Maine Island PerspectivesJanuary 17 2017
My daughters (9) & (7) and I are in the early planning stages of a project to document the transition zone from ocean bottom to the rise of islands of Casco Bay, Maine using an OpenRov 2.8 that we will (hopefully) build together this winter.Read background
You are set up to receive WePay payments.
Here are the details to your account:
Name: Brooke Mohnkern
Account ID: 944511371
The Kraken performed well this past weekend-- Most successful dive yet!
I have a lot to learn about video post production I admit. But, I was eager to get footage of our dive from Phippsburg, ME online.
Upgrades: The new strong tether worked really well. We also upgraded our tether management system with the introduction of threaded disconnects and an extension cord reel.
I need to improve the tether strain relief system since it has a tendency to slip and put tension on the communication wires.
Vacuums, bathtubs and missile silos...
That was our sequence of testing.
Using an Automotive vacuum test pump we connected to the main electronic cylinder and pulled as much of a vacuum as we could-- roughly 80kpa-- not sure what that translates to in terms of depth. But, importantly it held that measure for 30 minutes without lessening. (I read that stability is more important that vacuum pressure in this kind of test.)
Next, we submerged the rov in the bathtub and learned about the keyboard and gamepad controls. Wow is the video nice. The clarity of our and a razor we more than we could have hoped for! More importantly, after an hour of soaking we found no evidence of leaks or other issues. (In retrospect...)
Finally, this morning at 8:30, joined by good friends, we trekked off to what is purported to be an unfinished and flooded missile silo, essentially a small quarry, for our first dive.
The water was crystal clear, and the weather was beautiful. My expectation was that it would be a conservative first dive, but all of our secret hopes were to find wrecked cars or castoff bicycles and such, given that this place is a favorite hangout of the local teens in summer.
Admittedly though, I had my doubts about the selection of our first location when I first surveyed the area and saw the gentle slope of shore turn into a stark horizon line not 15 feet away and I assumed that like any good missile silo the walls were vertical and that horizon line was a sheer drop. On the other-hand, we were in a pretty good position to find out. Not to mention-- what would we see?
Like any first-run, we had our issues.
Sequentially we were challenged by boot up issues, tether management and buoyancy problems capped off by the somewhat "spirit crushing" loss of our vertical thruster prop discovered as we were heading over the precipice fighting a descent I felt was too rapid for a first dive. (Clearly the blade was not properly counter-tightened during the build).
But, not to be deterred we pulled off extra ballast, enough to make the ROV fully buoyant and practiced our navigation and camera work. We even managed to drive the ROV under a sheet of ice and capture some interesting footage (relatively speaking) of bubbles trapped under the ice sheet.
In all we logged 45 minutes on our first dive and despite the setback of losing the prop I must admit, I am quite pleased. We are steep on the learning curve and loving every minute of it.
Next steps: New prop, fine tune ballast, video footage management (extraction for playback and sharing) and set a date to head back to the silo.
We are getting very close to splash testing the ROV (in the bathtub).
The build has gone incredibly well but not without its setbacks of course. But far fewer than I had planned for and none of them catastrophic.
The most frustrating issue happened this past Monday and was solely the result of my own haste in wanting to power up the BeagleBoard. After assembling the port tube without a hitch I clearly wasn't paying enough attention and assembled starboard battery tube with the negative terminal cemented to the same end as removable end-cap catch.
Solution: Order Battery tube replacement kit. Of course Nima handled my request in short order. Thanks Nima! The parts should be here today in fact. (I just looked at the tracking info on USPS... maybe tomorrow).
In the meantime in hopes of continuing to be productive I put a note out to the ROV Community wondering if I could power the systems with only one tube of batteries. Answer, YES and with that, we were back to the build table! Thanks Brian G!
Here's a video that sums it up pretty well-- https://www.facebook.com/MaineIslandPerspectives/videos/1788141264845433/
Next steps: Software Upgrades (thanks again Brian G & Nima) and functional testing-- We've got a lot to learn about all the amazing features built into the new cockpit.
Also on the list: External Light Cubes & Laser adjustments.
Not too surprising, but the minutia of the build is proving less interesting to the kids. However, to their credit, they remain at the table and find something interesting in each step.
This video shows an example-- there is subtly so I recommend full screen and sound.
We are moving ahead!
While acrylic cement is not readily available at hardware stores, it is something professional acrylic fabricators carry and some are willing to sell the cement retail.
I found 2 custom acrylic shops within 30 minutes of the house (in Cambridge that is a mere 6 miles BTW). Unfortunately, none of the shops have weekend hours so I had to wait for Monday-- Not at all how I thought the project would go.
I'm sure we won't encounter anything else unexpected during the build, right?
On Tuesday night the girls and I began assembly in the short window between dinner and bedtime.. We had great fun and everyone is eager to get back to working on it again!
Admittedly our schedules are so full during the week that finding a meaningful block of time during the workweek for building is hard and we certainly don't want to rush the build process; the cement is unforgiving once it gets going!
I want to report that we are pleased with the build process so far. The instructions are clear and the parts are beautifully crafted so they fit together without force or modifications. I'm really impressed. Nice work OpenROV team!
My build team and I are very excited to report that our OpenRov 2.8 kit arrived last evening. I am particularly fond of the hat.
Admittedly, this morning as I write this I'm somewhat despondent now knowing just how hard it is to source acrylic cement locally. I had done some limited searching online during the week and felt confident that one of myriad local hardware/hobby/DIY stores carry it. But when I called ahead this morning I found that no stores carry it.
So, now I'm awaiting activation of an Amazon Business account and will have to wait for another delivery... And I've waited so long already...
But, I have the hat and the hat makes me happy!
Lastly, I'd like to announce that my naming committee has come up with some good options, BOB, Guppy, MonkFish to name a few-- but I've decided (unilaterally) to call it "The Kraken'
Here is the Wikipedia definition:
"The Kraken (/ˈkrɑːkən/) is a scary, giant and legendary sea monster of giant size that is said to dwell off the coasts of Norway and Greenland. "
Admittedly, I like the irony of scary giant sea monster, but really my number one motivator was so that each time we launched I could say "Release The Kraken" (reference "Clash of The Titans")...
My parents report that when I was about 6 years old I asked "how many anchors does it take to hold an island?” I don’t recall asking that, but I do love the question because I still find the waters of New England mysterious -- even when you stare straight into them they reveal little information about the world beneath. So it stands to reason why a six year old would presume that, like a boat, islands could drift away unless properly “anchored." In keeping with that I like to think my young self would be pretty excited to build an OpenROV kit with the express purpose of answering that anchor question once and for all.
My two kids (Hazel (9) and Camille (7)) and I are forming an Open Explorer group called Maine Island Perspectives. Our current plan is to use the ROV we assemble to explore the structures and life contained in the Maine ocean waters around Casco Bay. Right now I think we will tend to focus on islands and perhaps more specifically the transition points where they rise up from the ocean floor. It seems there would be ample discoveries to make there alone.
But, I admit, the focus is more my idea whereas the girls are more inclined to look for shipwrecks and treasure, and are eager to see how lobster traps and fish nets work. Truthfully, I am pretty excited by those ideas myself and suspect we'll be open to embracing unplanned adventures when they arise since we really don’t know what we will find.
That being said, the early project plan is to build out the ROV kit during these darker winter months. Then, come early spring we can take the ROV to local (Boston area) lakes and ponds and learn how to operate our new rig. Hopefully, by late spring/early summer, we can begin venturing up to Maine and begin our underwater exploration in earnest.
By the end of the summer I hope that we have shared wonderful experiences, full of surprises and discoveries that spawn myriad new questions and rev up our senses of awe and wonder. I also hope by then everyone feels competent acting as an expedition planner, ROV pilot, video editor and citizen scientist. Sound like fun, right?