Final Presentation

I realize I've skipped a few steps since the last update, but now that our ME 191 senior project presentation is over I'll try to post some additional material over the next few weeks. Hopefully it will be of interest to those following our project and a help to other students building ROVs.

To start with, you can download our ME 191 presentation*. The introduction is nearly identical to last semester's presentation, but there's a lot of new material after that. In particular you'll want to watch our three ROV videos and our commercial. I've also uploaded higher quality versions of these videos separate from the presentation. The file sizes are the same for the Quicktime and Windows Media versions because I used the same data rate. (Edit: They are also available on YouTube, but in lower quality since I uploaded them in 2008 before HD was available.)

In summary: The ROV works very well, and it has been a lot of fun. Although the class is almost over, we're not quite done with the project. At the end of next month we're planning to take the ROV to Lake Tahoe for a serious test.

*The presentation was built using Flash, so you'll need to download it, uncompress the files to a folder, and run the executable to launch it. Since I only have a Windows XP computer I'm not sure if this will work on a Mac. I included the SWF file that the executable was built from so you may be able to run that directly.

First Pool Test

We did our first pool test today! It worked! We're not done -- there are still many things to do over the next couple weeks -- but our initial test was a success. Most importantly, there were no leaks. We need to make a few tweaks to the control system, but it was still really fun to pilot our ROV. It's a good thing I had to get to class and Jacob had other commitments or else we could have spent the entire day running the ROV around the pool.

Download a 2 minute video if you'd like to see how it worked. The ROV camera wasn't hooked up yet (it will be for the next test, probably on Monday) so this is video taken from the my handheld camera.

Pool Test 1 - Quicktime (11.5 MB)
Pool Test 1 - Windows Media (14.5 MB)

It Floats!

Jacob and I put the ROV in the pool for the first time tonight (without electronics or power). We probably should have waited for Derek, but he was studying for the E.I.T. exam and we were just too anxious to see what would happen.

Anyway, we're excited that the ROV floats! Obviously we really need it to be neutrally buoyant, but we still have electronics, cabling, and the fairing to add. It's easier to add weight then to add buoyancy. There were many unknown weights/volumes when we designed the ROV last semester, so it was impossible to make perfect buoyancy calculations.

I haven't been very good about posting pictures to the blog the last few weeks, but we've been taking pictures and I'm working on a very long and detailed post about what has been our #1 problem for the last month and a half: sealing the cabling going and out of the electronics housings.

Lights From Carrillo Underwater Systems


We'd like to thank Carrillo Underwater Systems for their generous donation of two C-Lites! They just arrived today and we haven't had a chance to try them yet, but I think this is the last major component we need. Now we just need to finish putting things together and seal the cables going in and out of our electronics housings (currently our #1 issue).

The Tether Is Here

100 feet of tether from ProtaCraft just showed up this morning! It'll probably be a couple weeks until we're able to do our first pool test, but prior to that I'm sure Jacob is going to want to put the tether in the pool to test its neutral buoyancy. We can also hook up our power supply and test for voltage drop. Voltage drop calculators haven't been too helpful (they all produce different results) so we're hoping the voltage drop isn't too bad. Our power supply (a Mean Well SP-750) is adjustable from about 21 volts to 31 volts, and we only need about 20 volts, so hopefully this is enough range to compensate for the resistance of the 14 gauge power cables in the tether.

To-Do List

Last night Jacob and I made a list of things we need to do, and things we still need to buy. Derek couldn't meet last night, so we wanted to email him a copy of the list. I ended up taking a picture of the list and sending that, because unfortunately I don't have a scanner right now. My last printer/copier/scanner broke, so rather than replace it with another multifunction device (and be out all three functions if it breaks) I bought an HP LaserJet for fast and reliable printing (so far, so good) and now I just need a new standalone scanner. However, it seems like everyone is buying the multifunction devices so standalone scanners have actually gone up in price!

Anyway, back to the list, we have lots of little to-do items. We have some things to research, some parts to drill and tap, and various miscellaneous items to buy. A rough estimate indicates that we can complete the ROV for about $850 more. The biggest unknown however, is the fairing. We figured we would put the fairing off until later in the semester -- but now is later in the semester so we need to get working on this.


I just added some sponsor logos on the left sidebar. We've been fortunate to receive discounts and financial help from several places. If you're in the market for ROVs or ROV parts be sure to check out SeaBotix and ProtaCraft. We got our thrusters from SeaBotix at a nice discount, and our tether and video baluns (used to transmit video over the tether) are in the mail from ProtaCraft.

Big Purchases

Today was a big (translate: expensive) day for ROV purchases. We ordered our camera and tether. We ended up spending over $300 on the camera (about three times what we originally budgeted), but we decided that the camera wasn't something to cut costs on. Hopefully it pays off and we'll have some decent video to post online later this spring.

The tether purchase is also very exciting. We were going to purchase individual cables rated for underwater use, bundle them together, and attach flotation devices to make the tether neutrally buoyant. However, last Friday I stumbled onto a manufacturer that sells neutrally bouyant ROV tether for a reasonable price. We ordered 100 feet, which is a lot more than we need for the MATE competition but it will give us greater ability to explore the local lakes.


I'm pretty sure this is NOT the right way to install an O-ring. Fortunately we have extras. Now that we have our polycarbonate tubes and aluminum end caps (for our electronics housings and camera housing) all the major mechanical fabrication is done (besides the fairing). Now we need to take care of lots of other things, such as mounting the electronics in the housings, buying the tether, camera, and lights and making our own underwater connectors (using hose barbs and epoxy).

Engineering Expo

Our Table at the Engineering ExpoOur Table at the Engineering Expo

I'm a week-and-a-half late on posting this entry, but better late than never. The Engineering Expo on Feb 18th was a big success. Lots of people came by and talked to us. Most were very interested in what we're doing. There were a lot of families there, so hopefully we inspired a few kids. We let people move the joystick and watch the thrusters respond, but there was one annoying kid who grabbed the joystick and slammed it back and forth without even looking at the thrusters! Some kids need a good spanking. Fortunately most were well behaved.

There was also one adult worth mentioning. At first he seemed really interested, but then he asked if the ROV would be radio controlled or tethered and after we explained why all ROVs are tethered (radio frequencies don't penetrate water very well) he exclaimed, "What a stupid design!" and walked off.

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