The Post-Everything Update, Part II: Maker Faire(s)

I’m back in the zone.

After back-hauling 1185 miles over 2 days from Atlanta to Cambridge, Assachusetts (and discovering in the process that Budget Rent-a-Car’s computer system cannot comprehend a mileage with 4 figures, to my delight), I’m about to go back down about 20% of the way…to the NY World Maker Faire as part of the MITERS booth/table display.

Great… maybe I should have just stayed a few extra days and just went 80% of that distance instead.

The reason why I ended up bringing most of everything ever (i.e. more than just the robots for Dragon*Con)  down to Atlanta in the first place was because of Maker Faire practice.

The Atlanta Mini Maker Faire, hosted by Georgia Tech, was a week after the D*C robot event, so I elected to knock a week off the semester and show up after being invited by some of the GT Invention Studio folks.

The event was held in a not-too-large parking lot, and about 60 individual exhibitors were there. The above picture is of the crowd and a pretty nice electric Chevy S-10 pickup truck conversion.

With rideable objects now making up a majority of my project fleet, the event was a great chance to make sure all of them had some testing time without me in the loop. You are generally always careful and mindful of a vehicle’s limitations if you’re the builder, but no such luxuries are afforded when your vehicle is being tested by strangers who had about 30 seconds of instruction beforehand. I suppose a hallmark of a well-engineered vehicle is if anyone can operate it with 30 seconds of instruction and not have it explode.

Sadly, only about half of my “travel fleet” made it through the day.

Straight RazEr

As the previous test video showed, Straight RazEr did fairly well confusing GT students on campus. After raising the front ground clearance another inch, it could finally turn and go over the average sidewalk crack and things like that. I brought it to the MMF, and it performed admirably well throwing off several random people.

The trick with sensorless brushless scooters is that you cannot just stand on it and hit the throttle. At least, don’t do it multiple times, since the motor pulling stall current across the controller will heat it up quickly. While most everyone understood the lecture and handled this part fine, I’m fairly certain the one person who didn’t caused the demise of Straight RazEr. A few seconds after I handed it off, I heard cries of “smoke!” and “fire!!” from the crowd behind me. I turned around and without much reaction, watched the massive plume of Turnigy smoke billowing out of Straight RazEr’s upper rear deck.

The short-circuit current desoldered my Deans main power connector. Some of the smoke and “Turnigy splatter” looks like it also made it out of the power access holes.

That SR ended up exploding wasn’t really surprising – the fact that sensorless vehicles need to be “push started” is really an alien concept to most people unfamiliar with them, and the majority push off too slowly or weakly anyway. The same reason is why very few people can actually ride melon-scooter, which also has a much slower “pickup speed” than Straight RazEr due to the latter’s much wider gearing.

Oh well.

Because Straight Razer was built mostly as a troll and the controller can be replaced later, I’m not going to try to bring it to NY Maker Faire. It’s considered out of commission until further notice. I might try throwing a melontroller on it some time later, but that involves adding sensors to the motor.

Speaking of melontroller…

RazEr rEVolution

I don’t have pictures of RazEr at the event (it looks the same, trust me), but I’m definitely amazed at how well it has stood up. Not only was it extensively used to the point of battery depletion at the end, but both the motor and Melontroller 2.0 have survived what amounts to a continuous +/- 50g minimum shock test. Because of the very hard wheels I chose by mistake and ended up designing around (90D and 90A hardness for the rear and front!), every little sidewalk or road feature was transmitted without damping into the drivetrain. After the day of demos, I rode it twice around GT’s Yellow Jacket Park square essentially full throttle the whole time. Overall, RazEr’s design has proven itself to be very robust. I’m particularly relieved that Melontroller 2.0 is a stable version from which I can improve (you know, adding things like a real logic power regulator), so this is one goal for this fall and winter.

With Jamison’s new hub motor scooter sporting 60A Colson wheels, I’m also going to remake the front and rear wheels to use them. Maybe RazEr can actually be a useful vehicle after that.

However, for the time being, RazEr will be at NY Maker Faire, completely unchanged except for a full charge.

Segfault

The biggest and most awkwardly shaped member of the travel fleet, Segfault was already flaky before I left, and it only got worse at the event. Not only is the controller, originally designed to last maybe a week, now entering its 10th month of use, but the drive motors are slowly giving out too. The left Banebots P80 gearmox lost an internal shaft retaining ring some time ago, which means occasionally the left wheel just completely disengages and spins freely. I’d keep the thing running by literally just kicking or hammering the wheel back in. But finally, at the MMF, this happened.

Alright, I’m finished. Before this, the controller had pretty much been totally reduced to a ball of twitching and noise. The breadboards are slowly falling apart (their contacts falling out the bottom side after the glued-on paper backing expired) and most likely the contacts are also oxidizing and being sporadic. With all of this, Segfault is officially decommissioned and the current version will not be repaired or upgraded. I will probably part it back out and repair the left P80 motor for future projects. The vehicle is too big and unwieldy, and has more than served its purpose of control theory demos, so if I end up building another Segway-vehicle (ahem) it will be much smaller and lighter.

In the mean time, anyone want a full aluminum Segway-like vehicle frame? Just add your own P80 motors and Arduinos.

Because of the state of utter wreckage it’s in, Segfault is of course not coming to NYMF.

Land-bear-shark

This thing was a huge hit, and I’m proud to say that it also survived the day unscathed (though with quite a few more stickers). It looks very squat and unimposing, but few people could actually stay on and ride it because of how high off the ground the rider stands and the short “wheelbase”. The Beast-it-trollers handled the whole day’s operation in 90-95 degree weather with no problems after I upgraded the drive FETs to IRFB3207 4 milliohm parts, instead of the old IRF1407s which flamed out two Swapfests ago.

While the Advanced Beast-it-Troller has been assembled and bench-tested, I have not installed them or written the software for them… nor do I intend to for this weekend. LBS will be traveling to NYMF too, and I’ll probably be tooling around on it all day since it has about 25 amp-hours of battery onboard, and NYMF is half parking lot and half rolling grassy fields and gravel lots. Hell yes.

Other things that are also coming

I’m going to bring Überclocker and Cold Arbor along as display sculptures. Clocker is functional (not very battleworthy, but things do move) so it may participate in some demos.

The Kitmotor Demo Stand will probably be spinning on the table all day so more of you people will go and build scooters.

Finally, I’ll also truck along the erstwhile Make-a-Bot, which has been making parts for all the other projects almost trouble-free since last December. It’s now a generation and some behind the kit 3d printer features curve, and I intend to rebuild it in the near future. Maybe I’ll park it in the 3d printer nest, next to all the Makerbots to troll Bre Pettis. After all, it’s about 75% faster than a stock Thing-o-matic and 1000% more \m/etal.

 

What is a Singapore?

It’s the slightly confused illegitimate offspring of a British noble with a Malaysian mistress, who grew up in the care of a Chinese nanny. That’s just about the quickest way to describe it. It’s an interesting mashup album of Southeast Asian culture with British heritage. The official language is English, but on the streets people usually speak either Mandarin Chinese or a hybrid of English with Malay and Chinese (which sounds weird, but I can parse it when I can phonetically understand it due to the grammatical structure being not unlike Chinese…) You also drive on the left side of the road and walk on the left side of the sidewalk, which, needless to say, caused me to almost run into people several times and the aftereffects of which are still being felt since I now have to switch back to instinctively dodging oncoming pedestrian traffic on the left hand side once more.

So what’s the actual reason I ended up halfway around the world for a week? Some time last month I was invited by the Singapore University of Technology and Design, under the auspices of the Department of Mechanical Engineering at MIT, to attend a January information & future student recruitment session promoting the new university. SUTD is partially a MIT collaboration, the goal of which is to export key features of the various design schools and courses here and create an institute centered on the “hands-on” style of teaching design – whether it be product development, engineering, architecture, or whatever else requires design, which really is everything. Several of my peers in MechE have already been working closely with the SUTD nucleus to pilot and explore potential directions for the engineering side of things.

Now, how better to promote “hands-on” than entertaining the audience with a bunch of rideables and demoables? That’s what I ended up doing, at least to the limit of what international baggage allowances deemed acceptable. I ended up physically bringing RazEr rEVolution, the “homicide-skates“, Nuclear Kitten, and a pile of 3d-printables. Everything else, I just made some informative posters for, which will be shown later.

On Saturday morning, immediately after punching out my sleep schedule and tying it to a fire hydrant, I struck out retracing the steps of the great explorers before me.

Specifically, I started scouting out places to get parts. Something you don’t see (often) in Western nations and which I’m glad has stuck around as a behavioral tic of Singapore (if we want to talk about confused offspring) is the abundance of places to get non-consumer-grade parts and components. Such a “fix-it” and “build-it” culture has, sadly, all but died out in most Western nations. During my last trip to China, unfortunately before this current iteration of the site dating back to July 2007, essentially all I did was run around Beijing checking out the hardware. And I’m content to say that my decidedly non-tourist behavior here has been just as productive.

In Sim Lim Tower (NOT SIM-LIM SQUARE ACROSS THE STREET) there are three floors worth of small shops and stalls which sell everything ranging from the very commercial, such as these prepackaged electronics kits:

… to the slightly out of the ordinary but still organized bulk parts and discrete components, such as these LEDs (and up to and including SRAM chips and entire microcontrollers). See, I almost feel like I should get a little cute baggie and a mini-shovel and just start mining in the bins.

And then you have things like this physical embodiment of what my basement will probably look like in 30 20 10 years time.

Now, since the Singapore Dollar is roughly on par with the US Dollar (exchanging at about S$1.25 to US$1 as of the now), I wasn’t able to clean this guy out. British Airways would have flipped a shit at me anyway, and I probably would have shut down all of Boston upon arrival.

It also meant that all I could do was press my nose against this guy’s display case:

If you know me, you know that as a Mechanical Engineer I have a penchant for enormous semiconductors. Sadly enough, they weren’t that much less expensive than if I bought them new and commercially. These guys fix industrial motor inverters and deal in  electric motor drives, so it’s unsurprising these modules are just chilling in a store window.

The vast majority of these small shops are a small storefront crammed with wares and having a single internal aisle about 0.8 persons wide, also stuffed to the brim with product. You generally don’t go and pick something off the shelf; rather, you ask the guy about what you want and he (somehow) finds one. It’s the same process that governs how to find parts at MITERS, except the shopmaster isn’t me. This place had a great selection of random small hand tools and some fasteners and other implements. It’s like if I distilled an American hardware store down to a fuming concentration.

The collision of Southeast and West (because let’s face it – Singapore is not really “East Asia” geographically) results in amusing regions of stability like this:

It’s some hybrid burger place that serves both conventional, American-style hamburgers to Japanese and Malaysian/Indonesian inspired burgers of various flavors and architectures. I approve wholeheartedly.

Another day, another random small business park: an electric bike dealership.

This place actually has a website, and they sell both bikes and replacement parts therefor. Those shady-looking brushess controllers you see on Ebay all the time?

Yeah, I got one. Hey, yet another reason for me to avoid building a motor controller.

okay, what did i actually come here for again?

Oh, right.

The event itself was held at a youth center closer to town. From the outside, it looks like a hybrid of the Media Lab with a YMCA, built around an enormous Luxeon Star LED.

Oh, did I mention the event was geared towards women and girls? I didn’t know that until a few days beforehand either.

Delight turned quickly into disappointment as I discovered they actually meant geared towards junior high and high school students, in an attempt to entice them towards a career in design and technology. At a university which, conveniently, is opening to students about when they graduate. Hey, I’m about to graduate too (I think), just from the next level up.

Much of the event was a presentation and talk by the SUTD nucleus. Essentially all the top-level admins were in attendance, including the SUTD President, Tom Magnanti, a former MIT Dean of Engineering.

Along the perimeter of the conference room was the poster and demo session featuring works by SUTD and MIT students and interns. The students wandered around the displays before and after the main talks.

Guess who spammed about 40% of the posters by area?

You can clearly see the goodies on display, and the Segfault video playing on both my computer and a supplied spare screen. The posters, from left to right, are about hub motors, combat robots, 3d printing, and LOLrioKart. Okay, and Segfault too – I wasn’t sure what the unifying theme of those two were besides “EXPERIMENTAL VEHICLES”. For reference, the actual full size PDFs  are linked.

Don’t nipick the details – I had to do alot of condensing and de-technification (is that even a word?) since I wasn’t sure what the audience was going to be even as I made them. Also, spot Make-A-Bot‘s new project name.

The event itself was about 3 hours in duration, but with a long taper-off at the end when students were checking out the posters. So yeah – essentially, I got flown to Singapore for a week (airport-to-airport) to attend a 3 hour event. But it was awesome. And warm – the weather hovered around 85 to 90 degrees (F) the entire time. Upon arrival in Boston, I was greeted by 34 degrees, piles of dirty and melting snow, and of course rain. Then it proceeded to all freeze solid.

Sigh.

I hate to knock pictures from Facebook, but I absolutely must share these two from the SUTD album of the event. Here’s the Provost of SUTD taking a spin on RazEr rEVolution after the event concluded:

And finally, Big Man himself, Tom Magnanti:

So my new goal is to get L. Rafael Reif and Susan Hockfield to take a ride on RazEr.

Also, flower bunny.