here are some images of the proposed design:

[Tal]

Hello mate,

Looks great! and look forward to seeing how your project works out along the way. I'm only relatively new to the forum so I'll have to track down your other projects and see what happened

[AHarris]

Thanks for the support Tal,

Unfortunately my previous designs failed, mainly due to a lack of supplies and a dwindling budget. Living on a tiny island, I can only source parts from mainland England which makes it very expensive to buy, and to ship.
As a result of this, unfortunately parts which I would of preferably wanted had to be missed, and I had to make do with a limited selection which left the build with some flaws.

[thegadgetguy]

Welcome back AHarris - good luck on your ROV!

[AHarris]

Thanks thegadgetguy,

It's good to be back!

[Tal]

Yes AHarris,

I can relate to your previous budget issues! I've started working on my first ROV a couple of months ago, and while the progress is steady, its slow going. Along with being my first ROV, its also my first complex project like this at all as I'm new to pretty much anything to do with this which has also lead to discovering my poor workshop is making things even harder. So my budget is now being stretched to include new tools and machinery, along the way, that I'll need or would make a big improvement to the workmanship. This hasn't halted the project, but just slowed it right down

I found your Poseidon MKI and see you're following a similar approach, which would help you heaps this time around You'd have most of the hardware already, from previous attempts? What software did you use for your plans? Looks great!

[AHarris]

Yep, I thought it would be best to follow a similar design as I know this one almost worked, and I can simply correct the problems I had before I begin the build.

The software I used to make the drawings is Trimble Sketchup (formerly known as Google Sketchup), although my CAD skills aren't the best. The metal frame is supposed to be tubular instead of box cut, however my attempts at drawing it where truly appalling. The dimensions should however be accurate.

[KR2_Diving]

The metal frame is supposed to be tubular instead of box cut, however my attempts at drawing it where truly appalling.

I feel your pain! I tried the same thing, and in the end, I just went back to 2D and paper drawings!

[AHarris]

Ok, I think I have pulled together a parts list.

Metal Tubing - 2.24M
90 Deg Elbow Connector - 4
3 Way Connector - 4
Swimming Float - 1
Bilge Pump - 3
Prop (Computer Blade) -3
DPDT Relay - 6
Reversing Camera - 1
Momentary Flip Switch - 3
60 Ml Syringe - 1
Project Box -2
Project Box (Clear Lid) - 1
Potting Compound/Mineral Oil - 5L*
Cable Ties - 35*
Cat5 Cable - 25M
Pipe Insulating Foam - 2M
RCA Cable - 30M
Two Core Power Cable - 26M
12V, 12Ah Gel Battery - 1

* = Approximate Value


I can't think of anything else that I would need, although if anyone spots anything which is clearly missing I would appreciate it if you pointed it out to me!

Now to attempt drawing a set of step by step diagrams for assembly, hopefully now I will see if I miss anything.

[scubersteve]

Perhaps I'm looking at it wrong, but do you have openings in your top plate so the vertical thruster can move water vertically?

Just curious.

In what way have your previous designs failed?