Category: mikuvan

Some Random Little Things Updates! Caddiebike, RUSTY MEMORY Part III, and Inexpensive Chinese LED Lighting

chorl3 Comments

Here at Big Chuck’s Robot Warehouse & Auto Body Center, the fall semester is generally the quiet one where I actually, you know, get things done. I’m not herding go-karts during this time, unlike the spring and summer, so it’s shop facility upgrades and working on stuff at a less frantic pre-competition pace. Like last year, there’s also a section of the popular “How to Make [A Mess Out Of] (Almost) Anything” class running in the IDC fab shops, and I run orientations and trainings on our equipment for those students and more. In fact, life is so chill right now that I haven’t even touched Chibi-Mikuvan since Miku Expo. That’s how bad it is.

Of course, this just means “big van work”, among other things. Here’s a general recap of the past month, or thereabouts.

Caddie-bike

Also known as “that huge e-bike thing”… or “the battleship”, this thing was part of the inaugural cruft run, the first of many, that a running big-Mikuvan has enabled. It’s a Wavecrest Tidalforce iO cruiser bike, with a step-through frame. This thing is massive – it weighs something like 65 pounds in stock configuration, and its soft and boat-like handling earned it the nicknames shown. It’s been hanging out in the shop for nearly the past year in a quasi-operational state.

With the advent of another promising winter, I’ve decided to ‘resto-mod’ it into something usable. Melonscooter, in all its incarnations, just does not do snow at all. The fat scooter tires means you float above the snow and can’t get either traction or stability, and both wheels gradually turn into solid balls of snow. On the other hand, bikes do somewhat better, especially road bikes with thin profile tires, since they ‘cut through’ the snow – the phenomenon is something I observed very clearly watching people try to commute during winter, and borrowing a bike or two. You’re also higher off the ground in a bike, so the black slush that the snow inevitably becomes after 24 hours stays a little farther away.

To get the bike to a functional state, I decided to ditch the front hub battery like many who inherit them. There’s a small community of Wavecrest enthusiasts who have documented mods and changes to make. In particular, I’ve been in contact with Ambrose of ebikerider about the nuances of using the bike with an aftermarket battery.

First mission was to get a new front rim, since the battery-laden front rim was being removed. I rolled it over to the bike shop for a quick appraisal and parts recommendation. Cambridge Bicycle and MITERS go way back, so I usually patronize them when I can.

They also get to put up with a slew of student questions along the theme of “How can I use this on a go-kart?” at the end of each semester from me, so I also feel bad if I don’t use their business for a legitimate purpose.

Notice the the added cargo box and bag on the back. This was where I was going to put the new battery pack; specifically, the battery will go into the center cavity, leaving the upper cavity above it and the side bags free for actually carrying stuff. All of these bags ‘telescope’ a little, so it’s a fair amount of enclosed space.

Observe, enough lithium to level a small city block.

I decided to dig through the lipo nuclear arsenal to assemble a pack. To my delight, these four 4.5Ah 10S lithium polymer packs fit perfectly, four across, in the center of the bike bag. So that was a quick decision.

These are actually the batteries from the very first generation of tinykart before Shane switched to A123 cells. They have been sitting in various rooms for a while, so the first order of business is to fully charge and balance them both. I borrowed a TP1430C charger from Peter while I purchased one and it was on the way.

Surprisingly, they were in good health and all reached 4.2 volts a cell without incident. LiPo batteries like this tend to be a little more fragile because of their soft shell.

To join the packs in parallel, I had to make another Adapter Which Should Not Be Made, a 5-to-1 Deans adapter using 8mm bullet connectors as the wire-joining socket. I used the Big Weller with the 1/2″ diameter tip for this join-five-12-gauge-wires-at-once job. To prevent errant shorting when plugging in more batteries, each of the male Deans connector ends is shrouded in loosely-shrunk heat shrink tubing.

The other end of the adapter goes to a 45A Anderson PowerPole connector which is used throughout the bike.

The final outfit, with a new wide 26″ front rim. I also replaced the back-curving ‘cruiser’ style handlebars with straight bars that I could stand using. I’m not sure why the cruiser style bars are popular, but my wrists clearly were installed in the wrong orientation for me to use them comfortably. The LED cluster a cheap “56 LED” (That’s the only model name I can find for it) bike light I bought long ago for Melonscooter 1 whose mount I lost, but that was resolved with a 3D printed part.

…and that’s it! It hasn’t been hotmodded to hit 65mph (yet), nor can it go from Boston to New York (yet). I’ve put about 30 to 35 miles on it, on purpose, to test out the speed and range. With the lithium pack, I empirically obtained a range of 25 miles before the motor controller’s own low voltage protection kicked in. This was without me helping it much – if I put some work into it, I’m sure the range will be much greater.

Caddiebike is named such in homage to the floaty ride characteristics of old American ‘land yacht’ luxury cars, since it (still) weighs over 50 pounds and has very soft shock absorbers.

Operation: RUSTY MEMORY Part III

Van bodywork begets more van bodywork. The skills I had to learn and practice on big van work contributed to my ability to tackle Chibi-Mikuvan’s body shell, and the improvement in those skills I got from Chibi-Mikuvan is applied back to big-Mikuvan. I’m trapped in an infinite van loop.

Once again, the onset of cold weather is the impetus for fall-season bodywork. There are still a few problem rust spots that I haven’t gotten to, such as what I consider to be the ‘end boss’ area, the boarding steps, which have holes on both sides. However, for now, I have the area shielded from most water intrusion, so it hasn’t gotten worse.

Last month, I wanted to repaint some more of the very problematic left side. For some reason, the left side of this thing is way more scratched and dented. In particular, the left rear corner had been deteriorating for some time:

I originally wanted to sand down this area a little and just perform a simple repaint, but of course, due to the effects of Famous Last Van Words, there is no such thing as “just [verb] a simple [noun]”. By the time you see the rust bubble, it means it’s too late. The lower corner of the wheelwell is pretty well disintegrated, but I declared it “out of scope” for the day and just proceeded with repainting the dent at the top, which seems like somebody sideswiped a solid object very slowly.

Here’s the area cleaned up a little. The bottom corner has now been “scab picked” so the extent of the hole is visible.

Early October is the last time it’s warm enough to paint outdoors. Even so, I made sure to bring a heat lamp out and point it at the job as I applied more coats.

An area at the front was also repaired during this same session, since just because they write “AUTOMOTIVE” on a can of paint, does not make it fuel-resistant. The occasional fuel pump spill in that area has eaten the clear and color coat a little.

I left the area around the hole unpainted and marinating in “rust converter” spray for the next week or so while I waited on a good opening to bust into the FSAE and Solar Car team shop, where the auto lift is. It is often joked that I will eventually turn the whole thing into a composite-bodied solar car.

Here’s the hole after some more ‘scab picking’. The idea is to trim the area clean with a Dremel, cutting wheel, and abrasive grinding bits, then add several layers of fiberglass cloth, then smooth to shape.

From the inside, here’s a view of where the metal has degraded into holes. This part will be cleaned and trimmed also. In fact, since this is not on a very highly visible part of the vehicle, I am actually just amputating the entirety of the lower inside corner there, where the “bite mark” is taken out, instead of trying to reshape it.

Everywhere there is rust, there is a small rust demon that must be exorcised.

In the middle of the hole-bridging process. My standard so far has been 3 layers of glass, which I surmise makes the region actually more rigid than the rest of the thing. I don’t like to half-ass repairs: if I do something, it’s full-ass, but still ass.

After the resin sets, it’s time to build up the corner with Bondo a bit. I still hate Bondo, but it’s so useful as a material for this kind of work. It’s almost like they designed it for this purpose or something.

There’s two stages of Bondo-work that I seem to do now; first, is “glob on with reckless abandon”, roughly sculpting said reckless abandon to shape, then finely sanding to a visual contour.

A 2nd round then goes on to fill hole and low spots, and that’s when I put away the power sander and resort to hand sandpaper-pushing, since the power sander would be too aggressive at that point.

Here’s the result of “pass 1, fine sculpt”. There’s still some uneven spots to be filled in.

After pass 2, it’s time for priming and painting. I’m not a classic car restoration neckbeard, so the details are not perfect – the oblique lighting in fact reveals the small errors in the contour I left.

I am a adherent of the 5-foot school of cosplay costume creation and automotive bodywork: If it looks fine from like 5 feet away under daylight, and functions fine, then I’m cool with it.

In fact, the only way someone would see this if they were running their hands along it. And if someone is feeling up the underside of my van, then I might need to have a few words with ’em.

The few little black spots are accidental spillovers of the thick black underbody coating paint that I thoroughly smothered the obverse of this area in. The little bit of “orange peel” effect reflected by the room lights was taken care of also.

Letting everything sit overnight under the influence of a large halogen work lamp, here’s the result the next day!

There’s only two major rust removal project left on this thing – the area just behind the front left wheel, which had the most extensive large-area damage, and of course the step holes.

Inexpensive Chinese LED Lighting

Ah, another Inexpensive Chinese name, unfortunately not nearly as cool as ICBM (Inexpensive Chinese Brushless Motor), which I’m glad has spread beyond my immediate influence.

Under the category of “I have nothing left to fix, so I have to start making problems” van work is replacing all the auxiliary lighting with LEDs. I originally conceived this as a step on the way to electrification in order to reduce the power consumption of lighting and other vehicle systems. So perhaps, it’s just keeping the dream alive. Based on the prevalence of 5W “T10” type bulbs, I calculated that I could reduce the power draw of the auxiliary lighting by 66%.

The plan is to replace all the dashboard warning and info icon lights, interior lights, and all the exterior market lights, reverse lights, brake lights, but not turn signals. Why? Because the flasher unit is an older mechanical type, so it counts on the high current draw of filament light bulbs to function. It’s also deep in the dashboard area. No, it’s not located on the fuse panel like a reasonable engineer would do so. This is a job for another day.

I gradually forgot about this as other van shenanigans took over, but DealExtreme made the critical mistake of showing me a promotion for automotive LED replacement bulbs a few weeks ago and made me remember again. The pain is real.

This is what happened. This isn’t the entire haul, either – I also haunted eBay and Amazon simultaneously like when hunting for any other Chinese-supplied resource, and got a few better deals and other form factors from there.

In the fashion I typically preach when it comes to procuring Chinese parts for peoples’ projects, I “shotgun selected” these bulbs. Meaning, I bought a whole bunch of variations and small specification differences to cross correlate which ones are clones and which actually perform up to their nameplate. The fact that you have to do this is a pretty important consequence of buying cheap Chinese parts that many engineers and makers fall victim to, which some of my students get a taste for in 2.00gokart.

I chose to go “middle of the road” sorted by price. One of my own rules of thumb when it comes to Chinese sourcing is to never buy the cheapest thing unless you’re out to use it for something other than its stated purpose; and the most expensive thing is basically like buying from a “real” name brand or established vendor, so you might as well just do that for customer support and service.

 

The dashboard job was actually quite quick, since I only had to remove the instrument panel and not the whole dashboard. The backlighting was made of three T10/W5W lamps, which I replaced with “1 watt” LED clusters, and the small icons were all T5 miniature bulbs with the exception of the fuel level indicator, which was weird (I later found out it was called a “T4.7”, but I am not going back in for just 1 light right now).

I chose these for all T10 size lamps, so I have a few different colors – white, warm white, red, and amber. I am not a fan of “warm white” in general, even in indoor lighting, and getting rid of the awkwardly yellow “white” lights was part of the reasoning behind this changeover, but just in case WW looked less out of place in one application, I wanted to have it on hand.

For the T5 miniature bulbs, I got these super cute one-LED things in several different colors. As it turns out, the dash icons themselves were colored filters, so I couldn’t use all my fancy colors like cool white and blue and Miku aqua and the like – they just looked “off”, or even greenish, which I would not want as a “You have no oil pressure.” warning light… So they became all red, with the exception of the turn signal indicators, which I used the green ones on, and even switching those out had a visible effect on the flashing frequency of the signals (hence why the external bulbs have to stay Analog until I dig out the flasher unit)

I also found out that the high beam indicator appears to be wired directly to a relay, or is otherwise strongly influencing the circuit, because I totally put a LED in that location and then had no high beams. Analog electrical systems…

In classic “Unintentional Van Consequences” fashion, lowering the power draw of the front electrical harness drastically meant the voltage rose much higher…. and blew out some of the tiny little bulbs living in the switches and buttons. Now, these things I am certain are weird and proprietary.

I had to repair these by soldering in small green LEDs and 1/8W resistors. The photo shows an exaggeration of the lighting gradient in the buttons – they’re quite even in color when you look at them.

All of the exterior marker lights are replaced with LED equivalents in the proper colors.

All interior lights were of the 29mm “Festoon” type, but there were few choices in that size, so I decided to go to the 31mm Festoon and bend the contacts out a little. They’ll live.

The “12-SMD” replacement seems to be the most popular in this size, so I got a handful of these in red and white.

The thing I’m most proud of, though, are these “buttheadlights”. I went all-out and wondered what would happen if I replaced the incandescent bulb with something of the same wattage – 10 watts. The answer is buttheadlights.

The reversing and brake lights are type 1156 and 1157 respectively, and I got these for the reversing lights. I actually am now having second thoughts about replacing the brake lights with their red equivalents, because these things are so bright it’s borderline dangerous to someone behind me. I think I’ll plunder some 5W or smaller ones in a similar form factor later.

During my shopping for all of these lights, I discovered they currently do make LED sealed-beam-replacement headlights. I’m not entirely convinced they work well, though, and they’re also still very expensive. Here’s another vendor I was looking at, and these appear to be the “Chinese copy-and-paste philosophy” off-brand kinds.

LED Lessons

There are a number of caveats for those who want to go LED that I discovered in this adventure, and they surround the nameplate rating and physical form factor.

First, shady Chinese parts being shady (but well-lit?) Chinese parts, some of the LED chips seem to be very overdriven or overrated. Specifically, amber/orange and red LEDs have more of a problem with this in my collection than the white, blue, green, etc. This is probably due to the much lower foward voltage of the semiconductor used to make red LEDs (yellow, orange, and so on are based off red LEDs), and the current-limiting resistor being improperly selected. This is hard to fix if the resistor isn’t out in the open, and almost makes switching not worthwhile because of the re-engineering needed

The symptom is lots of heat generation and the LED dims after a while, and some of the wire bonds might even fail and cause one of the dies to go out. The small single-chip T5 lights and the small 1156 sized amber lights I bought have this problem, the T10 size and the “buttheadlight” 9W 1156 lamps did not. This seems to be hit or miss, and so I’d caution people away from buying on the cheap unless you actually do love messing with these things like I do.

Second, you might notice that a lot of these bulbs are way bigger than their equivalent incandescent packages. This is an issue for marker lights, interior lights, etc. where the bezel isn’t very large. At least, you could hold up your bulb to an image of the product and see roughly how much larger it is. Otherwise, you could have to sacrifice brightness for fit purposes.

I got lucky in that the only bulb I bought which didn’t fit directly was the orange front side marker lights, and that was a length discrepancy small enough that I just cut half of the contacts on the circuit board off. But I can’t even imagine how some of those ridiculous corn cob shaped LED wads even begin to fit in their specified form factors. That product right there is my favorite example of “Chinese copy and paste design philosopy” – take what works, then CTRL-C & CTRL-V.

I’m not sure how much more buying the cheap LEDs on heat sinks will help – heat sinks only prolong the time until thermal stress and failure if they’re enclosed in a bubble like most automotive lighting is. That’s why even most home lighting LED products caution against using it in enclosed or recessed light fixtures, because LEDs still generate lots of heat – they’re often cited as “3 times more efficient” than incandescent bulbs or something, but that’s because their luminous efficiency is like 10% instead of 3%. The rest of the 90% is still heat.

I’d say the bottom line here is, I like my glowy cool-white Tron lights enough to shotgun the market and mess with products; if you just want straight up replacements with no hassle, I’m actually not sure what to tell you…

Dragon Con 2014: The Wrapup, or, Operation: I FEEL GASSY, plus Panel Resources

chorl3 Comments

Around this time last year, I said;

I’m back.

Somehow, and not broken down in western Maryland or something

Well, it wasn’t western Maryland per se…. but we’ll get to that. In the intervening week between Dragon Con 2014 and now, resetting the shop from its post-robot season disaster (which immediate followed the post-gokart season disaster) for the fall classes has taken up most of my time.

In addition, I’m seeing to it that the MIT Mini Maker Faire happens! In three weeks, I can hopefully roll out of bed into our own Maker Faire… but of course there’s logistics and administration to figure out before then! If you are planning on being in the area, hit us up.

The story of Dragon Con 2014 begins, as usual, with van stuffing. For expedient access to the panel slides and info, go here.

The one feature of this generation of Mitsubishi Delicas that’s saved me countless times is the squared off rear hatch area. You almost never see this any more with modern “bubble” designs, and even the two other “Van” models of the same era had cut off angular hatches (However, it seems to be making a comeback in the latest generation of Nissan Quest, whose JDM model, the Nissan Elgrand, I like way better).

I can put like 16 cubic feet straight up in the hatch area. A 18″ wide aluminum suitcase fits perfectly, oriented lengthwise, three across and three tall. So basically, the van-stuffing strategy has been, since last year, consolidate everything into suitcases and 30-quart plastic bins, pile as many as possible in the lower half of the hatch, and fill the rest with robots. Überclocker was attached to the rear left headrest the whole trip, using a spare alternator belt looped around it as a retaining strap, while every other bot was arranged creatively besides it.

This time, I stuck to my guns and just kept going on I-81 instead of even remotely thinking of touching the east coast again. Much better time was made – pretty much 20 hours door-to-door. Travelling during the daytime meant a longer sight distance, and consequently, we went faster. It’s been well-proven through the past few thousand miles of road trips that Mikuvan does well either at 65mph or less… or at 75+mph, where the engine is operating in its powerband in 4th gear… guess which half was used more often?

Well, when we could manage anyway. Summer is construction season all-around, and starting from Connecticut onwards south, there was construction and construction slowdowns and delays in literally every state.

After taking most of Wednesday morning and early afternoon to recuperate, we hit up the Invention Studio again, basically the robots & cosplay forward operating base of this whole trip. I began the final assembly of Pop Quiz, which was started the weekend before departure.  I had already done most of the work, so it was literally just throwing the package together. Pictured is the final arrangement of the components before the top was closed up.

I was originally planning on running 14.8 volts with the two 2S 500mAh packs, but some tachometry on the old motor showed me that it was basically 1000 rpm/V. I decided immediately to drop back to 7.4V and 1Ah – kind of a ridiculous amount of battery for a 1lb bot, but it would keep the weapon motor at a sane speed/load and also not make the 6V-rated Pololu drive motors too unhappy.

The batteries are wired in hard-parallel, so if I ever wanted to charge this pack properly, I’d need a two-parallel 2S battery splitter like this.

The two Vextrollers are de-cased and stacked on top of each other using clear heat shrink tubing for insulation. Stuffed right next to it is the 12 amp brushless ESC, which is hardwired next to the Integrated Fingertech Switch.

The Hobbyking 6 channel RX is also de-cased and sits up front, wrapped in electrical tape a few times since I didn’t pack clear shrink big enough. The pins are all removed, trimmed flush with the board except the pins I needed, and tiny 26 gauge signal wires soldered to the remaining stubs. Everything is according to the initial CAD models!

Dense and unserviceable? Yes, definitely, but so are iPhones and I like to think PQ is the iPhone of antweights so………

All packaged up with the new titanium top plate! 15.3 ounces – good enough. It probably weighs 15.300008 ounces up north anyway, so I still qualify for Motorama 2015.

Pop Quiz’s ‘press shot’. Notice the missing forward left corner – by this time, it already ate itself once when I was testing against a scrapped 1lb bot frame. I had ground a radius onto the underside of the blade’s leading edge to prevent this, but on one side of the blade, it just barely didn’t go far enough! That was remedied quickly.

The shorter blade meant that even when it hit its own corner, it didn’t fly away or flip. I in fact didn’t even notice it as an independent event – only after picking the bot up when enough was enough.

Being constructed alongside the antweight work was the latest version of the animatronic RWBY Crescent Rose being built by Cynthia of Cynaesthetics. I’ll let her explain the details, but this was the ‘black project’ that kept me busy over the week/end before we left. I was employed as a CAD mule since I was much faster at using Autodesk Inventor, so I pounded out the design she handed me over the course of probably Wednesday through Saturday.

The crown jewel of this design is probably the red gear-thing on the right. It’s nifty enough to warrant its own entire post. Shown below is revision 1:

It’s a one-shot 3D printed 7:1 compound planetary gear with input and output roller bearings that translates a roughly 16″ circumferential travel (so think 16″ of rope being pulled around it) into a roughly 85 degree rotation of one of the ring gears. The idea was to mechanically synchronize the deploy, though it ended up not quite working because of the difficulty of keeping the two sides synchronized.

There was a great chance that it wouldn’t work at all if I didn’t get the clearances exactly right, such that the multiple solid bodies got fused into one… but they ended up being correct for version 3. It was one-shot printed on the Dimension 1200ES machine in the shop.

Once again, I hosted a few Maker track panels and participated in others. This year’s roster was Maker Resources (my ‘2.00gokart for the masses’ panel), Electric Vehicles, and a new one on Rapid Prototyping Cosplay, hosted with Jamison and Chris Lee, in which we teach the audience how to abuse waterjets. This year, we were smart and stuff, so all the panels are kept on the cloud! Links will be presented at the end section.

Above is my Maker Resources introduction. Yeah, it was about that productive.

Doing some last touch-up on Pad Thai before the Robot Microbattles 1lb and 3lb event. The front armor was too low, causing the front to drag and affecting the bot’s traction.

A clean shot of Pad Thai Doodle Ninja before the event. It only required lifter repair from last year, and replacement of some of the spring steel armor.

A picture of Pop Quiz’s first and only match. The bot seemed to work fine on the smooth Invention Studio indoor floor, but the arena floor was a whole ‘nother story. The bot has maybe 0.025″ of ground clearance on a good day. What does that mean? It could barely move in the arena!

This wouldn’t have been so bad if it were not for the fact that Pop Quiz’s weapon motor was built in 2008. Like, I went and found the blog post that described its construction. This predates even LOLioKart. Whatever I did back then was clearly not up to the bots of today, with the amount of power I’m now running through it. For example, the central shaft of the motor is a small shoulder screw with #8-32 threads, which pretty much stripped instantly on the first big hit, shown above, with “Trash Boat”. This left the weapon motor disabled, so after that, it was just a matter of finding the right floor gouge to get stuck on.

Well, shit. The rest of the bot works great (minus the paper thin ground clearance), so Pop Quiz is going to get a re-engineered motor and a few layers of heat shrink tubing over those wheels!

Due to timing constraints, the ants and beetles were forced into single elimination (again), so PQ left the event 0-1.

Pad Thai went longer in the tournament with Cynthia driving, defeating “Green Reaper” and “Trash Boat” (to whom Pop Quiz lost), ultimately reaching the semifinal where it lost to Jamison’s DDT. The spring steel armor fended off DDT reasonably well, but it was still filled with gouges at the end.

Video of this match, from Near Chaos Robotics.

Besides the front and side armor, DDT managed to get a good shot off at the unprotected rear, which cracked off a portion of the motor mount and sliced up the rear left wheel. The broken O-rings jammed into the rest of the drive and caused one side of the bot to stop working. Luckily, the motor wasn’t damaged!

Pad Thai went 2-1 this time.

Oh god, it’s Monday. It’s the big show. It’s my yearly measure of worth, made worse by the fact that this would be the 10th year since I won a championship at Dragon Con first! No pressure at all, breh. (I won the 12lb class at D*C2004 with Test Bot v3)

No changes at all were made to the big bots at the Invention Studio, since all of the work relevant to them was done before departure.

My Hyperion 1420i charger died mysteriously during Microbattles, so I put out a call to the Robot Battles e-mail list and Facebook page asking if anyone had a charger (or bench power supply) that could charge up to 7S lithium packs (about 28 volts). Dale (of Homemade Robots) brought a 30v adjustable power supply that I ran with during the whole event.

Sadly, I did not run into Dale in either weight class, so we couldn’t do a “10 year band reunion” in the finals….

Test Bot was also at this event, and frankly, it’s never looked better.

Wait, what!? Yes, that’s the old frame and running gear of Test Bot 4.5. I sold it to Mike Jeffries of Near Chaos Robotics about a year and a half ago, and his crew has revived it into Dolos. They upgraded it with slightly larger wheels (one of the causes of its downfall at D*C events, since by that point I’d optimized TB for smooth arenas), a wedge that formerly belonged to Apollyon, and a “bot hook” weapon.

I didn’t get to fight 12 O’Clocker against it, however, since it lost to Dale’s Omega Force.

Setting up 12 O’Clocker for its first match against Served Cold…

During its last match with Tetanus Shot, 12 O’Clocker lost one drive side completely. I thought it was a solder joint or stripped gear in the custom Harbor Freight mounts – Tetanus Shot is an extremely solid bot, so metal on metal collisions are going to have much more pronounced effects.  As it turns out, it was way worse than that:

The motor just straight up cracked out of its mounting holes! Looks like the bottom of the motor mounting screw holes might have been a little too thin. I have spares of the gearcases from last year….

…but of course forgot to bring them for this year.

Well, okay then.

Returning to a classic strategy, I decided to install a zip tie ratchet on the right side. This is a cut zip tie that sticks into the sprocket’s path, so in one direction it gets sucked into the chain and locks that side up. In the other direction, it is pushed away and the side moves (relatively) freely.

I used this method a few times in years past with Clockers of Lesser Drivetrain Reliability to great success, for tenuous definitions of great. The bot could move forward, in a wide circle, and then pivot about one side in reverse. 12 O’Clocker is still a relatively formidable opponent even in this limping mode, this time exemplified by how many times I still managed to get Tetanus Shot after the installation of the ratchet…

12 O’Clocker made is 1 and 1, winning against Served Cold and losing to Tetanus Shot. By the 12lb Rumble, it had also cracked the motor off the other side, so I started and stayed mostly in the center of it to smack as many people as possible while avoiding the edges. A drive-disabled 12 O’Clocker somehow managed a one in a thousand alignment with Omega Force, and I literally threw it overhead off the stage.

I edited together all the video I had of 12 O’Clocker and have it uploaded onto my Youtube channel. Here it is for convenience;

(This is in addition to the Near Chaos 12lber playlist).

I’M HAVING FUN GUYS. I SWEAR. NOW GET OFF MY CASE.

Überclocker was the big hit of the show this time, going straight through with no losses and winning the 30lb championship. There’s nothing wrong with the bot right now – I can turn it around to Motorama 2015 tomorrow. The Banebots wheel swap proved to be an extremely good idea – Clocker had a traction advantage that was clearly noticeable in its matches with Nyx, against which I’ve always been neck and neck in pushing ability.

I also entered Clocker in the 30lb rumble, with some… additions… to epicly hilariously results. 90% of this event to me is a chance to let loose and be silly on stage with robots, so we took the spare pool noodles that we brought for safety covers – Jamison’s Bug Loves Robot and Überclocker both rank pretty high for pointy ends on bots – and straight up taped them to the bots for added entertainment.

I edited together all of its matches here. Near Chaos has a much better view of the bedlam that was the 30lb rumble.

Clocker’s performance was nothing short of stellar, and I’m glad that it finally works reliably. I don’t anticipate making any performance upgrades or changes to the bot at the moment. The top clamp arm actuator still has a bit of a habit of coming apart – it didn’t at this event, but it was looking close by the end, so I’d like to actually drive some screws into its mounting brackets before Motorama.

12 O’Clocker is a different story. Besides the whole motors-breaking-off issue, which is a design problem with the gearbox, it needs an aspect ratio more similar to Überclocker to be more effective. Right now, it’s dopey and cute looking with its short wheelbase and tall frame, but it translates into poor lifting performance since the center of gravity has less leverage. It’s more likely to faceplant than lift (but that makes it cuter and dopier!). But again, I’m not sure if I’d change this, since the point of it was to be silly and fast – two things it’s good at, at least!

I ran out of time this DC season due to helping with the RWBY weapon that I couldn’t really do justice for Pop Quiz and Pad Thai. Pop Quiz’s concept is sound, but that motor needs to be updated to 2014 standards! It’s been a while since I’ve made a motor, so I’m kind of itching to do it now… Oh, and throw a few layers of heat shrink onto the wheels. Pad Thai suffered plenty of body damage this time around, but none to the lifter – it was actually kept down most of the time  anyway.

The Con Elsewhere

Once you go to one Dragon Con, you kind of get the idea: it has neither rhyme nor reason, nor a theme such as comic books, Warhammer, or indie video games. It’s ALL of it. As a result, I’m always on the lookout for new and innovative crossovers and takes on media franchises. Seeing a group of Iron Men gets old pretty quickly, for example, but nothing really prepares you for…

Iron Totoro. The picture doesn’t do justice as to how huge it was, which was easily 3 people wide. There was a hotel security staff just off to the left escorting it through the (very tightly packed) Marriott hotel.

Interactive costumes are another cool feature of a convention where you’re not expected to stay within a certain industry or franchise. Here is Mr. Fingertech Robotics himself, Kurt, with hand-mounted reed switches that could sense high fives. The large LED screen displayed the current count (yes, double high fives work!), and the LED strips on his vest would change color depending on how many high fives were accumulated in a certain span of time.

I forgot the exact count, but he was well over 10,000 by the end of the weekend, and it was a huge hit just walking through the hallways.

Cynthia’s mechanical scythe posing next to a more artistically complete but non-mechanical one. RWBY is stll a series which is gaining traction, so not too many people recognized it immediately, but the mechanical deploy caught quite a few eyes. It was presented at the Rapid Prototyping panel (which also featured Jamison’s big hammer and a few other things) to great fanfare. Version 3 ought to be even more exciting…

So that’s Dragon Con 2014 in a few pictures! I’ve already made plans for next year, including changes to the panel format and possibly more collab panels. First, I’ve always thought that Dragon Con panels were supposed to be 1.5 hours long, since at other cons the panels are scheduled in 1 hour blocks. As it turns out, it’s supposed to be 1 hour of panel and halfn a hour of room clear/reset. What?! I totally only found this out when Val, the Robotics & Maker track director, had to toss everyone out of the panels I ran or participated in…. because I thought the content was going to fill about an hour and 20 minutes or so. Whoops.

We hustled out of Atlanta under the cover of early morning darkness, and followed the same I-81 route back.

Panel Resources

This year, I did a smart person thing (only you guys say I’m smart, I never said anything to the effect…) and made/kept the presentations online. So here they are:

  • Maker Resources 2014: Updated with new content, vendors, and internet memes!
  • Rapid Prototyping 2014: In collab with Chris Lee and Jamison Go. If the subset of people who 1. read this blog and 2. have pictures or video, I’d appreciate it greatly if you sent it our way. I think this panel was highly successful.
  • Electric Vehicles 2014: In collab with Adam Bercu. This was primarily a picture show since we actually did a panel thing and talked the whole time.

Operation: I FEEL GASSY

Well, this sure looks familiar.

Nope, it’s not a repost!

Around 9 in the morning on Tuesday, near the VA/NC border (by a little town named Lambsburg, as I found out), I stopped to pick up a full tank of gas from a Loves Travel Stop. Roughly 1 hour later, south of Roanoke, was when we noticed the first hints of power loss, but we assigned it to the fact that the region was mountainous. Shortly after Roanoke, in the span of less than half an hour, I went from keeping up with highway speed in the right lane to crawling at 25mph on the shoulder.

Realizing this was patently unsafe, I pulled off near Natural Bridge, VA onto U.S. Route 11, which was a much slower local road, while we tried to formulate a battle plan. At this point was when I was beginning to think that the problem was with the fuel system. The symptoms were:

  • Lack of power at mid and higher throttle. The engine could idle and run at low speeds and loads just fine, but as soon as I gave it more gas, it began sputtering and losing RPM. By itself, this could have indicated a problem with a clogged or restricted exhaust or intake.
  • I could rev the engine in neutral freely if I depressed the throttle gently; but a sudden mash of the pedal would cause it to sputter. Something load-dependent was the issue.
  • More surprisingly, though, it was inconsistent. During the various start-stop cycles at red lights and when the engine was off, the restriction would seemingly go away for a short time, but then almost immediately return afterwards.
  • When it was away, I could drive and accelerate normally. Something was moving or shifting, possibly by gravity/engine suction or pressure, or perhaps temperature, into place.

We went on U.S. 11 until Lexington, VA, where we stopped for lunch at a Taco Bell and waited for the engine bay to cool off a bit so I could possible look inside. I picked up half a tank of gas from an Exxon station, where I also checked the air intake and filter in case a squirrel actually got lodged in there or something. You  never know.

It seemed to behave normally right after the fillup, so at this point I was highly suspecting some kind of gunk or contamination in the fuel. I milked what leftover power it had for several more miles until the problem came back again, halfway to Staunton, VA

Realizing we were never going to make it home if this kept up, we stopped at a rural gas station halfway between Lexington and Staunton (in a town called Raphine)  where Adam and I dove under to extract the catalytic converter (after half an hour inside a Burger King waiting for it to cool) and to inspect it. This resulted in the following hilarious picture:


Let the shipping begin

After taking about 20 minutes to drop the catalytic converter, we found there was absolutely nothing wrong with it or with the pipe downstream. At this point, I was pretty damned sure it was fuel-system related.

We decided to play it safe and try to ask for an ‘expert opinion’, which involved a bit of calling around seeing if there were area mechanics we could limp to. We visited two – one was right across the highway, was actually a truck and RV repair shop, and run by a very friendly and wise old guy whose name we didn’t catch, but whose business was named Cash’s so I’m going to call him Mr. Cash, because that shit’s cash.

After taking a test drive, he agreed with me that it was most likely fuel related, but seeing as how this was already late afternoon and likely nobody in the area would have the needed parts, could only offer me a bottle of fuel system cleaner and some good luck. Mr. Cash recommended we visit another shop around the corner, King’s (which I assume is run by Mr. King), to get a second opinion.

Mr. King himself was welcoming but busy, but the mechanic he foisted me off to was absolutely convinced it was a catalytic converter problem despite me telling him already what we’ve taken apart and checked. I’ll give the guy some credit – they were busy when we walked in, and we were likely not going to stay and pay them to do service, so I can’t imagine I was very high on their priorities list. We left after deciding our welcome was outstayed. Certainly, if you walk into the IDC while I’m busy putting out student go-kart fires (maybe literally, mind you…) and started asking laser cutter questions, I would have responded similarly.

At this point, I decided to see if the ECU was possibly outputting any codes, since 1989 is just new enough that some sort of electronic diagnostic was mandatory. One problem: I didn’t have the diagnostic sheet from the service manual that told me what the blinking voltmeter needle did.

Solution: I found it on my own website – posted from last year, an exact snapshot of the page I needed. See, kids? This is why you blog everything, even if you don’t think it’s important!

I continued north on I-64/81 to wait for the problem to return while Adam carefully stared at the voltmeter. Sciencekart is funny, but I wasn’t about to try and stare at the voltmeter while driving for real. However, even though the problem returned, and I was reduced to shoulder-crawling again north of Staunton, VA, the ECU didn’t throw any errors.

Really? I figured it should at least return “Fuel Pump” or something, but nothing. Modern ECUs can tell you if the fuel-air mixture was even a little bit out of expectation, but the diagnostic system on Mikuvan is not sophisticated enough for that.

I coasted into Weyers Cave, VA – between Staunton and Harrisonburg – and we limped to the Shenandoah Valley Regional airport. At this point, Cynthia and Jamison needed a way to get home because they have things like real lives and jobs. They picked up a rental car from the airport, since there were no direct flights to Boston from here.

The battle plan was prepared. Adam and I would crash overnight with his friend in Richmond, VA, then return in the morning with a U-Haul and trailer. From there, we’d basically be running the original Operation: MIKUVAN again!

In what I realize must have looked like a broad daylight car theft, we pulled into the airport parking lot with the truck and trailer and pulled back out with Mikuvan loaded in under 10 minutes (Keep in mind it was still capable of moving under its own power, just for not too long, so I just drove onto the trailer). If we tried this in Boston, we’d been surrounded by black trucks and assault rifles in a few seconds, but they seem to be more chill out here.

The destination was a shopping center south of Harrisonburg, VA, with multiple big box home improvement and auto parts stores in the area.

And so, for the second time in two years, I found myself in a town with “Harris” in the name, under a U-haul trailer, in the parking lot of a big-box store, fixing a van.

The plan of action was to remove the fuel filter and then connect it up backwards, then use the fuel pump to empty the whole tank through the backwards filter. Ideally, this would knock out and wash enough particulates for us to gently nurse it back home, still 12 hours away. Pictured above is the first shot of fuel from the filter. Delicious.

Every few gallons, we’d switch the 10 gallon fuel can for a water bottle and inspect the fuel for clarity. Even at the end of 4 shots, there were still tiny black flakes and bits coming out of it. I know this is probably the past 10,000 miles of deposits, but regardless, it was rather surprising to see how contaminated and full of other substances gasoline, allegedly a highly refined product, can be even in 2014. At least, I’ve never dealt in any way with “bad gas” on any vehicle… but perhaps it’s because I’ve not personally put 10K+ miles on any one vehicle before now.

We dropped the bad fuel off at an auto shop, fully fueled Mikuvan with some Shell premium gas (I was paranoid okay?!) and went on our way. The trip back to Richmond, about 2 hours, would be the test – if I could manage this fine, then it should be okay for the rest of the trip: all of the instances of the fuel restriction would appear with 15-20 minutes of driving each time. I took the lead on the return, with Adam following in the truck and trailer. If the problem returned, I would slow down, pull behind him, and just Grand Theft Auto it onto the trailer.

Around 9:30PM on Wednesday, we rolled out of Richmond and headed north on I-95. I drove at a relatively constant speed and throttle, trying to maintain 70mph, until north of York, PA, upon which Adam took over and got to White Plains, NY on I-287.

I think I should drive with a clogged fuel filter more often, since I got the best mileage ever during that leg. Problems started returning around White Plains, more mildly but still noticeable, so we decided to play it safe and took CT-15 northward instead of I-95.

Here’s the story in a Google map.

CT-15 was a scenic but rather chaotic (being morning rush hour in the NYC metro area and all…) drive. We discovered new Tesla superchargers:

In the span of time we were taking a break at this station – like 20 minutes at most, three Teslas rolled in and out.


Hey, is this still under warranty?

An hour south of Hartford, I got the idea of calling area Mitsubishi dealerships to see if anyone had a fuel filter for an obscure model they likely never personally sold. I’m not sure why I thought this was necessary by this point, since Hartford was but a hop, skip, and faceplant away from Boston, but I was kind of tired and delirious anyway.

Hartford Mitsubishi (& Cadillac & Maserati) was extremely helpful – their parts guy was on the phone with me for 10 minutes trying different models to see if any parts cross correlated. I know for sure the same style filter is used on late 80s Monteros and Galants, as well as shared with the Dodge compact pickups of the same era…. but all of those are virtually extinct by now too, so no luck with those specific models. He ended up finding a ‘universal’ style that fit across model lines. I’ll take one.

We decided not to do the filter swap just two hours outside the finish, so the rest of the trip was spent hovering in the right lane on I-84 and I-90 to very little drama. I made it back onto campus around 1pm on Thursday.

analysis and recourse

I was not expecting “bad gas” to be still a thing in 2014 – sure, I’ve heard stories from other people, but come on, this is the future where we live in the cloud and download our food and movies alike through 4G LTE. I was also under the impression that fuel filters, like any filter, will show symptoms gradually, and not be fine on one hill, but completely go to shit by the next. The filter in question was installed after I got the engine working again in May 2013, and it’s been completely trouble-free for all of the trips since then. It was even trouble-free for 550 miles of blasting in and around Atlanta, where I was regularly pushing 80mph. It was trouble free for the first six hours of the trip, which featured much of the same hammer-dropping. It’s difficult for me to not mentally assign blame to the Love’s station, since I picked up a full tank of fuel from them and then the engine totally went to hell within an hour and a half.

It also seems getting recompense from a gas station is quite difficult.

First, a bunch of people would have to complain AND specifically point out they were the cause. Who knows, maybe the 6 other cars at the station with me when we refueled in Lambsburg also had issues some time down the line, or could have them very shortly after a few hundred more miles, but their owners will just chalk it up to the 5000 mile oil change interval running out and take it into their mechanic, never noticing the cause or caring about the final invoice.

Second, even if they were also broken down somewhere, normal people wouldn’t do what we did: we didn’t do a single thing “the legit way”. Instead of calling for a tow, calling my insurance company to find an authorized shop, getting said shop to perform all the diagnostic work we did, and paying for the replacement part in labor, we slum-fixed it ourselves outside of The System. The “tow” was a U-haul, the “shop” was the parking lot of the Harrisonburg Home Depot. I guess I did end up buying an official dealer sourced part? What this means as a whole is I don’t have an ‘official’ paper trail to back all of these claims up.

I called Love’s and they looked into the store in question, but of course got back to me with “Sorry, nobody else complained and our tests showed our fuel is clean, so we can’t help you”. Of course nobody else complained and your fuel is clean – that’s what your job is to tell me, so I ain’t even mad.  If I were to file a lawsuit, then I’d be potentially out a few thousand dollars and many months of staying on top of it, while swimming upstream against “well, nobody else complained, so what the hell is wrong with your car then?”

Oh well – unless one of you have a better idea, I’m just going to cut my losses at a few hundred bucks, pay off Jamison and Cynthia for their rental car expenses, and file this one under “Don’t Trust the System”.

I took care of the fuel filter in an hour outside of MITERS last week, and based on my (admittedly relatively short) trips around the Boston outer regions, there’s been no problems at all. Maybe it’s time to hit Vermont again for another Ford Fusion battery just to test it on the road for more than an hour at a time, because the New York Maker Faire is next week and I’d certainly like to avoid stranding 5 random freshmen on the side of the road in Connecticut.

Speaking of which, stay tuned for the work on that so far – Chibi-Mikuvan needs some pretty mission critical repairs! Time to switch vans once more….