As was previously reported here on MAKE, recently, a group of us OpenROVers journeyed to Hall City Cave just outside of Wildwood, CA. The goal of the trip was to do a shakedown of ourselves and the ROV in the field, and as a mission, determine if (inside the underwater cave) the vertical cave shaft connects with the 45 degree sloped shaft. The cave was the original inspiration for Eric to begin creating an ROV, and has since evolved into the open source project that it is today.

Needless to say, we had quite an adventure – driving through heavy snow, trekking along mountain paths with robots and tool boxes, landing single engine planes on snow covered runways. We’re still digesting much of what happened and we’ll be writing up a longer report of the adventure soon, but we wanted to give a quick update on how the robot worked!

When it comes to small ROV design, there are three general fields that always seem to require the most development:

• Onboard electronics/embedded system design
• Communication and power through a tether
• Water and Pressure proofing

Embedded Systems
Background (and what we’ve been doing so far):
OpenROV is being developed as a platform that can support scientific research and tech development. In order to be as effective as possible at this, we’ve been doing lots of research on how to get a small computer, such as an Android phone, BeagleBone, or the upcoming Raspberry Pi to host video, monitor sensors, and control thrusters while communicating to the surface. Bran Sorem has been developing some code for embedded Linux which could be run on these devises and has also been working on a GUI interface that will make OpenROV intuitive and satisfying to operate.

Enter Bran…

I’ve been working on the software for OpenROV and believe we have mostly established a good base for future development. We are currently using a BeagleBone as the primary onboard computer (though we plan to move to the Raspberry Pi once that’s feasible) with an off-the-shelf webcam attached. The goal of the software is to provide an easy-to-use and simple-to-extend, yet powerful, framework for operating the vehicle. For that, we are using Ubuntu Linux as the operating system with NodeJS on top to serve a webpage that allows the ROV to be controlled from any modern web browser.

Video is handled by a simple OpenCV program that captures frames and saves them as JPG’s, which Socket.IO then sends to the controlling browser. Having support for OpenCV greatly opens the opportunity for development of more advanced applications (such as tracking fish). Socket.IO allows for full-duplex communication – which will handle the video updates as well as directional control of the ROV.

So far, I’ve been working to get a live video feed working but have run into a stumbling block (mostly the fact that I’m learning NodeJS and OpenCV as I go). The OpenCV program accepts a folder (the current date) as an argument then waits for stdin: each line of input is a file name (current time) to save the image as, which the program then uses to grab a frame from the webcam and save. This will occur continuously until the connection is broken. The problem right now is in the NodeJS application – it seems to be spitting out the correct filenames, but I’m trying to pipe the process.stdout to the child.stdin and having trouble. Any help or advice would be GREATLY appreciated.

There is a lot more to come in the future, but first we want to get the video working. The code will be hosted on Github.

For our resent trip, development had not gotten us to the point where we could control the ROV with an onboard computer, so instead we just used an RC controller which talked to the receiver on the ROV through a long wire which effectively ducted the RF through the water.

How you can help:
What do you think? Have you done any embedded systems work with a BeagleBone? Any ideas for transferring live video over an Ethernet connection (that can also fit in our water-tight cylinder?

Tethers
Background (What we’ve been doing so far):
Tethers are often the most challenging part of an ROV to develop because they must be able to communicate large amounts of data and power while still remaining agile enough to allow the ROV to move easily through the water, and they must be either neutrally buoyant or light enough to not drag the ROV down as more and more of it is payed out into the water. Especially for small ROVs like OpenROV 2.2, the best solution is to make the tether thin and light weight enough that buoyancy compensation is not needed.

For the Hall City Cave trip, we used a twisted pair of 28AWG stranded wire, and it seemed to work very well- if we had been using thicker tether such as Ethernet, the ROV would have had a much harder time moving around, and the weight of the tether would have made it hard for the ROV to maintain a given depth. We’d like to continue using very thin tethers such as this one (or perhaps extremely thin coax such as RG-178), but the challenge we’re facing is how to send high bandwidth data through it.

There are several approaches to this. For starters, you could go analog and use a video balun to send images from an RCA-output camera up from the ROV while allowing RF signals from an RC transmitter to pass down the tether. Or, you might be able to use one of these fancy devises to convert double twisted pair Ethernet to single twisted pair.
Finally, you could just use a data over powerline system (as discussed here).

How you can help:
These are some of the ideas we’ve thought of, but we’d love to see some other thoughts on how do do this. (Remember once again, all the ROV-side equpment for this has to fit in a 90mm ID by 150mm long tube!)

Waterproofing
Background (What we’ve been doing so far):
For waterproofing the electronics, we’ve had great success with our cylindrical housing and laser-cut acrylic endcaps. We’ve been potting the pass-throughs with epoxy. The brushless motors have received a coating of marine-grade resin to prevent oxidizing.

How you can help:
The method has worked so far, but it’s ripe for an easier and less time-intensive process. Let us know if you have any ideas for potting or motor waterproofing.

BONUS: Add-ons!
Background (What we’ve been doing so far):
One of OpenROV 2.2′s greatest features is it’s payload module bay. We’ve put mounting holes in the bottom of the shell of the ROV for up to four M5 threaded rods, each spaced 50mm apart. The purpose of this is so you can make your own payloads (such as robot arms, metal detectors, chemical sensors, etc) which can mount easily to the bottom of the ROV. The width of these payloads can be up to 135mm or 200mm if the on board battery packs are removed.

How you can help:
We’re always looking for ways to improve OpenROV, and having a community of people thinking about it is the best way to get new innovation and different perspectives. After all, that’s what Open Hardware is all about!

Feel free to check out the OpenROV forums for some of the other strategies we’ve checked out. Also, let us know if you’ve got any other adventure ideas!

More:
Read David Lang’s Zero to Maker column here on MAKE

Here’s the fourth episode of MAKE‘s podcast, Make: Talk! In each episode, I’ll interview one of the makers featured in the magazine.

Our maker this week is Steve Lodefink. An inveterate tinkerer and “broad-spectrum hobbyist,” Steve just can’t say no to a cool project. At three, he was already reverse-engineering the peanut butter and jelly sandwich: “I figured out where all of the parts were, found a good tool, and built one. I’ve been doing it ever since.” He lives in Seattle with his wife and two sons, two cats, five tarantulas, and 24 African cichlids, and thinks that one of life’s great pleasures is a really sharp aged cheddar cheese. “I’m a simple man,” he says. He looks at life’s debris at finkbuilt.com.

I talked to Steve about his Easy Sunburst Guitar, Atomic Ball Clock, Soda Bottle Rocket, and more.

And, at the beginning of the episode, Maker Shed Marc de Vinck describes our new Tiny Wanderer Robot Kit, an autonomous robot with a $2 microcontroller brain.

Related articles

• Steve Lodefink’s Pinewood Racer Bodies (boingboing.net)
• Steve Lodefink’s Pinewood Derby Racer (makezine.com)
• Steve Lodefink’s Finished Pinewood Derby Racer (boingboing.net)

Anyone who’s ever tried woodcarving using a chisel or gouge knows how difficult it can be. It is not trivial to translate an idea — a concept of a shape — from one’s imagination into a physical form. Whether using your hands or a manual tool, manipulating a raw material at will is a demanding task.

FreeD (by Amit Zoran & Joe Paradiso from the Responsive Environments Group at the MIT Media Lab) is a handheld, digitally-controlled milling device. It is guided and monitored by a computer while still preserving the craftsperson’s freedom to sculpt and carve by hand. The computer intervenes only when the milling bit approaches the 3D model, which is planned beforehand. It does so either by slowing down the spindle speed or by drawing back the shaft; the rest of the time FreeD allows the user complete freedom to manipulate and shape the work in any creative way.

With advanced CAD software, free access to tutorials and 3D models, and a vast online community of makers, today we can make, download, or modify a CAD model of almost any desired object. We can then fabricate it directly through a digital process. The idea behind the FreeD is to allow us to engage with the physical material, not just with the CAD environment, freeing us to create our own interpretation of the virtual model. Thus, even though we are working based on a generic design, we can create something that is one of a kind.

In traditional crafts, the craftsperson’s tool techniques and creative decisions immediately influence the final artifact, making the output a reflection of the fabrication process. The same applies to digital fabrication through use of the FreeD. Several users may use the same CAD model, but end up with a different result, reflecting each person’s unique process.

In today’s project on diyphysics.com, David Prutchi shows how to build a Cockcroft–Walton multiplier using a “ladder” of capacitors and diodes on perfboard, submerged in mineral oil, inside a sealed plastic container. The multiplier takes high voltage AC, e.g. from a TV flyback transformer, and both rectifies it to DC and steps it up considerably. David reports outputs of 250kV given 12V input at the flyback driver. A handy feature of his design is that it can provide high-voltage DC of either polarity with respect to ground.

And yes, to be clear about it: Making a mistake here could be very dangerous. You should understand and be comfortable with the proper safety procedures for handling high voltage electricity and charged capacitors before seriously considering a project like this. [Thanks, David!]

Jigsaw Renaissance Housewarming Party

Seattle hackerspace Jigsaw Renaissance has moved into its new space, and is throwing a party to celebrate!

Jigsaw has moved around a bit in its life. We started off in a tiny Quonset hut beneath a construction-riddled bridge. Then we were in the Madison space, and then in our temporary Inscape home. But now, gentle readers, the time has finally come! We’re in a space that was specifically built out for us, all organized (or at least it will be by this event) and made up just the way we want. There will always be room for improvement, but we’re pretty happy with the current state of things. Please come help us rejoice in this newness, this stability, and this accomplishment.

On Saturday, February 11th, from 15:00 to 19:00 (or 3p-7p if you prefer) we will open up our doors and welcome in the public to celebrate our new home. Please join us. Invite your friends. Bring your projects to show. Children absolutely welcome.

3D Printing Workshop at Ann Arbor’s All Hands Active

Pocket Factory is offering a 3D printing workshop tonight, 2/9, at All Hands Active.

(PF looks cool, they’re traveling across the U.S. spreading the good word about 3D printing!)

Louisville’s LVL1 Announces 3 Makership Recipients

LVL1 is proud to announce the recipients of our groundbreaking Makership program!

We had initially raised enough funds within our community for 2 Makerships. In a surprise twist, LVL1 Google Group subscriber Dmitry S. graciously donated $250 to fund a 3rd! Thank you Dmitry!

See their blog post for more information on the winning makers.

New Jacksonville Hackerspace JaxHax Opens its Doors

Catch up with the guys at JaxHax Makerspace and take a look at some of the improvements we’ve been making around the space. We have a short interview with Ronnie Hinton and Dan Bidleman, co-founders of JaxHax, as well as clips of built-out spaces and projects in progress!

Ham Radio License Class at Davenport, IA’s Quad Cities Co-Lab

The QC Co-Lab will be hosting an Amateur Radio Technician’s License training course. This class is being taught by Bob Cannon (N9TPQ) and Doug Dechard (KC9HGP) and will cover the fundamentals of Amateur Radio (HAM) including the test prep material in addition to common practices, radio etiquette, and radio operation. The cost will be $40, which will include books, class materials, and admission to the test.

Looks like the sessions will take place Saturdays, 2/25, 3/3 and 3/10 from 9am-Noon.

Blue Hackers Meetup at Jigsaw Renaissance

Hackers, makers, and geeks are not immune from mental health challenges. In fact, our subculture brings with it specific challenges related to breaking down barriers to accessing support for mental health issues.
Join us for a guided discussion on:
-risks and benefits of seeking support
-how to survive when your brain wants you to die
-how to manage someone else’s crisis without creating one of your own
-when to hire a professional brain hacker (psychiatrist/therapist)
-next steps to increase support in our community for mental health concerns.

The meetup will take place this Sunday, 2/12, from 4-6:30pm. See the event page for more information.

Orlando’s FamiLAB and the Orlando Mini Maker Faire Announce Makerships

Orlando Mini Maker Faire and FamiLAB, Orlando’s Hackerspace (Community Lab) have partnered to create “Makerships” to help 3 deserving recipients create (or finish) amazing projects to be displayed & demonstrated at Orlando Mini Maker Faire 2012, held on May 26th at FamiLAB in Longwood, FL.

Makership Award Recipients will receive $CASH$ and three months of FamiLAB “Maker” level membership in order to make their project idea a reality.

Two Recipients will receive a $100 Project Stipend and 3 Months of FamiLAB Membership at the “Maker” Level ($150 value!), while one recipient will receive a $300 Project Stipend and 3 Months of FamiLAB Membership at the “Maker” Level ($150 value!)

For more information, or to apply for a Makership, please visit the Makership page of the Orlando Mini Maker Faire website.

If you can endure the relentless puns, the tag aggregator page for MakerBot’s Project Shellter is a fun read. There are cool pics of the denizens of MakerBot’s official “crabitat” sporting their fused-filament homes (such as “Paris Shelton,” above, in a lovely little daffodil yellow number) as well as oddly touching night-time videos of each crab adopting its new home for the first time. [via nerdstink]

More:
Hermit crabs in glass

HaD writer Caleb Kraft of Springfield, MO, sexed up his VW bus with a lovely (and Cthulhu-esque!) elephant mural as well as stained glass sun visors that complement the painting. Caleb says he “never really painted before” — ORLY!? Looks pretty amazing to me.

If you’re celebrating Love Day this year, and could’t make it to the Kwik-E-Mart before they sold out of Lord Huggington, you might consider going the handmade route, in which case you could probably do a lot worse than a dozen of these realistic duct tape roses from Instructables user DIYHacksAndHowTos.

Now, if you’ll excuse me, I have to go outside and assemble Love Land. [via CRAFT]

More:
Heart-Shaped Hack Box from Evil Mad Science Labs

Columbus, OH makers Kevin Holland and John Staskevich have built a seemingly fun to play hackable synth using a PIC microcontroller, 8-bit DAC, and analog low-pass filter. It includes an integrated step sequencer and simple, intuitive controls. The device was built with hacking in mind, so you’ll also get a spare hardware DAC channel, on-board prototyping area, and ICSP port to modify, update, or completely rewrite the firmware. It’s all housed in a clear laser-cut acrylic housing so everything’s easy to see. [Thanks, John!]

It’s been over a decade since I’ve thrown clay on a wheel, but watching this video, by David Hobson, of Dorset-based potter Jonathan Garratt, makes me want to return to the art. Garratt is a true maker from beginning to end, including farming his own clay, mixing it in a blunger, drying it over a month, then processing it through a pug mill. He chops his own wood and claims to have nearly 100 tonnes of wood stacked in sheds and under tin tarps outside, which he rotates out on a two-year cycle!

The combination of using local clay and firing with wood gives his work a “flavor” and “character in the finished thing” that you can’t get from packets of clay powder and other firing techniques. Packing his kiln with about 1.5 tonnes of thrown pottery, he says it’s “a bit like a 3D jigsaw.” He fires the clay for 18 hours and 4 days later opens up the kiln to reveal locally sourced and made earthen masterworks. I am, to say the least, impressed!