Archive for June, 2013


The Successor to Melonscooter

Jun 30, 2013 in Melon-scooter 2, Project Build Reports

Ah, Melonscooter.

The unsung hero of my vehicle fleet, it’s the one that actually works most of the time and which putzes me back and forth day to day. It’s a mish-mash of unmatched parts and on-the-spot engineering built on top of a scrapped commercial scooter frame, which has been operational with only a few small service gaps since 2010. Like any vehicle that is more tool than project, it’s also been slowly backsliding partswise as things wear out and I replace it with whatever the hell I happened to have within arm’s reach. For instance, this past few months has seen it devolve from the melon (C80 motor) to an SK3 59mm motor as I realized the bearings on the Melon were slowly becoming powder:

Then, one day in February while pushing through leftover snow, the timing belt disintegrated again – Melonscooter has never seen very good belt life due to me using the HTD belts at way above their safe rated power – and this time I had no spares. So naturally, I devolve even further to chain drive:

The wheel and chain were spare items purchased for that term’s 2.00gokart class.

About the same time, the front of the frame near the steering neck broke a weld and developed a crack. I rode it like this for a while, being extra careful to not put too much load on the joint, and eventually welded it back.

Sadly, Melonscooter finally succumbed to a combination of poor Chinese metallurgy, years of New England road salt, and probably my welding. One day in May, I thought the ride was getting a bit jiggly for some reason. As I pulled onto a sidewalk to investigate, this happened:

Well then. This isn’t very productive.

I’ve been swearing to rebuild Melonscooter on and off for the past year or more, but like a certain other somewhat rusty vehicle is now, it’s just continued working. The entire joint area appeared to have rusted out – I didn’t see it only because it was well covered in paint. The failure propagated clearly from a crack (though not through where I welded).

By this point, the top plate was also cracking from sun exposure, the headset bearings had lost their cages and shields, and I already had another giant hole in the battery box (from going over some sidewalk too excitedly a long time ago) which was becoming its own rust problem.

So I took this as a sign that I needed to move on. While 2.00gokart was wrapping up, I haunted the ever-powerful Craigslist for a cheap donor scooter, electric or otherwise. A week later, I found this thing:

What is it?! A blurry dark picture in someone’s garage and the tagline “scooter $50″ or something to that effect led me, on one of the very first long-distance Mikuvan missions, to this thing. It’s an “X-treme XG-505“, which demonstrates that convoluted alphanumeric naming is not exclusive to the domain of motorcycle manufacturers. Either way, it’s beefy as hell – the steering neck joint on this thing will clearly never fail in the same way. The giant deck is solid 3/16″ aluminum, and the frame is 1/8″ steel plates and what looks like .075 wall steel tubing. It also has dual disk brakes.

Basically, a great (if huge) candidate for chopping up. It was also not running, with engine trouble.

This sounded entirely too familiar, so at the risk of betraying my electric brotherhood, I immediately began tearing the engine off and stripping the frame, readying it for electrification appraisal.

While tearing down the electrical system consisting of a starter battery and related circuitry, I discovered the world that is scooter starting solenoids. They’re basically miniature contactors (slash high current relays), and could be useful if you need something between a 30-40A automotive relay and a 300+A full size contactor.

Starting solenoid also means electric start. What I also found is that the 49-50cc engine kingdom can be found with electric starts that are pretty damn cool – 4 brushed, neodymium magnets, basically like tiny Magmotors Ampflows. The downside is they are often shaftless, being designed to mate to the engine crankshaft.

Still, I do want to mess with these and see what they’re capable of.  I was going to tear this engine down further to extract the electric start, but someone else already called dibs on it so I didn’t want to leave it permanently disfigured.

If you want to mess with these parts, I’ve basically found then using combinations of search terms like “49cc 50cc electric start” or “49cc 50cc solenoid” or similar.

The teardown continues! Did I mention this thing is enormous? The wheelbase is a good 4 or 5 inches longer than melonscooter, which is already pretty long to begin with. If I want it to fit in the same places as before, I’ll need to do some creative basket mounting. I am, of course, designing a basket into this one from the very start.

The last thing to do before I could crack my CAD knuckles was to remove the engine mount. This was done with some selective angle grinding. The engine mount actually stuck through on both sides of the deck’s rear portion; the part on the bottom I couldn’t reach with a cutting wheel, so I literally had to grind the entire thing down to flat – as the result photo shows.

With the ugly metal pectoral fin gone, I began to size up the new “stern deck”, characteristic of Melonscooter, that would also mount the motor and be a splash guard and milk crate holder. The frame’s rear forks are just vertical 1/8″ steel plates with a flat plate in between, but it was very much the wrong width to reuse the old aluminum one from Melonscooter.

While it would have been simple enough to remake the aluminum deck in the correct width, I decided to make a bent sheet metal housing instead. I figured as long as I was most likely going to need to make sheet metal structures for a certain future electric derpy van (temporary or otherwise), I should get some practice. Fast forward to after I was completely done with being occupied by 2.00gokart:

I hopped into the Inventor sheet metal mini-game and, using some crude measurements made with a tape measure and straightedges, whipped up this protoform stern deck. Now, when I say sheet metal, I actually meant 12 gauge (0.1″) steel.  Yes, this is some serious sheet metal. It is, however, the same thickness as the rest of the plate steel on this frame, there’s no additional frame that will be on the underside (e.g. it’s entirely structural), and there could be a few dozen pounds bouncing in a milk crate suspended off the back sooner or layer, so it not only had to be structural to mount the motor, but also rigid in bending as a result.

I think I could have gotten away with 16 gauge (roughly .060), but my intuition is calibrated to working with aluminum and I sure as hell wasn’t going to put 1/16″ aluminum in this application. And I had a 24 x 24 plate of it already chilling in the shop. The other reason was that I could easily mock this up with some 0.1″ thick paperboard stock I also had. This was someone’s laser cutter feedstock, but they left an entire 3 x 2 foot panel of the stuff in the lab.

So using my crude measurement model, I made a paper version and tried it on the frame:

This crude-model-to-cheesy-prototype stage showed me what dimensions were sane, what needed a little bit of changing, and what was totally off base. It turned out the major dimensions were reasonable, so I only had to adjust here and there for looks and clearances.

Back to the CAD world to add mounting features for the motor. The two holes up top are for an eventual basket clamp I have in mind. Those ventilation grates will make sure some airflow is directed over the motor, so it’s not just spinning inside a hollow box.

This little piece adds some more rigidity to the very rear of the deck and also functions as the other component of my eventual basket lock.

Adding some lightening to the other side of the deck which doesn’t need to hold the motor. All of this will be waterjet cut, bent into shape, and then welded.

Like so. Notice the additional slots and edge nibbles that are on the folding edges. Inventor automatically “unfolds” the metal to a 2D cuttable form for me, but I wanted an easier time bending the steel, so I added the slots right on the edge of where the bend is supposed to start to “encourage” the metal there. The triangular nibbles tell me to align them exactly with the teeth of the bending brake.

I used the Giant Brake of Certain Tibial Fracturing in the FSAE/Solar Car machine shop to push this metal around. The machine is pretty clapped out and uneven, so I stuck to one side as best as possible. If I find myself needing more intense sheet metal fab, I might take a stab at repairing this thing too. For now, push-lever-metal-go-bendy is enough.

And the final piece fitted onto the rear with some clear tape. I accidentally left the teeth too far away from the edge of the brake for the last fold – the one with the grille on it. That’s why it’s inset a little from the edge of the side flanges. Fortunately, it was not a disastrous mistake.

Up next: Actually welding this sucker to the frame, and where the hell am I going to put the batteries? To also feature an extensive DERPDRIVE update, since it, too, involves tons of metallic hot gluing.

A Mikuvan Subproject: Operation DERPDrive

Jun 25, 2013 in derpdrive, mikuvan

I’m going to take a quick break from being too sissy to start on rust repair work to begin a thread for something which has been planned since the beginning when I got the damn thing. As I keep telling myself (I swear this is still true), the end goal of this project is to fully electrify Mikuvan with a Siemens 1PV5135 motor, Azure Dynamics DMOC645 inverter, and a stack o’ batteries from everyone’s favorite undead alphanumeric battery company. When I bought the van in non-running condition, this seemed like an immediate possibility; at the time, neither I nor anyone on the trip were auto mechanics, just your average Battlebots-buildin’, scooter-ridin’ hoodrats.

Well, now that it’s running just fine for some reason, that enthusiasm has been admittedly damped a bit. Taking it out of commission now to drop the engine and transmission out would mean potentially months of MITERS no longer being able to haul hundreds of pounds of shelving and materials on a whim:

We can’t have that, now, can we. But I’m a little too heavily invested parts-wise in this project to never let it see the light of day.

Here’s the trouble: There is a gap of about 1 mile between the shop with a 2-post lift and my actual, legitimate parking spot for this thing, with a rather steep garage entrance ramp in between. I can’t hog the lift or the patch of space underneath it for months on end while working it, and I would hate to ask for a tow or push from someone else every time it needs to move. If electrification started in earnest, there will definitely be a period of time when the vehicle will have absolutely no remote possibility of moving under its own power.

From the start, I pondered ways to real quick rig up a temporary electric drivetrain that could exist wholly independently of the vehicle and basically jam itself under it to move it gingerly around. Ideas were thrown around ranging from what basically amounted to a two-man push-assist made with welding wheelchair motors onto a stick, to hijacking the rear driveshaft directly and basically going parallel-hybrid. At times, the thought of seriously manufacturing a “car tractor”, like a smaller aircraft tug, marketed towards shops and yards was considered.

What I didn’t want it to become was a science project of its own. It had to be quick and dirty, existing just to scoot Mikuvan in the dark of night between shop and spot. It could move at 5mph for all I care – it had to go all of 1 mile, but it had to have enough torque to shove the whole thing up a roughly 20 degree slope.


I consulted the low-orbiting cruft cloud that is the N5x complex and came up with a few candidates for this job.

  • Basically gluing a power wheelchair to it. 10″ wheels, 24v motors upped to 36 volts, and basically 5 miles per hour it was. I had my doubts that the motors would even have enough thermal load capacity to make it that mile. It would definitely be easy. The downside? Not even theoretically enough torque to push the thing up the entrance ramp to my parking garage, and I won’t be able to get enough speed out of them to take a run at it either.
  • Eteks everywhere. Between all the electric vehicle shenanigan hotspots, there must be like five brushless Eteks (now known as Motenergy ME0907s). One would have been more than enough power, but it would require external gearing (slash chain drive). I also don’t have a brushless controller big enough to make this worthwhile.
  • Cap Kart-Van hybrid. The giant D&D sepex motor (Hey guys, how fucking hard is it to give me one damned web catalog with all your motors on it? What is this, 1993?) of the legendary Cap Kart was dismounted a while ago to be used as a dynamometer load by someone that said something about solar cars. Like the fate of many projects at MIT, it never got remounted, and has been sitting on a bench since. This thing, a D&D ES-101A-33 type, is pretty much capable of moving a Geo Metro or something independently, with a peak power capability probably north of 20kW.

Controllerwise, I mined up a working Alltrax DCX500 from the defunct Vehicle Design Summit group, whose materials have been slowly diffusing back into the building’s various tenants. Running at 48v and up to 500 amps and paired with the D&D motor would make a respectable power system on its own – and certainly one hell of an pushing attachment. Parallel hybrid is looking reeeeeal good right now. Needless to say, this combination, with its appeal to my sense of unnecessary overkill and having just the right amount of potential disaster, won the appraisal round handily. The power source would be taken care of by one of the prospective alphanumeric battery modules – we’re not talking Model S class driving range here.

I also scavenged back from MITERS one of my old 11″ (real) go-kart wheels which was going to make it onto the never-built Super LOLrioKart back in the day. At this rate, I might as well just hang Cap Kart, whose carcass is hiding in a corner, off the tailgate and be done with it.

I ran some quick numbers and found that the D&D motor would only have needed around 4:1 of gearing to shove Mikuvan straight out of the garage while pulling 500 amps. Unfortunately this would have also resulted in a go-kart-like speed of about 45mph once I was done with exiting. Appealing, but I would also like to avoid piloting something without power steering or braking at those speeds. An 8:1 reduction would cut the speed to around 25mph with the ability, given enough traction, of shoving Mikuvan straight up a wall. Now, 25mph is plenty to keep up with traffic and have nobody notice that something might be a tad off.


The next question was where to put this complication. For that, I turned to the underside where my spare tire was hiding:

Emphasis on was – the spare tire was basically the first thing I removed and disposed of since the rim was almost completely rusted out. Dismounting the tire and hanger uncovered this pristine area between two parallel frame rails in the back – the “#6 Cross member” and “Rear End Cross Member” according to the manual. These things are (as it turns out) monocoque construction but with a discrete frame structure, so it’s not totally unibody like modern minivans tend to be.

Here’s a better look from under the lift:

(It’s also the only spot on the underside that isn’t covered in filth.)

This spot seemed to be begging for a weird action movie attachment to be installed in it. It’s located very close to the rear axle, so I wouldn’t need to build in tons of compliance and “suspension” travel. It’s out of the way of the possible design and manufacturing exercise up front. And parallel frame rails.

The only downside I could see was that I might want to hide the Siemens motor in that spot some day, but I think by that point I’ll have a justifiable reason to leave it on the lift for a little while. That, or give it a nosewheel.

The dimensions were also pretty handsome:

The width between the rails was 15″, with another 10″ ahead of that before the rear differential bulb. The rail depth was about 3″ and the distance from the underside of the floorpan to the ground, with the vehicle parked on a level surface, is 18″. Width was pretty much arbitrary.

the mechanism

I spent a while musing about what kind of mechanism to mount everything with, and how to attach it to the frame. I didn’t want to weld anything in (making it permanent, at least from my traditionally welding-free building methods), and wanted to avoid drilling and bolting if at all possible.

Not knowing how strong the spot welds holding everything together actually are, I decided to pursue a jacking type of attachment. The structure of this device would push itself against the two frame rails hopefully with enough strength to resist the loads of the motor cranking on it. This was going to have to be a very strongly braced connection, since I’m basically mounting a fetal twin EV to the underside.

If it turned out that I was going to pop welds or bend sheet metal, I would just bail out to drilling and bolting using blind insert rivet nuts into the frame rails.

I began by hopping into Inventor and sketching out what would basically be going on:

I made the basic mechanism in a sketch, first using lines only (or just the essential “bones” of the mechanism), then fattening it up with representative motors and wheels. In this graphic, the big circle is the 11″ go-kart wheel and the smaller circle is the D&D motor.

At this point I’d basically settled on making most of this contraption from welded steel tubing. My usual modus faciendi is to waterjet-cut some plates and throw them together, but I’m guessing that the majority of fabrication on the final vehicle – motor mounts, battery boxes, additional structures, etc. – will be welded, manipulated steel sheet and plate joined to tubing, so what better than to practice?

The mechanism of raising and lowering is an extremely simple single-swingarm, almost like a motorcycle rear end, with what would be a “shock absorber” in a real vehicle application being an adjustable leadscrew. That way I can crank the wheel down and continue loading it against the ground to take weight off the rear axle.

And this mechanism in the lowered position.

With the basic mechanism loaded in my head, I started embodying it in 3D. This is the tube structure that will be welded up. 2″ square tube make up the swingarm, 1″ square and 1×3 rectangular make up the framework. All 1/8″ and 0.1″ wall – in other words, 1,000x more heavy duty than the van itself. I’m fine with that – this shit is cheap.

Using the 2D sketch mechanism info, I transferred mounting holes to the 3D model. The four holes are mounts for some beefy pillow blocks to hold the wheel driveshaft and the intermediate shaft needed to complete the 8:1 mechanism in two stages (I can’t achieve that in 1 stage without going to ridiculous sprocket sizes)

I’ve moved onto adding models of the D&D motor and wheel. The dimensions are obtained from calipering the real world items.

Added pillow block models and also one idea for performing the frame jacking. The pillow blocks are giant cast iron jobs from Surplus Center – maximum cheapness per bearing.

The jacks are giant turnbuckles used in reverse to provide compression force. But wait, aren’t turnbuckles only designed to add tension to a system? Yes, hence the hugeness. The long skinny sides of turnbuckles make them ill-suited to pushing against a load – they’d rather buckle apart. I figured that making them enormous would mitigate this issue for the clamping forces I’d need. These are 10,000 lb turnbuckles from McMaster, who fortunately pried a CAD model from the legacy U.S. company that is making them so I did not have to drop $70 to find out otherwise.

I wasn’t too set on the returnbuckle idea, but for the time being I settled on the rest of the mechanism and assumed a jacking method will exist.

Turning my attention to the leadscrew linkage, here’s some shots of the trunion design. The trunions will be made of some chopped up 1.5″ diameter steel tubing with welded endcaps. The nut in the center there is a standard 3/4″ Acme steel nut, the kind you use to hold steam valves together, and again purchasable on Surplus Center for a guava and two potatoes.

The underside is where it gets a little interesting. So here’s what’s going on – As the wheel contacts the ground, the blue spring will compress with every further turn of the leadscrew, adding “preload force” down on the wheel. If the wheel hits a pothole or something, or I drive off the entrance ramp, it can dip town and maintain traction, avoiding awkward fake burnouts.

If I need to crank the wheel back up, then the J-shaped hook applies pressure to the backside of the swingarm trunion (the long round tube in the center) and so the whole assembly can float back up. When the spring is compressed, the hook moves away from the trunion a little.

What this doesn’t do is add upwards compliance, say a speed bump or armadillo in the road (because Cambridge has a wild armadillo infestation issue – ask any long time resident). However, the path I intend to take is pretty free of obtuse bumps. If the wheel hits an obtuse obstacle, the forces should be transmitted handily into the ladder frame. Should be. Those insert nuts are looking delicious right about now.

I knew coming back to the previously handwaved mechanism would make me smack myself for even thinking of it. Here is a new jack design made only of welded tube, threaded rod, and nuts. $150 cheaper and probably less shady. The forward (right side in the image) bar is free to move in and out of the tubes, kept from moving in only by the two nuts jamming against the tubes. If I need to expand the width, then I just crank on the two nuts.

This design was frozen after a few days of not looking at it, during which I instead watched the Singaporean students try to design kart drivetrains using 4,000 RPM/V motors. Which, mind you, is totally possible if you don’t mind using a 100:1 gearbox or something, but your handling could suffer.

construction begin

Here’s the pile of big parts as of last week. Motor, sprockets, bearings, a bunch of related hardware…

…and this pile of steel, primarily foraged but also ordered from Speedy Metals. The huge shafting, in 3/4″ and 1 1/4″ sizes, came from Surplus Center to match the bearings.

Why such huge shafting? It’s because as it turns out, 1 1/4″ is a standard American go-kart wheel axle diameter. I found a cheap hub on eBay which matched the wheel perfectly and converted it to a 1 1/4″ shaft.

I’m guessing the 32mm standard size is the Irritatingly Close But No metric size for the same application.

I also tried something a little different sprocket-wise this time. I normally waterjet my own sprocket profiles, but with the assemble-from-COTS-parts mantra of this build, adapting them to the drive shafting would have meant that custom flat plate sprockets were pointless. Instead, why not buy commercial flat plate sprockets? From Surplus Center, large sprockets get cheaper as you move to these “welded hub” versions. For $20, you can basically have any sprocket size and hub bore/feature combination. The final output sprocket, of 50 teeth, gets the huge 1 1/4″ keyed bore, and the smaller intermediate sprocket will ride on a 3/4″ keyed shaft.

I’m going to spare the welders the pain of seeing my handiwork, but let’s just say that “MIG-over-TIG” was an acceptable ditch plan. It’s often said that in TIG welding, the best welds look like a stack of coins. Mine look somewhere closer to a stack of rabbit droppings (Part of the problem, as I remembered/was reminded, was that I was trying to weld these sections using a 100 amp TIG welder and a tungsten too small to even take that current).

With the parts buffered and ready, it’s time to attack the structure itself. There’s much welding metallic gluing ahead; the next post will focus on the construction of the structure and machining all the little round things that go into it.

In typical fashion, I spent a few minutes thinking of ways to name it as close to an Internet meme as possible, and the result is Detachable Electric Rear Powerdrive , or DERPDrive for short. I wish everyone the best while facepalming.

Also, I found a nice sample of first Legendary Derpy Van, the Toyota Van, while cruising through Cambridge back streets avoiding traffic one day. If only vans were like dogs or guinea pigs.

Loose Odds and Ends from the Past Week or so

Jun 19, 2013 in Beyond Unboxing, Electric Vehicle Design, mikuvan

Things have been getting exciting in the last week or so as the SUTD Summerkarts Global Leadership Program students have arrived, and we’re now well under way into the Silly Vehicle design phase all over again. Global Leadership Program. That’s such an epic name for 2.00gokart, guys. To be fair, there’s plenty of other things going on for the students too, most of which are ‘leadership’ flavored. In this running of the class, since I’m not being watched over by The Department and need to make sure everyone has paper lab notebooks, the student groups will be blogging their builds! I’ll post a list of links once everyone gets set up.


I’m currently at 380 miles.

Having essentially reached the limit of things that have been going wrong, I’ve been faced with no choice but to start attacking rust. This thing hasn’t even so much as hiccuped a single time since Operation: Bad Timing. I would say that at this moment, having checked everything I think is important, I’d trust a trip out to at least New York City (about 240  miles).

I’ve mostly been spending the past 2 weeks psyching myself out and picking up some materials.


Based on estimating the clooooouuuuuud Internet and asking friends, I got a pile of things from Eastwood – panel sheets, a bucket of sealer, and some rust converter. I was skeptical about the “rust converter” – it allegedly converts iron oxide (“rust”) to iron phosphate or iron tannate, which is some shit I’ve never heard of and only appears in product descriptions plagiarized from Wikipedia. This sounded shady, and success seems to be hit or miss. However, it’s relatively cheap, so we’ll see what this magical potion does. That, plus another haul of random abrasive and sheet metal banging tools from Harbor Freight, ought to round out the basic non-sketchy rust patch. I’m going to try the pound-and-weld-metal route – falling short of soldering since it sounds a tad too hardcore at the moment – instead of throwing fiberglass at it.

All that, and waiting for several days of hot and dry weather to do the majority of the work, just to smoke out any residual moisture from the body holes. Recently, it’s actually been hard to come by, with the Northeast in its Periodic Random-Ass Storm Season (PRASS). There’s no point in tying a puddle up inside my work. Worse come to worst, I’ll point a space heater at the trouble spots for a day before doing anything.

What I’ll do first is probably do all the sanding and grinding; the full-depth investigation, basically, and then post it publicly to get some opinions and appraisals. The idea is to cut or grind off what I can get to, covert and cover over what I can’t abrade off, and then slather external underbody repairs in sealing compound. I also managed to find a matching Chrysler color at Advance Auto Parts to repair the exterior paint afterwards, tested by blasting random areas and staring at it a few minutes later. This may backfire horribly.

Part of the reason I’m hesitant to start is because I have the feeling that things will get more and more Death Race 3000 if I mess something up or discover more structurally unsound areas than I previous anticipated. What you can’t see….

Though, in the limit of Death Race 3000 style modifications, this thing will probably look more and more like a classic wedgebot.

testing the mini-jasontroller

I replaced the full-size caseless Jasontroller in RazEr REV2 with the mini version detailed last week.. I’m definitely a big fan of these now – they’re basically the same as the full size, in a much more useful package.

This is the smaller controller uncased and fully cleaned. I essentially took out every wire I didn’t need, and also locked the speed setting to high internally by jumping the right side orange wire; by default, the “3 speed range” switch comes in the medium range, which means it divides down the throttle input) This has no bearing on its upper speed limit which is still around 540-550 eHz or so, but for low speed motors the throttle response will be substantially retarded otherwise.

These controllers have a discrete logic power switch, unlike the full size Jasontroller, so I also hardwired that internally (left).

I discovered that the entire controller case fit inside the space where my old full size Jasontroller went, minus one corner. So, instead of redrilling the mounting holes for the smaller heat spreader bar, I cut the entire case into an L shape with the board resting in its stock location…

…shrink wrapped the whole thing, and Velcro-mounted it in. Clean and waterproof, and the additional aluminum should still offer some thermal capacity.

The overall height of the controller when stripped of its case is under 0.8″ (in my configuration, it’s not much shorter due to the existing case outline remainder), which opens up the potential to be stuffed into even more things.

I’ve noticed no difference in riding behavior between the mini-Jasontroller and full size, once again confirming they’re basically the same thing. I’ve noticed some slight difference in starting behavior – the mini doesn’t twitch backwards, at least not often. More observation will be needed to discern the differences. In the mean time, I’m officially qualifying the mini-Jasontroller as Certified Legit. You can buy it on this page, and maybe soon from Equals Zero. If you make something using one, post it!

I’ve added this controller to my Scooter Instructable in the EV controllers section.

more silly rideable things

One of the downsides of having 160 cubic feet of self-motive cargo volume is Oh man, this free stuff on Craigslist looks awesome. I’ve previously been limited by what I felt like carrying back on Melonscooter, or worst case, ride back independently. That’s no more.

What you see here is a most-relevant-to-my-interests free Craigslist haul of two nonfunctional electric bike (-like-objects) from a closing e-bike shop. The one on top, as it turned out, is quite the machine. It’s a TidalForce IO cruiser bike, from another one of those small EV companies with an illustrious but ultimately short lived existence, in complete condition. The bottom red pile is a generic Chinese “电动车” or “Chinese moped”. These are sold here and there under various names (here’s one example, and most likely the company that retailed it since it says GREENPOWER on it!). Its condition was a little more beat up, but seemingly just devoid of batteries.

Here’s a better shot of both of them. Being me, I’m actually more a fan of the little red moped – it’s a little weirder and has that Chinese charm to it, but the Tidalforce was much more complete, so I began messing with it first.

The backstory of this machine was that the customer dropped it off for battery service and abandoned it. Apparently, these bikes were notorious for having their NiMH cells degrade very quickly.

Lacking a legitimate charger, I jacked it in on a power supply to 45 volts CV and fed it at about 0.8 amps for basically the better part of a day. The cells inside are nominally 8Ah, so the charge rate is a nice C/10 trickle charge. In case any of the cells were permanently toast, it wouldn’t cause thermal runaway. The battery came off nice and warm, and I rode around until the bike shut down from undervoltage. This charge lasted basically 5 miles with very little pedaling. The original advertised range was 15 or 20, but according to the storytellers realistically 6 or 8 miles, so it didn’t seem that far off the mark.

The termination condition is dictated by the battery management system onboard, and this is where things got difficult. No matter what, I couldn’t convince the charge-o-meter to go above 20%, even when I’ve clearly left the battery on slow trickle for many hours! I suspected that this artificial BMS meddling is what shut the bike down in the first place, since it didn’t feel like it was about to slow down.

I did some research online and came upon this useful page for decyphering the onboard controller for the bike, as well as this flamewar thread on Endless Sphere where someone mentioned that the battery needs to be discharged to under 32v to resynchronize the charge indicator.

This battery is too damned smart. I couldn’t get any output voltage from it unless the bike was on, since it has internal FET switches to shut off the cells from the pack output, so I couldn’t artificially drain it. And even at 44 volts off the charger, I couldn’t get the bike to move more than a couple dozen feet before the BMS shut me down. I hate it when batteries are too smart – I’m forced to crack them open.

Off the front wheel comes. It’s on a quick release, so a latch and some cable pulling later and it comes cleanly off.

Removing the case screws and side, check out this holeaphobia-inducing lotus flower of cells! The terminals all had bits of corrosion on them, but there were no signs of leakage that I could observe.

Hammering on the opposite side of the wheel makes the entire battery structure fall out. This is the important side of things – the BMS board. My mission was to artificially brick the pack via the CELL tabs, draining them to under 32 volts, hoping the BMS would reset or something.

I used this shady arrangement of power resistors, totalling 15 ohms, to drain down the pack over the course of about 3 hours, getting the whole array down to about 30v. Afterwards, I immediately closed everything up and threw it back on the charger. It did exactly jack shit.

The battery meter blinked 20% the whole time! I’m going to guess I did this wrong somehow, or more likely, forgot that Ni batteries bounce back in voltage very well after an initial discharge. By the time I was done connecting things back up, the battery voltage could have been well in excess of 32v, making the BMS think everything was still skullfucked. But it should at least recognize the 7Ah I dumped back into the battery, right?! No such deal.

As of now, I’m currently riding this thing around day to day to burn down the charge in a useful fashion. Apparently, the charge meter blinks in its entirety when the BMS reset point is reached, so I’ll hopefully be ready then.

Why am I trying so hard to use this proprietary-ass stock battery when I could very well just hack the “B” battery with any number of potential long running packs? I’m hesitant to do that because I don’t actually like this thing. It weighs nearly 60 pounds and is enormous, clearly built for a much Manlier Man than I. Plus, I can barely stuff it inside my front door. I guess I’m used to smaller and more portable scooters which can be rolled inside – this sucker is going to need the bike rack. Not really my style.

For now, though, it’s alive and working as yet another Craigslist impulse that turned out to be a little neurotic but otherwise livable day to day. What’s with me and that kind of thing lately?

Let’s move onto the Little Red Moped.

After diddling around with the TidalForce for a few days, I decided one night to get this contraption running along with Adam. I cleaned up the mechanicals and repaired the existing wiring while he created an impromptu brick of 12V7 modules I have on standby for the summer EV design class.

Look at that beautiful… 20 gauge? wire going to the hub motor! This machine is capable of Real Power.  The hub motor appears to be a 48v, 500W (or 750W) brushless type, like this.

Unhitching the electronics box, I discover this wad of wires. If you ever wonder what Jasontrollers and their ilk are actually used for, this is the answer. As you are reading, millions of Asian moped bros are cruising about on machines exactly like this one.

During my wiring cleanup, I found a spider!

Someone clearly was derping around with this after-market and the controller is likely not the original. Someone was also terrible at this. There were plenty of examples of wires just twisted together and electrical taped up, and solder joints like that.

Whatever. It worked, and all I really did was replace some of the decomposing electrical tape and resplice some of the signal wires appropriately.

With the impromptu 48v battery and a random found bike seat, it was ready to roll!  And roll it did. The acceleration was brisk and utilitarian, and the suspension was a bit underdamped but compliant even when riding up curbs. It’s very quiet, and there’s a pedal assist sensor which almost sent me into the wall a few times when I instinctively kicked the pedal out of the way.

Riding it in this form makes me envision myself wearing a straw hat and dark brown Mao suit, riding along a dusty Chinese road to my factory job. With a cage of chickens on the back to be sold at the market later that day.

We agreed it would be more amusing once completely rewired and running on 72 volts, but sadly, Mao’s Little Red Moped did not see that day. For at Swapfest, I was riding around aimlessly for no more than 10 minutes before someone bought it off me on the spot. Sans batteries, but still.

So my net wheel gain for the past few weeks has been 2, both won by the TidalForce bike. Unfortunately, that may increase again, because I’m considering…

a playmate for mikuvan

Your job, Internet, as the guardians to my sanity, is to tell me I do not need another one of these.

Let’s face it. I was originally looking for a science project with Mikuvan, but elected to put in an honest repair effort to have me some of that thar “auto tech” larnin’ y’all kids are into these days. But now it’s running too well, and a few of us are basically invested emotionally in it, and I have a harder time with the thought of tearing everything down again than when it wasn’t running.

Mere weeks after I stated my life goal Passive Non-Career-Derailing Desire was to collect the Legendary Van Trifecta, I discover that I might have a chance to nab the rarest of them all: the USDM Nissan Vanette. Yes, the one which was well known for lighting on fire.

The back story for this find is quite circuitous indeed. It wasn’t by weeks of stalking Craigslist, or a “Hey, I hear you like derpy vans” referral from my “Hey, I heard you like trashy electric scooters” network. Instead, while doing research on the other members of the trifecta, I found this Jalopnik post for a Nissan Van (-shaped-object) in North Carolina. Some link hunting led me to the original sellers album…from 2011.  Out of sheer shits and giggles morbid curiosity, I emailed the seller what amounted to “lol do you still have this”. MFW the answer was yes:

I’m at a loss about what to do.

On the one hand… Whoa, a chance to capture the rarest Legendary Pokévan and train it make it the base for this electric drive project. After all, the way the world apparently works, as I’ve handily found out in the past few months, is you have a functioning car, then you get an explicitly nonfunctional one to mess around with. This van is so explicitly nonrunning the FCC and ASE are about to join forces to erase it from reality. The chassis mechanicals appear to be comparatively rust free (then again, so I thought with Mikuvan).

The downside? Space. Parking. Not even counting the (once yearly) cost of registration and (fairly low) monthly insurance premiums once it’s operational, there’s no such thing as a little empty grassy patch to stick a nonrunning vehicle here. I was lucky with Mikuvan that my one allotted parking spot was open. What I cannot justify is paying hundreds of dollars a month for a parking spot or garage space for a van-shaped lump without the knowledge that I will immediately be able to attend to it, rare or not.  I’m currently in the process of exercising my social network™ to see if anyone is willing to put up with my bullshit. Ideally, there’s a back alley of a nearby industrial space somewhere that I can slip into, or someone’s back yard who thinks this is all too hilarious. I’m not going to try very hard.

So the dilemma goes. I will probably not see one of these in such a complete condition for many years, but maybe in said years I’d be in a better position to start Big Chuck’s Van Adoption Service.

 (All pictures above of the vehicle were provided by the seller)

I’m filing this post also under Beyond Unboxing since so many things were taken apart in one way or another.

Beyond Unboxing: Mini-Jasontroller, 8-FUN Bike Hub Motors, and Other Goodies from ELifeBike

Jun 12, 2013 in Beyond Unboxing, Reference Posts

Whoa, hey! Haven’t done one of these in a while, though I’ve definitely taken apart a host of things recently that should be written up. I’m doing this now because, as usual, I hope I’ve come upon a useful source of parts for both my own projects and those of anyone else who considers themselves connoisseurs of fine sketchy electric rideable implements. This time interval’s report brought to you in part by Jamison, who I’m glad to announce has joined the ranks of us MIT hoodrats and has been pulled out of the south to become a dirty Yankee. Though, given that he is from Florida, was probably always one to begin with.

The foundations of this chapter of Beyond Unboxing began several weeks ago as Jamison was completing his melonscooter-equivalent, Guavascooter. For the record, the Collegiate Silly Vehicle League nomenclature for the SK3 59 series of motors is guava, following in the 80mm C-series (e.g. the C80/100 and C80/85) being the melon and short melon. Always on the hunt for new shady Chinese vehicle products, Jamison informed me of the existence of what is basically the most shady Chinese parts supplier website I’ve ever seen: eLifeBike.

I think the engrish on the shopping cart software alone is the source of 20 new inside jokes in our crew up here.

What struck awe into me is the sheer absurdity of the prices. How the hell are they so low? What is this stuff actually made of – recycled human hair and potato starch like everything else from China?! We were interested particularly in their line of 6-FET controllers, which seemed to be in the same bloodline as the revered (…) Jasontroller. According to Jamison’s report, it seemed to behave basically like the Jasontroller, but was about 60% of the volume.  Seeing such other joys as $66 hub motors and $28 battery chargers, I decided to front some money to offer, once again, to the Gods of Silly Rideable Things. I went ahead and bought said $66 hub motor, a “250W” model; two of the 24V 250W controllers (basically equivalent of the Jasontroller model I buy the most, which can actually run up to 40v reliably), and a 10A 36v battery charger. If any of this stuff so much blinks when I turn it on, I’ll be happy.

As usual, with these exclusively Chinese vendors, the base price is deceptive. Shipping on items can often reach $30-50, if not more! After a week (Fedex International Priority was somehow the cheapest shipping option), I found out why the prices were so low:

Paddy Fields Street? Damn, is this just some guy working out of his straw shack in the middle of a field of rice? Turns out if you Google Maps the postal code 518108, it’s a small industrial neighborhood in northwestern Shenzhen (are there any other kinds?). Given the name, it probably used to be paddy fields.

Here’s all the goods! I can confirm that, at least superficially, they are made of metal and have wires sticking out of them. So I’ve at least gotten these items discerned into one of two categories: small bombs, or electric vehicle products. As far as the NSA is concerned, it’s all the same anyhoo. Hello NSA!

I ordered a 36v 10A charger because most of my daily commuter tools run 36v (or 38.4v) electrical systems, so at least one of ‘em ought to benefit from this quicker charger. My currently fastest charger is 5 amps.

Let’s start with this hub motor. As everyone probably knows, I am a purveyor of fine hub motors. This style of hub motor is generally known as the “8FUN” or “Bafun” or “Bafang” motor. In the 250/350W size, they’re around 6″ diameter and are designed for bicycle front wheels, to offer pedal assist and not explicit propulsion power. I’ve been eyeing them for a while, since they are readily available on the Internet of Things, but never sprung for one until now.  Since I’m not a big bicycle person, I’m of course interested in how to adapt them to drive smaller wheels such as scooter wheels, or some kind of robot appendage. Or vans.

8fun motor

Six Phillips-head case screws layer, the 8-FUN motor is cracked open. This was suprisingly pleasant and easy.

The observant might note that, in a divergence from my hub motor designs or those of full-size e-bike motors, it’s a geared motor! That’s right – the outrunner style motor on the left actually spins on the stationary center steel shaft, and it has a steel pinion which engages with…


…gears in the planetary gear set.

Alright, hold on a second here. Somehow, the Chinese are able to turn a few lumps of dirt, a rock, and maybe a cup or two of oil into a beautifully machined cast aluminum case, ball bearings, laminated steel stator, neodymium magnets, copper wire, internal and external gear teeth, and laminated lacquer-coated iron stamped shapes, then sell it to me for all of $66 (which is not that much these days, considering the steadily rising Chinese RMB exchange rate)…

…but use PLASTIC gears  to complete the great circle of e-Bike life?

I would have gladly paid 10 cents more for some sintered steel, guys.

All over the Internet, the weak link in these motors and the source of much frustration are those little blue (or off-white, or black) nylon gears. The design itself is quite robust, from my appraisal, besides those damned gears. The gears ride on common 608 skate bearings and are retained solidly to the carrier by snap rings, so they never rub on the motor. Typically, small planetary gearboxes just throw you a big wear washer for the gears to mash against and be done with it.

A little more table-bumping and the other endcap pops off, exposing the backside of the motor. The construction of this motor is pretty solid. A full circle of magnets, tight airgap, and an actual PCB that holds the Hall sensors. By itself, this motor is worth the price if I had a specific application for it. It’s extremely utilitarian – for the same price, you’d get a much smaller but much shinier R/C aircraft motor. One of the product lines I’ve wanted to a start is a line of extremely plain, Brutalist styled motors which aren’t all chromed out and sticker-plastered, but, like, actually do work.

In this motor, the stator is rigidly fixed to the shaft, and the can has a short bearing section in it which rides single-supported on the shaft. Not unlike a huge version of Pop Quiz’s weapon motor.

Closeup of the gearset. The motor pinion and outer ring are all metal, but the planetary gears are PLASTIC. Count on the Chinese to cut the 1 corner that would make the product actually worthwhile! The gears seem to be metric module 1, a common size, so perhaps similarly sized metal gears already exist for it – I haven’t done extensive research into this facet of Chinese e-bike parts, since I’m not heavily involved in the crazy e-bike hacker community.

It’s interesting to note that the carrier has an integrated freewheel. That way, you can pedal-power override the motor’s propulsion force. I, for one, actually hate freewheels and like my motor inertia to be a continuous function.

Closeup of the motor, showing the workmanship and method of stator attachment to the hub. The winding-bindings are a nice touch.

Overall, fuck plastic gears I think this is a pretty solid product if you run it within its ratings – basically 350W limited power systems for pedal assisting. And in this application, I’m sure it rocks hard or the design wouldn’t be commonplace, but fuck plastic gears I definitely don’t see much overpowering potential in it due to the fuck plastic gears.

I don’t have an application lined up for this little thing, so I put it back together and just ran it on a table for kicks. It’s very quiet – surely the plastic gears gear-like substance helps with noise absorption. However, one thing Jamison and I talked about, but I have yet to investigate, is whether or not this motor is small enough in diameter to jam into other cored-out wheels. Instant DIY small hub motor!


One of the things that caught my eye when Jamison popped the top on Guavascooter was how small the controller was. It was advertized, yes, as miniature, and I should have look at the size specifications. But the real kicker was when I pulled out a spare Jasontroller:

The QQ 6-fet series is basically a hair more than 2/3 he volume, with the best decrease being on width. The standard 6-FET Jasontroller is 105mm long, 35mm tall, and 66mm deep, compared to 100mm x 30mm x 52mm.

Here’s my Sciencing Rig all set up with a SK3 motor (feat. Sensor Boards). I neglected to take a close-up of the board inside, but the construction is of much higher quality than the corresponding full size Jasontroller. More smaller SMT components are used, resulting in a tighter board, and – my favorite part – the FETs are mounted to the heat sink bar much closer together and at the very base of their leads. There’s no gap between the FET body and the board, so the whole assembly is not wobbly. But it also means I couldn’t just fold back the FET rail to read the part number.

After some very careful light and mirror tricks, I, in my classic habit, found the FET part number: the RU7088R. A bit better than the usual offerings!

As far as I could tell from inspection, the circuitry is exactly the same as the full size Jasontroller, and the chipset is also the same (X8M06-C with a comparator frontend for sensorless operation).

This controller has no “auto-train” wire. Instead, like the full size Jasontroller, any existing motor Hall sensor mapping is erased if you run sensorless. Then you plug in the (hopefully well-placed) Hall sensor rig and run the motor again to full speed, back to zero speed, and cycle power. These things are smarter than I am.

And like the full size, it also has a roughly 550Hz commutation frequency limit. The shown waveform is 15.625kHz PWM frequency on top of the commutation frequency. If the motor wanders above this speed, unlike the full size Jasontroller it doesn’t keep beasting current into it, but rather it shuts down. Upon return of the throttle to zero, it can start up again. So, it seems to be an improvement – instead of grenading itself and your motor, it soft-kills.

550Hz-electrical translates for most 7-pole-pair outrunners to 4714 RPM maximum (550 times a second / 7 electrical rotations per mechanical rotation, then * 60 seconds per minute). Hitting the “3 speed selector switch” into high speed made no difference – again, it’s a processor limit. Sadly, these processors seem to be using their internal oscilltors, so it’s nontrivial to overclock. If the oscillator were external, you could potentially just make it faster.

In summary, for most purposes, the mini-Jasontroller is exactly the full size, but just cuter. The smaller package means you can shove it into many smaller vehicles (specifically scooter frames) where it would otherwise be unwieldy.  I’m an immense fan of these things already, but need to get in some more hardcore testing and detonate a few before making a decision on recommending them. But if you’re interested, you can get one from eLifeBike for about $38 minimum (66% of that price is shipping alone). As the purchase quantity approaches infinity, the price appears to settle close to $14-15 a unit. Yes, I tested this on their Engrish-laden cart software.

These two controllers I bought might end up on Chibikart2 for robustness testing.

This concludes another chapter of Beyond Unboxing! If you end up using any of these generic Chinese EV products in anything, feel free to drop a comment. The reason I love to mess around with these parts so much is how care-free they are. There’s no proprietary system or brand or manufacturer’s artificial limits to deal with, the price is right, and they work. One of my beliefs is that the next big EV revolution is quietly taking place in China: the millions of these nameless e-bikes carrying people and goods every day publicity-free, while we scurry around with shiny, low volume, tax-break subsidized people-bubbles built around big money personalities.

(There go my chances of working at Tesla or any other electric car company, ever.)


The Weekly Adventures of Mikuvan: Operation I-Fixed-Too-Many-Things-At-Once-To-Give-It-All-One-Smarmy-Name

Jun 06, 2013 in mikuvan

As you can see, I’ve already given up on my promise from last time. Or perhaps I didn’t?

When last week wrapped up, I had just finished replacing my front right wheel bearings. On the immediate agenda was repairing the front blower motor, which seems to have gone dead long ago, and I was getting pretty desperate because this past weekend was an early heat wave in the area with temperatures in the low 90s°F. I had already verified that the (resistor based ;___; ) speed regulation circuit was fine with exception of the lowest speed, and that the motor did not respond to direct 12v input.


Like Fanvan. Do you remember Fanvan?

In the Official Derpy Van Strategy Guide, the heater unit had its own dedicated disassembly page:

As you could imagine, it was not very helpful. The gist of it was basically

1. Disassemble everything.

2. No, we mean it. Everything.

The entire dashboard structure had to come out. Not to mention, even, that the step page before this was to disassemble the heater control unit linkages (the things which deflect air to select heat or A/C, floor or … face? vents, etc.)

In my usual style, I suspected something was amiss and that there must be an easier way. Basically what the past few weeks of pretend-automotive-tech has taught me is that everything in a vehicle may have an ‘official” repair procedure, but Raúl and Jimmy at the shop up the block most likely have figured out a way to do it quickly. My plan was to be Raúl as often as possible.

For me, the possible quick route was an in-situ replacement of the fan motor’s brushes.

The motor, for the record, is the little silver can with the round nub near the lower center of the image. Keep in mind all this is well hidden under the lower dashboard. What you’re seeing is me aiming the camera up from the footwell, with the lens under the brake pedal and the flash unit above the brake pedal. The metal rail that dips down in the foreground is the throttle pedal.

After staring for a while, I determined through empirical trials that I could reach my arm under both pedals and up to the motor, leaving just enough space to wiggle a stub Phillips head screwdriver to undo the rear brush cap screws. To get into this position, I would have to extend horizontally out from the driver’s side footwell, facing the base of the driver’s seat. In other words, totally away from the repair point, and the entire repair is to be done by feel. I wish there were pictures of this whole process as it was happening, because it was truly one heroic position.

So why on earth did I think I could just pull the brushes? Typically, in a robot motor, you don’t replace the brushes at all – if they’re gone, that’s it, and the motor is done. More expensive and larger robot motors make it such that you can just remove the brushes by themselves, one by one. Being derived from industrial motors, that’s how the typical robot motor is put together, and it’s what I’m used to.

However, automotive motors tend to be a little modular if they’re not designed to be disposable. I obtained this replacement blower motor online, and was curious as to the internal construction, so I popped it open. Two screws later, the entire brush plate was dangling from the motor commutator for dear life. It turns out I could replace the brush plate as one assembly. A little more research showed me that this is incredibly common for major automotive accessory motors – starters, for instance. Most little motors like power windows seem to be disposable.

Discovering this was basically what led me to think that in-situ repairing the motor was a good idea. Typically, the brushes will go first in a DC motor if it is otherwise mechanically sound and well-lubricated. Being that these automotive motors are basically made of reinforced concrete and solid cast iron stamped steel everywhere with big sintered iron-bronze bushings that last forever, I was betting hard that the brushes had simply disappeared and the rest of the motor was sound.

Here’s the brush assembly removed. Now, if I had just pulled the plate out without thinking much, the brushes and springs would have escaped and scattered very quickly. Drawing from past experience disassembling robot motors such as the venerable EV Warrior, I prepared a Round Thing of Brush Retaining and slid the brushes onto it. The round thing was just some random rubber bump stop discovered in MITERS, besides which I was conveniently yet illegally parked.

When I Assumed the Position and removed the two brush plate screws, this is what fell out at me.

Hey! I didn’t know they made these vans with brushless fan motors! That’s pretty cool, and is just a testament to the legendary reliability engineering that the Japanese put into thei…

I digress. What you see is a small pile of chocolate-flavored cocaine carbon brush fluff where brushes should be. This stuff must have been micro-scale fine. When I blew on this pile, which was caked to the inside of the steel back plate, it generated a cloud of dust completely disproportionate to its original size.

So this confirms the hypothesis that the motor brushes were just toasted.

The harder part was getting the new brush cap back on. I basically only had one shot to do this, and any misalignment or dropping would result in the brushes and springs disappearing forever into the dark crevasses of the dashboard. To facilitate this, I made a doubly-aligning Round Thing of Brush Retaining from a spare bronze bushing. The ID of the bushing was bored out to just over that of the silver sleeve behind the commutator (measured on the spare motor and then increased just a little for margin). That way, if I can get the thing roughly aligned at all, the sleeve will help with placement. The OD was just barely larger than the commutator, which was good: as soon as I push the brush caps off, they should land on the commutator.

And here was what I was dealing with, getting that brush plate rig back onto the little copper nub there.  I was concerned enough about this process to actually simulate it on the spare motor with it sitting around a corner (out of sight) and me wiggling the brush plate through feel alone. I wanted to make sure I knew exactly what the features on the motor back felt like. I “dry ran” once or twice with the old, used brush plate to make sure I could snap the board’s mounting bushings (little rubber blocks) in place.

And after a heartstopping OH MY GOD THE BUSHING IS FALLING OUT moment, the new brush plate is in. Notice the blue things sticking out of the motor now.

Now, I have no victory pictures or videos of this repair, because it’s a fan for crying out loud and the only thing in the video would be a whooshing sound. But it worked! I ran the fan for a little while on low (2nd) speed to seat the new brushes.

I did have a new resistor block, but that one was located too far down to even get a screwdriver into. I tried for 15 minutes with putting bits on universal ratchet joints to no avail. Whatever, I’ll live without the lowest (generally not very useful) fan setting.

After this repair warranted a victory lap to Advance Auto Parts for even more brake cleaner, I came back and took apart the left front wheel to check on the bearings and clean everything up.

This time, I didn’t replace them. The rollers and races did not appear to have any wear or damage, so I just re-stuffed it with grease and torqued it back to spec. I know you’re supposed to symmetrically replace bearings, but I was not in the mood to pound on the races one more time. Again, we’re assuming I don’t grenade everything within 10,000 miles (I’m currently up to 230.)

So what’s next on the list? The next day was a little less intensively hot and I initially brought Mikuvan out to get the Massachusetts state inspection done, but it turns out they really want you to have a front license plate. I was issued two plates, but it was never made with a front license plate holder; and no, stuffing it on the dashboard apparently didn’t count. I was turned down by 3 area shops that I drove around to.

Whatever. I’ll rig up a fix later. For now, let’s rewire the radio.

This post brought to you by K2 Energy. That’s the brick I dissected powering an AC inverter which is running a small soldering iron. Inefficient conversion of power, yes, but I neglected to pick up a cordless iron or butane powered crack torch iron so it’ll have to do.

The van came with a cheap but reasonable modern head unit with CD, aux jack, USB power, and SD card slot, but it was wired incorrectly. I could only get the thing to turn on if I had the ignition in the ON position *and* the headlight switch flipped to accessory/daytime lights. Yes, both. This made no sense whatesoever.

But after reading the electrical manual which is far more helpful, I found that the main power was wired to the dashboard gauge lights (hence requiring the headlight switch to be engaged to accessory) and the backup power was wired to to the ignition switch! That would explain why it never remembered stations or equalizer settings when the key was out.

A quick rewire later and I was in business. The sound system on this thing is truly a product of the 1980s. No highs, no lows, and not even Bose at that. There’s no subwoofer by modern standards – the sub is a small, roughly cookie tin shaped box affixed to the front console’s underside. There are no door speakers, probably because the doors aren’t thick enough to put any in. I’m fairly certain my old $25 computer speakers had better clarity.

Alright, with the sound system now playing a horrifyingly hollow rendition of Vocaloid Dubstep playlist, it’s time to start moving towards the rear. Next on my impromptu list was to repair the center row seats.


For the uninitiated, the center row seats in the 80s Japanese Van Squad could all spin around in a circle, but only the Mitsubishi Van had them on a set of beefy drawer slides so they could also be shifted front and back. Basically, my two seats combined have more degrees of freedom than a Segway. You pull a latch and it unlocks the mechanism (a big steel locking crossbar mounted on a spring which catches in slots in the slides) and move until the mechanism snaps back into another slot elsewhere.

The trouble with mine was that they were stuck in eternal drawer slide mode. The mechanism was jammed or broken, so for the past few weeks I’ve actually been stuffing toolboxes and milk crates of parts in between the seats to hold them in place. Friends going on van adventures were told to brace themselves or be sectioned neatly by the seat belts.

I don’t have any pictures of the mechanism or the underside of the seat. Why? Because as soon as I undid the 4 bolts and started lifting the seat, the mechanism popped back into place.

Well how about that. I decided to not press further and dissect it – instead, I slathered the whole thing with spray-on lithium grease and also thoroughly greased the track. It has yet to be a problem again.  I surmise that someone pulled the worn mechanism too hard and caused the locking bar to pop out of its guides, becoming stuck in the loose position.

I confirmed this suspicion by tugging really hard on the handle and trying to move the seat – at least once, I was able to stick the mechanism. But with the path now greased, a hard slam into one travel stop put the locking bar back in its place. Should have tried that to begin with…

I performed the same jiggle dance to the drivers side center seat.

The seats can lock rotationally in only two positions – full front facing or full back. The mechanism is just a pin-in-a-plate kind of detent stop, so I have half a mind to waterjet a new one that has like 15 degree increment clicks or something, for maximum hilarity.

license to print

All this being said and done, I was still out a front license plate holder. The cheap and hacky way would have been to just drill some holes in the bumper and screw it on. When I was at one of the local garages, I saw someone with this and it was perfectly legitimate.

But surely there’s a better way to do this than machining my exterior. There’s two hidden bolts in the grill-like slit on Mikuvan’s from bumper which I decided to take advantage of.

I don’t know about this solution being “better” so much as “lol a 3d printer” when a bent piece of aluminum would have sufficed, but I whipped up this solid ABS license plate bracket holder in a few minutes and set it running on the Lab Replicator™. The post coming out from the front is a designed-in support structure to hold up the ceiling of the counterbored hole which the bumper bolt will reside. The hole around it is large enough to slip a 1/4″-drive deep ratchet into.

The finished bracket adapter with the artificial support post removed with some wiggling.

Nobody will ever know that it wasn’t OEM!

Now that it’s CERTIFIED LEGIT (until June 2014, anyhow), I’m slowly running out of problems to solve. It just means that soon, I’ll have no choice but to tackle…

The rust.