Remotely Operated Vehicles

Homebuilt ROV Group

2010-10-25T14:29:00.000-07:00

As of October 25, 2010, RC Groups now has an ROV Forum. I believe it will be a great resource. Please consider joining (for free) and contributing to the RC Groups ROV Forum.

ROV Forum on RC Groups

2010-08-09T18:01:00.000-07:00

RC Groups is a great site. It has really good search capabilities, numerous thread types, and easy to use navigation.

It would be a great place to have an ROV forum, so I have requested one. In order to become an official forum, the "starter thread" has to have 50 supporters. If you'd like to support the creation of the forum, please become an RC Groups member (it's free) and submit your support for the forum in this thread: ROV Forum Proposal.

Once we have 50 supporters, an RC Groups administrator will create a poll, and if 75% or more voters support the forum it will become official.

Homebuilt ROV Light

2010-07-13T18:45:00.000-07:00

I had added two high intensity LEDs to the relay housing, but the problem I encountered was that they dimmed when a motor was running. This weekend Harbor Freight Tools was giving away LED flashlights for free, so I picked one up. These flashlights fit perfectly in 1" PVC pipe, so I followed the instructions at Homebuilt ROVs and constructed an inexpensive ROV light housing.

The conduit hangers are connected with a small bolt.

Homebuilt ROV Water Tank Dive

2010-07-09T07:57:00.000-07:00

I have made a few changes since the last post due to an electrical problem. The relay control wires shorted out in the wax-potted project box, so I built a new enclosure from PVC and added lighting in the same enclosure.

Below is an excerpt from an underground water storage tank dive.

Update

2010-06-27T10:41:00.000-07:00

I didn't make the test dive deadline I had originally hoped for, but the ROV finally took a test dive in my neighbor's pool.

Here's the update:

The motors I'm using are 8-20V Johnson 9167AK's. I am running them on 12 volts.
The props are freebies as shown here. I have removed two of the blades to reduce amp draw because tests showed one motor (underwater) was drawing well over 10 amps; however, my multimeter is a cheap one that's taken some abuse and may not be very reliable. During the test dive I ran all three motors simultaneously and nothing overheated, nor did the 15 amp in-line fuse blow, so this motor and prop combo seems to be working well despite what the multimeter says.
The prop adapters are from Electrifly, part number GPMQ4600.
Several months ago I wrapped the entire tether in electrical tape, which turned out to be a bad idea. It's not flexible enough, so I am now unwrapping it and only taping it once per foot.
Once the tether work is complete, I'll be ready for another dive. This time I'll take a camera for some above-water footage.

Looking for Motors

2010-01-28T17:42:00.000-08:00

Now that the holidays have passed and spring is only a few short months away, I've begun looking for suitable motors again. I'm open to suggestions if you have a DC motor you've had success using.

My hope is to have the ROV ready for a test dive by the end of February.

ROV Motor Quest

2009-10-05T05:40:00.001-07:00

I've been searching for a cheaper alternative to bilge pump motors, and I haven't found anything yet. If anyone has any suggestions as to what inexpensive, 12 volt, brushed motor would work as an ROV thruster, please let me know. Motors are the only hangup at this point, otherwise the ROV is ready to test.

The props I plan to test I acquired for free from a really nice guy who works for NOAA. He offers instructions for constructing a homebuilt ROV in this document: ROV in a bucket.

Almost Ready to Test

2009-09-15T19:00:00.001-07:00

The controller is ready and tested.

Right now I'm working on stripping off the outer sheath of the phone wire. It's not necessary, but my goal is to reduce the tether's weight and increase the flexibility of it. After that's complete, the tether will be finished (for now) and then it'll be time to mount the thrusters and begin wet testing. Bear with me... a test dive is on its way soon.

ROV Construction Updates

2009-09-10T00:05:00.000-07:00

Camera Housing

I was concerned about the area where the video cable exits the camera housing because the epoxy didn't seem to bond to the wire, so to calm my fears I epoxied a 1/2" cap in place and filled it with adhesive silicone.

Skids

The unsealed landing skids are 15" long 1/2" PVC with re-bar in them for weight. One end cap of each skid is glued in place, and the other is just pushed on tightly so that I can have access to cut the re-bar down to size if necessary. Right now the re-bar runs the full length of each skid.

Power Hub

I want one connection to the battery and one central spot to connect power to everything else, so I used this small project box, two sets of banana plug/multi connectors, a female coaxial size M DC power plug, and a male size M DC power plug to make this. One banana plug set is for the inverter to run the TV, the other set is to power the ROV. The female power plug goes to the joystick controller, and the male plug is to power the ROV's camera.

Controller

Here's what I have so far on the controller. I used a D-sub connector to attach all the control wires, but I wouldn't recommend using this type of connector. It's small and hard to solder, so I'd suggest using something larger and easier to connect. The green light is just a power indicator.

The control box is wired (wiring isn't complete in this photo) exactly as described in the How-To ---> Relay Wiring for the Electronically Challenged ---> "H" Bridge Relay ---> Joystick and Controller Wiring section of Homebuilt ROVs. I would link directly to it, but I don't know how because the site has frames.

Update Coming Soon

2009-09-09T04:25:00.000-07:00

I've been too busy working on the ROV to post an update lately, but there's one coming soon.

Control Box

2009-09-05T08:13:00.000-07:00

Here's the Potter and Brumfield door lock relays I'm using for the thrusters.
Let's call the coil on the left of the diagram Coil 1 and the one on the right Coil 2. Here's how they're wired:
F: Control wire for Coil 1
E: To thruster motor
D: Common positive for load and common positive for Coil 1 and 2
C: Negative for load
B: To thruster motor
A: Control wire for Coil 2
If you need more relay help, I'd suggest looking at the How-To section of Homebuilt ROVs, or you can ask me and I'll try to help.

The relay on the left is unaltered, and you can see that I've cut the prong cover off of the relay on the right to allow access for soldering. The assembly inside comes out of the case easily so that you can modify the case however you want to. I accidentally cut too deeply into the case on one of the relays and didn't seal the hole well enough before I potted the control box in wax. More on that below...

Update, 04/17/11: You can read more below on potting your controls if you're dead set on doing so, but my advice now (from experience) is to build a watertight enclosure to house the electronics rather than potting them. The benefits are that you can access them easily for future modification, and it's less likely to leak. Just my two cents.

Here's everything all wired up and in the project box (from Radioshack). The relays are covered with electrical tape to hold them together for soldering the connections and to hopefully seal them from the wax.

I used white table candles from the dollar store and melted the wax in this disposable pan using a double boiler to keep things from getting too hot. Melting wax can be dangerous, and I don't suggest doing it without researching how to do it safely first.
When I poured the wax I saw air bubbles coming from the area around the relay that I accidentally cut. As it turns out I didn't seal the hole well enough and wax got into the case.

There are 6 relays in the box; 4 are Potter and Brumfield door lock relays (intended for the thrusters, 3 now and 1 later), and there are two regular SPDT relays for what I had hoped to be a two-stage lighting control. The fourth relay from the left is dead due to wax leaking into the case. I'm not going to reopen the control box and dig the wax out for one relay, so I'm thinking I'll just do without the fourth thruster for now. I can use the two SPDT relays for another thruster if I choose to do so in the future, and then I could add another small control box for lighting.

The original plan was to only have three thrusters anyway, so I'm not too upset over the mistake. Just be warned: Be sure you your relays are well sealed before potting them.

Frame and Camera Update and Relay Testing

2009-08-30T19:32:00.000-07:00

The frame is glued together, and the milk crate bottom is now attached with zip ties. Thanks, Dennis M., for the free milk crate.

I submerged the camera housing for a couple hours to check for leaks, and everything looked good. The camera is held in place with velcro and a short piece of pool noodle.

A friend (and electrician) at work helped me figure out how to hook up the relays. I tested them last night and began soldering things together for the control box, so I'll post pictures of how that goes together soon. My control box won't be any different than Steve's at Homebuilt ROVs, but the relays I'm using are a different brand and type (Potter and Brumfield) so I think it might be helpful to show the wiring for anyone else who might use them.

ROV Frame

2009-08-29T07:18:00.000-07:00

Here's the frame, which is made of 1/2" Schedule 40 PVC. I ended up going for the ROV-in-a-box design.

The frame is all ready to either be glued or screwed together. I'm weighing those options, and I'm leaning towards gluing it together because I'm trying to make the ROV as light as possible, and if the frame is sealed it will add to its buoyancy. The only benefit of screwing it together is that it would make mounting things to it easier since I could drill all the mounting holes I want. Feel free to give your input as to which option you think is better.

The horizontal pieces are 5" (12.7cm) each, so with the tees and elbows the frame is about 12.5" (31.75cm) wide.
The upright pieces are 6.5" (16.5cm) long, and I didn't record the measurements for the small pieces of the uprights that have tees, and those required some trial and error anyhow.

A cheap PVC cutter and a rubber mallet make dry fitting easy.

ROV Camera Housing

2009-08-27T18:07:00.001-07:00

This first picture shows the 2" PVC cap right before I epoxied the wires in place from the outside. The blue material you see inside the cap is modeling clay that I used to keep the epoxy in place until it set. That turned out to be a bad idea because it was difficult to remove the clay afterwards. I think some tape on the inside of the cap would've been better. The audio connector will not be used, at least not for now, so it's covered in electrical tape to keep me from hooking things up wrong.

The epoxy is now in place on the inside of the cap. The blue tint is from the modeling clay residue, but I don't think it will cause any problems since it's just a stain. I sanded the cap around the wire exit hole inside and out to give the epoxy something to bite onto.

Here's the rest of the camera housing. I'll glue the end cap on tomorrow after the epoxy has fully cured at the wire exit.
The extra connector you see coming from the PC302XS is an RCA cable that I soldered on in place of the stock connector so that it mates up with the connectors on the video cable extension.

Help Name The Nature Conservancy's ROV

2009-08-27T06:36:00.000-07:00

The Nature Conservancy has a new ROV. If you'd like to help name it, cast your vote before August 31st.

ROV Parts - Part 3

2009-08-22T18:39:00.000-07:00

Aside from the control (phone) wire, I've ordered most of the control hardware from All Electronics. I wanted to order the same relays that Homebuilt ROV's uses, but Electronics Goldmine didn't have the joystick I was looking for, and I wanted to consolidate my order from one supplier to save on shipping. I hope everything I've ordered fits my needs. Here's what's on it's way:

-(1) 8-way Joystick
-(2) Momentary Toggle Switches
-(1) Non-momentary Toggles
-(4) Door Lock Relays These are supposed to be an H-bridge configuration, but don't take my word for it until I receive and test them.
-(2) 12 volt SPDT relays for lighting controls

*On another topic... I've started working on the camera housing, and will post pics soon. Sorry for the delay in adding pics of anything.

ROV Parts - Part 2

2009-08-18T18:26:00.000-07:00

For the tether, I'm using 100' of 16 gauge speaker wire, 2 sets of 6 conductor phone wire, and a Q-see 120' RCA video cable extension. These items were all purchased from Walmart; however, I did have to site-to-store the speaker wire and video cable.

ROV Parts - Part 1

2009-08-17T17:52:00.000-07:00

The camera I'm going to use is the PC302XS black and white board camera from Supercircuits. I picked this model primarily for two reasons, the low price and light sensitivity of 0.01 lux. The housing for it will be constructed from a 2" union, made following the instructions in the How-To section of Homebuilt ROVs.

ROV Goals

2009-08-16T08:21:00.000-07:00

I'm not exactly sure yet what my final design will be, but I plan to base this ROV project somewhat on the popular Seafox and/or the ROV in a box design. I'm buying all the parts before I settle on the frame design.

The initial project design is as follows:

-3 axis movement via 3 thrusters (up and down, left and right, forward and reverse)
-Joystick control panel
-Onboard B&W board camera
-Switched lighting system
-100' tether

About Remotely Operated Vehicles

2009-08-15T19:32:00.000-07:00

Photography and gadgets have always appealed to me. In 2007 some friends helped me learn to fly model airplanes, so that experience gave me the opportunity to merge my interests in gadgets and photography into aerial photography. In late 2009 I decided to build an ROV after watching a diver's video feed during a water tank inspection at work. There's something about being able to obtain images and video from hard to reach places that thrills me, so an ROV opens up a new host of possibilities to do so since I work for a water treatment utility.

There are many sites with lots of great information about ROV's, and the one that I have referred to the most is Homebuilt ROVs.
I hope my site will be as helpful to someone else as Steve's has been to me.

The "ROV-in-a-box" frame design is what I used for my first ROV, although I did not purchase the kit. If you want to get up and running quickly with your own ROV, I would highly recommend buying the kit.

Thanks for visiting. Please leave comments and come back soon.

Disclaimer: Take any advice or guidance you find here at your own risk.

What's an ROV?

2009-08-14T18:54:00.000-07:00

Wikipedia has a great definition: ROV.

E-mail

2009-08-06T20:03:00.000-07:00