Jun 20, 2012, 05:53 AM Registered User Joined Jun 2012 2 Posts Designing first ROV - Need some help Hello everyone! I recently got interested in ROV's and decided to build my own. I am looking to capture some images of wildlife under the surface and perhaps find some kinds of treasures like old boots and empty beer cans.... I am currently working on the design, trying to make a calculation of costs and figuring out how to build it. But i can't get anywhere until I know what kind of engine I need. My first thought was to make it about three feet long and beeing able to carry about 150 pounds carrying a 100ah battery, but I decided to scale it down. The ROV will be equipped with at least two xenon-lamps and at least two cameras. One full HD for recording and one for FPV. This means that it needs to be quite large. I am looking to place the engine in a tunnel that goes right through the ROV. So here is my questions: - What kind of motor/prop combo do I need to move a ROV that weighs 20 pounds? - What kind of motor/prop combo do I need to move a ROV that weighs 30 pounds? - What kind of motor/prop combo do I need to move a ROV that weighs 60 pounds? - What kind of motor/prop combo do I need to move a ROV that weighs 100 pounds? I am looking to shape it a bit like a submarine. I will most likely run it at 12V. The number I need to know is the amount of watts needed to get this thing moving, so I can start calculating on what type of battery I need. This will have a huge impact on the build. A system for diving will be implented so speed does not have to be more than 2-3mph. Best Regards
 Jun 20, 2012, 06:25 AM R.O.V. Man Devon UK Joined Jan 2006 351 Posts Hi. And welcome to the forum. You need to tell us the conditions that you will be flying in IE tide speed and Max depth. Also your budget and the time span for building. Also your approx location as this can affect were you are able to purchase items. What kit ( hand tools / machine tools you have access to). Quote "I am looking to place the engine in a tunnel that goes right through the ROV". Do us a little drawing. As for the motor size... There is a thread somewhere in this forum to read. Also what is the material you are building with. A shape like a Submarine will not have good turning capability. It looks you are set upon having the power source bottomside ..Any reason?? Regards Antony
Jun 20, 2012, 06:58 AM
Registered User
Joined Jun 2012
2 Posts
Quote:
 Originally Posted by hargard Hi. And welcome to the forum. You need to tell us the conditions that you will be flying in IE tide speed and Max depth. Also your budget and the time span for building. Also your approx location as this can affect were you are able to purchase items. What kit ( hand tools / machine tools you have access to). Quote "I am looking to place the engine in a tunnel that goes right through the ROV". Do us a little drawing. As for the motor size... There is a thread somewhere in this forum to read. Also what is the material you are building with. A shape like a Submarine will not have good turning capability. It looks you are set upon having the power source bottomside ..Any reason?? Regards Antony
Thank you,

I will use the ROV in small lakes to start with. So there will not be any tide to talk about. I might be using it in a river nearby in the future, which is running at two knots.

I have no set budget. I wan't to make ite as cheap as possible. Somewhere around 500\$ to get started with, adding cameras and lights later. But still want to have it prepared for that to make my life easier later on.

Living in sweden. I am currently running a company which repairs autos/trucks/busses. That means I have pretty much infinite resources when it comes to fiberglass and metalls which will be used to build the hull. Also, a ton of tools to use. From what I have read, HobbyKing is the #1 place to order servos, motors and other components.

I figured a three piece design. Think of three pipes fit togehter in a triangle. The bottom one will have a hull shaped like on a boat and contain components and electronics. The upper two pipes will be containing air and lights. I am looking to make the density of the ROV to match the waters and then place a small motor on top to help it dive.
I also thought that putting the main engine on top of the bottom pipe would be a good idea, sucking water from the front of the ROV and pushing it out at the back. Will return with some drawings later, quite hard to explain.

I want to be able to control the ROV from land, having it go 100 feet out in the lake and 20-30 feet down. I thought about placing an antenna for the reciever in a box that floats and is connected to the ROV. If I put the power-supply on land, I would need to have a lot of cables running down the water, possibly getting stuck and tangled.
Jun 20, 2012, 04:33 PM
R.O.V. Man
Devon UK
Joined Jan 2006
351 Posts
Hi.
This I gotta see.
Quote:
 Originally Posted by Nenivraj I figured a three piece design. Think of three pipes fit togehter in a triangle. The bottom one will have a hull shaped like on a boat and contain components and electronics. The upper two pipes will be containing air and lights..
Sounds inventive
This has been done and works well "sucking water from the front of the ROV and pushing it out at the back." Google AC-Rov. Its very small . Found it difficult to handle at first but you get used to it. This one has a through thruster on each corner.
The umbilical cable is the hobby RoV's pain in the neck.. No easy answer to this one.
My Mk1 RoV had 2 pair twisted wires and a small airline to the RoV.
I used a Radio control with a extended antenna to the surface like you are planning. And yes my battery’s were bottomside.
If you can do a simple sketch we will be better able to advise on motor watts.
Regards Antony
Last edited by hargard; Jun 21, 2012 at 03:40 AM. Reason: More info