Anyways, as previously announced, Operation: BAD TIMING went down Saturday, and I am proud to say that it was a resounding success; the sound you hear is a hilariously lawn-mower-sounding 4 cylinder Mitsubishi 4G64 powering a vehicle which resembles a normal American minivan, just with the nose belt-sanded off and a few corners hit with a deburring tool.

Here’s the story of what all came together on a bright, sunny Saturday afternoon in (a basement in) Cambridge.

The scene of the crime. A few days before, I went to the neighborhood Harbor Freight and invested a very low 3-digit sum in a 3-ton hydraulic jack and 3-ton jackstands (among other handy accessories). As someone who has used HF equipment for years, I’m fully aware of the need to de-rate everything Harbor Freight tries to sell you by 50+% in order to use it safely. Especially on a matter which would probably reduce me non-consensually a few inches in thickness if the equipment fails. The van weighs 2910lb (1.5 tons, basically) empty, so 3-ton everything it is. Jackstands were placed according to The Official Derpy Van Strategy Guide – there’s a convenient round frame rail on the underside that fit the stand cradles exactly, almost like they anticipated people doing this or something.

The jackstands enabled free access to the underside of the vehicle in order to release several engine cover/timing belt cover bolts, and to release the lower transmission cooler and radiator coolant feed lines.

To get to the timing belt, the radiator and all accessory belts and pulleys needed to come off. This stage was basically done by Official Strategy Guide and some finger-feeling. The service manual doesn’t show some steps, figuring you know this stuff already.

For instance, the only step in radiator removal was “RADIATOR”, not “Remove these 2 bolts, this hose, and this other hose but from the underside of the car, and drain the transmission first so you can also get these two other hoses. Oh, by the way, the radiator shroud doesn’t clear the main cooling fan, but it will if you yank hard enough so you don’t have to take these 4 other bolts out.”

Yeah. That’s how you do it. “RADIATOR”. We decided that yanking was the best way.

After the radiator was wrestled out, I started attacking the fan and fan clutch. This right angle T-handle drive ratchet came in handy immensely for many of these tasks – among others being a makeshift impact wrench and hammer.

Leverage was used to break the fan bolts hold, then the T-handle used to quickly extract the bolt. There was no space to actually put the electric impact wrench I bought in there.

One of the fan nuts needed some Vise Grip Assist to untighten. It didn’t make it back onto the fan hub afterwards. Surely 3 bolts out of 4 is enough…

About midway into the disassembly process, and all the accessory belts have been removed.  The next stage was to remove the crankshaft accessory pulley, which was another 4-bolts torqued way too tight. I actually had to have Adam counter-torque me through the camshaft pulley (holding a socket wrench locked the other direction from my torquing) and rock my own wrench back and forth to break it loose!

After the accessory pulley came off, a few bolts later and the timing belt cover could be removed.

…and this what fell out as soon as we did that. A ball bearing.

Not a good sign.

As the cover was removed further, several more ball bearings fell out. This was not looking good.

A shot of the front of the engine with timing belt components exposed.  The lower left, short timing belt is the balance shaft belt, to be replaced along with the main timing belt. Its tensioner was actually pretty intact. The main timing belt, however, was a different story.

The tensioner is a “offset cam roller” kind of thing mounted on a swinging, lockable mechanism. The mechanism, a single steel stamping, was just fine. But where the hell is my tensioner?

Oh, there is is! At least, that’s the inner race. The actual tensioner roller itself was freely jiggling around inside the timing belt case. It seems that the bearing disintegrated long ago, scattering balls everywhere inside and causing instantaneous and likely fatal timing loss for the engine.

I purchased a full timing belt components kit, so it came with the 2 tension roller assemblies and belts. This is the new balancer belt assembly.

Bear in mind I was not the person taking the pictures, or you’d likely have gotten a picture of the main tensioner roller with every ball bearing recovered and piled on top of it. Others are not so OCD about photos as me, so for now, enjoy this picture of the lettering on the timing belt.

And this photo of nothing in particular. You can kind of see the new (green shielded) tension roller for the main timing belt installed. Much carb cleaner was used to make sure the mating surfaces and pulley faces were clean, then the new timing belt was installed. We didn’t go to extraordinary steps to clean everything, nor was the water pump replaced.

We had thought that “line up the timing marks” was going to be an arduous process of HERE, HOLD MY EVERYTHING WHILE I PLUG IT IN, but rather found that all the engine parts just sort of rolled into place. The cam shaft has 4 big springy detents from valve actuation, one of which was just the correct timing. The balancer shaft naturally rotated from gravity to the right timing.

It’s almost like it was designed this way or something.

After the timing belts were installed, we plugged the (newly replaced) distributor and rotor in, connected the spark plug cables, and tried a test run. This was the make-or-break here – if something was terribly amiss, it would show itself upon cranking. If the engine still didn’t start, I was prepared to keep removing things on the spot.

The video is of the second test run. On the first, we were all taken by surprise as to how quickly and smoothly it started up. I was honestly expecting explosions or jets of flame or something.

The engine idled smoothly and revved up smoothly. I blipped the throttle to about 2500 RPM briefly before we remembered that it had no cooling whatesoever and decided to end the test. Success for now.

After the test run, everything is getting reinstalled and refilled.

Your pretend-mechanic hoodrats of the day are Adam, Dane, and yours truly.

Buttoning up everything and rerouting all the cables. The passenger engine everything compartment hasn’t been this together since I got the thing.

Finally, after about 5 hours of work, Mikuvan is back together again. We finished at around 7PM Saturday, still early enough for the sun to be out!

Naturally, a high-stakes all-hands test drive was in order.

The total mileage of the first ever test run was about three or so. Not very much, but enough for me to observe that everything was in good working order (up to 3rd gear), that nothing was overheating or making weird noises, or for some reason it really wanted to turn left. Hell, I’ve ridden in friends’ cars which were consistently less reliable.

The evening resulted in one discovery: the source of the coolant leak. First, a major leak from a misplaced hose clamp on the radiator from our servicing. But second, a persistent but lower flow leak which left me puzzled as to why I was leaving a bread crumb trail of coolant droplets everywhere. It turns out that someone in the van’s 23 year history had sheared a bolt on the thermometer to radiator hose connection, so the gasket was completely uncompressed and leaking.

Well, I sure fixed that.

mission 1

The conclusion of the test drive was the N52 parking lot:

That evening, I topped off the brake fluid and also refilled the gas (with 93 octane premium for sheer kicks) and cleaned off some of the bird shit stains and tree droppings.

Sunday has been filled with gratuitous driving (to places I would normally scooter to or even walk and stuff… amazing, right? It’s the weekend, I can park anywhere!) to double check and recheck reliability in starting and fluid leakage. At this point, I haven’t stalled out once, nor had any more issues with dripping fluids with the exception of some small oil dots that appear after a long period of parking. This tells me that there’s probably a very small but consistent oil leak somewhere. I’d like to get this thing on a lift, still, to fully clean the engine and transmission so I can watch oil leaks form.

Other things I have noticed include a pretty rumbly ride, which could indicate bad bearings. At 151,000+ miles, it’s about time for them to let go. However, during the time on jackstands, I did not notice any wobble or looseness in the front at all. It could just be a natural noise from sitting right over the front suspension.

I have yet to take Mikuvan on any highway cruising to obtain true steady state operation; this is on deck for this coming week. At this point, it only has a pile of minor issues to redress:

• The body panel rust holes on the underside, and the bumper
• The swivelly chairs can’t lock in place – the mechanism is obviously broken on both of them.
• The broken coolant gasket bolt can be resolved by buying a new thermometer unit
• Rims
• Subs

This week, my intention is to maybe take it to a detailing shop to clean the rest of the superficial imperfections out (stuff I can’t attack with a towel and kitchen counter cleaner) and to actually register it. I’m already having immense amounts of fun trolling drivers of more conventional modern cars with its Zeerust-future look and 27 foot turn circle. My ultimate fear is not that I have to learn to handle its peculiarities, but that I’ll forget that everyone else has wheels in front of them. I don’t have front wheels, just middle ones.

Next, I tweaked and diddled enough things to get Mikuvan driving – tenuously, and only for a little while.

We… err, muscled that one back home.

This video was taken before the arrival of my new mass air flow sensor. The engine was easy to keep running when cold, but difficult otherwise after it warmed up, to the point where it would stall quickly if I let the throttle pedal go. The reason for this was yet unknown to me, but a few friends thought it might have something to do with the engine temperature sensor or intake air temp sensor, neither of which I’ve inspected with a voltmeter.  The missing MAF couldn’t have helped either.

But it showed that it could move under its own power! There was hope. I didn’t get up to a speed to shift into second, however, so the transmission remains untested.

After that, still waiting on the MAF replacement, I decided to give the underbody a much more thorough car syphilis rust inspection.

The matching rust holes in the front step got much bigger with some scab picking. Oh boy.

I chiseled each rust patch to the point where the metal became ductile, so some of these holes were growing distressingly large. But these are the full extents picture.

The left side which has seemingly met another vehicle in a somewhat amicable fashion has a large through-hole on the bottom. There is a matching set of holes on the right, which are smaller.

The bumper, though, was in horrible shape. Not the frame where the bumper attaches, fortunately, but just the bumper metal. Above is a picture of the right side bumper attachment point, and this thing was so bad that it was crunchy when I stepped on the rear tailgate. Clearly no longer structural. Replacements for the bumper stamping seem to average $600+, so I might start asking on derpy van owner forums for cars being parted out soon. Worst case, I’m gonna weld a mockup from something ridiculous like 1/8″ waterjet-cut steel plate later.

The deterioriation of the other side was also significant, but much lesser – the metal was still ductile.

I didn’t check extensively for this when I bought it in PA, so I suppose it’s also my fault. I can’t help but think Mikuvan is a little “lemon flavored”. However, given the talks I had with the seller, I ‘m not sure if he knew of the extent of the rust either.

What I can take solace in is that the trouble spots are on the body sheet metal (patchable) and on a “consumable” item, the bumper. They must make the bumper from a lower quality steel on purpose – the frame around it is in fine shape. There is basically no frame rust, which is the important part.

I don’t intend on addressing these body problems yet. It would be nice to get it running before making it pretty – the summer months also have no threat of wet road salt, so if anything, this is a great season to find this out.

The day after, my new MAF arrives. It’s a pull from a ’91 Eclipse.

The MAF unit was the same, but the “can” it came in was much smaller. So, some screwdriver work later and I had the MAF unit swapped into my intake canister. I also got a new air filter during this time, on the left.

After replacing the MAF and resetting the ECU, I managed to get the engine going again enough for a new error code to appear (if the MAF was fixed or I bought a lemon-flavored unit). The ECU read “all clear” this time, but the problems were still present. Inconsistent starting, and this weird cycling behavior:

As I understood it, this might have been the ECU trying different fuel-air mixtures for starting, none of which were quite right. I’m not sure of the actual cause, since I’ve literally never heard an engine make this kind of sound.

One issue I had not yet resolved was checking fuel pressure or changing the fuel filter. I got a Harbor Freight fuel pressure meter, but it clearly required me to cut the fuel line and splice it in to use, something I was not keen on doing yet.

I could definitely try the filter in case it was clogged through:

Cue 2 hours of gentle hammering later, and the “original” filter is out. My goodness, it must have been actually original. The thing was almost rusted through, and when I took it out and shook it over the oil drain pan, rust colored pasty chunks fell out of it.

The replacement filter was a few ounces lighter, and I can’t imagine it being a newer or better design, so I’m gonna say there was a ton of shit inside the old filter.

Remounting the new filter was a relatively painless process. It was in an incredibly awkward location, but at least it was accessible directly from under the vehicle, without dropping anything else, and with only one universal joint ratchet involved!

With the filter hopefully no longer depressing fuel pressure, I tried cranking the engine again. It still cycled as before. This time, I basically couldn’t get it to fire any more, or for it to “catch on” and start idling.

At this point, I decided to move onto the last “0.5″ point of the 3.5 things that constitute spark, fuel, compression, and spark timing: the timing. The thing to do was to remove the timing belt cover, crank over the engine manually to the point where the camshaft pulley lines up with its timing mark, then check the position of the distributor rotor. The rotor should be pointing basically at the #1 spark plug.

So with some trepidation, I removed the distributor cap and and upper timing belt cover.

First, that timing belt is in bad shape. Like worn down to the cords bad. This indicated to me the tensioner roller was probably seized, or the belt was just dragging on something else.

I put a socket on the big camshaft pulley nut and began pulling.

The timing belt jumps several teeth in response and I almost fly out of the driver’s side perch. There was basically zero tension on the belt – see the ‘convexity’ on the right side. I could push this thing in a good inch and a half. I’m amazed the engine ran at all. Perhaps the first few good starts were with the timing belt in a serendipitous position, and something I did caused it to skip teeth thereafter – now, there is no timing the engine can possibly be on which would let it run.

Well, shit just got complicated.

Speaking of the distributor, the points were also in seriously bad, corroded shape. I’m further amazed that it somehow ran now. Luckily, I have a new OEM rotor and cap.

cue Operation: BAD TIMING

I was clearly not going to skip the timing belt back to the right place, and at any rate, it needed to be replaced.

I was at a decision point here. Now, the Official Derpy Van Service Strategy Guide said nothing about what needed to happen before the timing belt was replaced – it just showed every part of the front of the engine in the clear, as if I could access it or something. I basically accepted this was an implicit “Drop engine”. At the very beginning, I said that if I had to drop anything to solve a problem, everything was coming out and I was going electric right away.

Before I did anything else, I decided to seek professional advice – by which I mean ask the Canadian Mitsubishi Delica forum. After getting some reassurance that I would only have to remove the radiator to do this, it became a more palatable task.

I basically declared #YOLO #SWAG: If the operation was completed successfully, then hurray. If not, or I badly fucked over the engine doing so, then more things will just be removed until I am left with a glider frame.

With this in mind, I ordered a new timing belt and tensioner kit:

I got the part from Rock Auto, which seems to be the McMaster-Carr of random car parts. It was even the kit recommended by the forum!

Time to remove more things to get the radiator out. I busted out the masking tape to label wires and tape fasteners to their respective holes so I didn’t end up with like 30 extra bolts after all was said and done.

Hang on a sec – you mean the transmission is also connected to this radiator?

Fuck integrated systems, man. I had to drain the transmission first. Luckily, I disposed of the 20 tankerloads of black used oil last weekend at an Advance Auto Parts locally, so my filth container was available for the task.

The manual indicated that if the transmission fluid smelled burnt, it was a bad sign. Well, what if it smelled both burnt and rancid? I couldn’t describe the smell as anything other than a very sketchy Chinese restaurant. DEXRON-II tranny fluid apparently contains jojoba oil, a natural oil. (Here was when I learned that transmission fluid at some point was made of whale oil.)  Actually, given the history of neglect of this vehicle, it might as well have had used McDonalds frying oil added to the transmission.

(I also totally did not intend to capture the single droplet of transmission fluid in midair, but that’s pretty awesome.)

Also, speaking of automatic transmissions, what is this shit? How can anyone have thought this was a good idea?!

Fuck this noise so incredibly hard. my only previous car and every car i have driven was automatic.

The bleedout of weirdly neon fluids continues with the radiator. This thing has clearly been corroding internally for a while, as the first few seconds of coolant was a bit brown. It cleared up, however.

At the same Advance Auto Parts I made the oil drop at, I learned that coolant could not be collected. Apparently it has to go (in MA) straight to the local public works department or hazardous waste collection site for disposal. That, or through some unscrupulous egging by friends, poured into the toilet so it goes through the wastewater system (as opposed to a storm drain, which around here goes straight to the Charles River, which is itself bad symbolism).

As I learned, the reason is because used oil can be recycled readily, whereas coolant (ethylene glycol) must be disposed of.

Maybe I’ll just polymerize it into polyethylene-glycol and then have a year’s worth of very smooth bowel movements.

After the radiator drain and transmission bleed, I decided to hold off on removing anything else until I have some  backup. Steps from hereon require working under the vehicle while on jackstands, something I am not comfortable with on my own – crawling around under this thing while supported by 4 little spindly steel triangles sound incredi-sketch.

Operation: BAD TIMING is scheduled to occur on Saturday. Here goes nothing in particular! Any peanut gallery advice before I dive in?

I was definitely part of the latter crowd. It was difficult for a professor to actually squeeze out of me a competent lab notebook of any sort.

To encourage more diversity and accessibility in design documentation, this semester I encouraged people to write about their builds on their personal websites or blogs. Now, the Department™ still requires the paper notebook as part of the grade. But, for the last milestone, a reflection and summary type writeup, I decided to break from that and give the students some flexibility. You now had the option of submitting the final MS as a site entry or blog post.

Here’s who took me up on the offer, and those who’ve had a running log of everything they’ve been doing too!

Nick

Stephanie

Nelson

Carolyn

Molly

The crowd this year ranged from those who had some experience with the “design” part of EV Design from taking Mechanical Engineering’s introductory freshman course, to those who had experience building larger mechanical systems through FIRST, or who were basically pros already. I was afraid a little of going 2-person teams this year, since inevitably you might come to hate your partner, but the group was small enough, and enough of the class knew each other already, to avoid unwanted team dynamics for the most part.

Designwise, it’s particularly worth pointing out that nobody built a “normal” go-kart. By that, I mean 4 wheels, single rear axle, sit-down. There were many “tadpole trike” style designs which tried to save cost and complexity by using one rear wheel, so as to afford a better powertrain. That’s as ‘normal’ as the crowd got, and it only became more exciting from there. “Bobcat” style lever steering was infectious – of the three designs which steered with “rudders” as we called them, nobody used tank steering, but the linkages were hooked up to the front wheels to pivot them. And on top of all that, there were not one but two designs which placed the driver face first, lying down. That’s what I get for setting very few rules about the actual design, I suppose.

This post is just going to be a competition recap – after the previous update, there was only wiring and drive testing involved, most of which was in the parking lot so was not particularly exciting to watch. Skip to the bottom for the highlights video!

The most pressing task on my end in the last few weeks was preparing the defense strategy for the garage events. Last year, in response to safety office concerns about people nosing head first into concrete walls (a real and legitimate problem this year!), we set up those big orange fishing nets construction site debris barriers strung up on steel cables. While they could have been okay for scooters and other situations where the rider is roughly net height, the go-karts would all be too low for them to work (in the worst case they’d just strangle you on the way out). The nets were also a pain to set up, and once they were un-deployed, we really had no hope of ever saving them again since the steel cables became tangled up.

Last year, I bought a few bricks of blow-in natural fiber insulation (made of shredded cloth and paper, more or less) to pad the structural columns of the garage. My goal this year was to convince the safety office that a row of these (soft, fluffy) bricks was all you needed for go-karts. After all, everyone will hit things more or less at the same level this year, and the combined mass of the bricks plus their deformability will do a better job than a slingshot cable-hung net. Fortunately, convincing them was not particularly an issue – I basically got back the professional version of “lol k”.

So up they went. Myself and 3 students, the evening before the competition, set up the garage’s narrow wall end with a discontiguous wall of fluffy bricks. Notice that there’s “panel gaps’ on the order of 5+ feet. It would bad if you approached right at it, but on most floors, people came into this turn very wide, so it was highly unlikely for someone to slip through the gap. Plus, you’d have to be completely ballistic and motionless to not at least try to aim for the soft parts. This solution is much more scalable – setup and teardown took around 30 minutes each.

Besides the narrow end-turn region, a few of them were scattered around the columns as usual. 78 little fluff bricks were used in total, and after seeing how little of the average 14 foot box truck they filled, I’m completely fine with filling in the big gaps on the next runaround.

The morning of the competition, the same box truck was used to haul everyone’s karts over to the contest site.

Well, those who arrived by 9am anyway. The stragglers were forced to push their karts over.

First event of the day was the drag race. As the event organizer, I couldn’t get many pictures of the setup myself, and we were short-staffed enough in the morning that nobody else really got any either. At least there was video.

The two top placers in the drag race were a hundredth of a second apart yet represented opposite ends of the traditional EV design spectrum. One was huge, had giant balloon tires, and two massive DC motors. The other was small, lightweight, and had a single brushless motor.

After the drag races were done, we broke for lunch and then began the garage hoonage that is now a hallmark of silly vehicle activity at MIT. This is a Dramatic Photograph of the drivers’ meeting, basically me telling everyone where the start and finish are, in a protracted fashion.

Recall what the “garage challenge” was. Your total time climbing the four levels *and* your energy consumed (in watt-hours) is recorded. The product of the two is your score (with units Joule*seconds, though we used Wh*s for shorthand). Here’s what the results from 2012 looked like:

It’s basically a measure of how efficient you are at doing things. This actually has a mathematical basis in the concept of action. The closer you are to the original (0,0) of the graph, the less energy you used AND the faster you did it. So, there are actually myriad ways to score in something seemingly as simple as driving in a long upward spiral (for the same driver – the score is, of course, affected strongly by mass). You could run wide open all the time and get the best time, but you might use a ton of battery energy in the process – and hence could lose to someone more middle-of-the-road and who took it easy.

Here’s some photos from the garage, since by this time, more people were awake and ran over to take pictures:

“Supermankart” (which I whimshically termed “Suicidekart #2″) on the last leg of the climb, with the finish line around the corner.

The only thing to resemble a normal 4-wheel kart if it were not for its “reverse lawn tractor” steering patched on during the middle of term, the affectionately named “Beschleunigen Warenkorb” – as far as I understand it means “accelerating shopping basket“.

Suicidekart #1 “RoachKart”, so called because it’s extremely flat and quick, and on top of that seems to like going in random unintended directions.

“MiloKart”, named after a dorm cat with allegedly a very disproportionate rear end. The wheel is an 18″ lawn tractor wheel.

Zoran, the Norse God of Marshmellow Cream Puffs speed, and not to be confused with Zorak. The two builders of this machine blog more often than I do.

Bull Kart, nicknamed “lugekart” during the semester, so called because of its two long vertical footrest bars. It was basically a motorized street luge built using longboard components. Here, one of the drivers pulls a tighter-than-usual turn.

“Derpscooter”, one of the two contenders for first place along with RoachKart. The power system of this contraption was a C-8085-180 “short melon” motor with a 150A Kelly controller. It’s the first usage of a melon-class motor with a controller that can actually feed it well – often, people try to use these large motors with small controllers that inevitably detonate or are severely underpowered. Derpscooter edged out Roachkart in both competitions by single significant figures to take the overall win.

Camera car service was provided by shewu operating the DPRC…and an iPhone 5.

What’s left to do after the competition is over? Dispense with the clean, orderly arrangement of loading up and just start piling. This beautiful traditional go-kart-and-fluff arrangement was promptly shat out unceremoniously into our shop building’s loading zone.

This year, unfortunately, due to “No, I do not want to deal with the paperwork of you driving under a bus” reasons, students will not be allowed to keep their vehicles. So the last hurrah for everyone was at the 2.007 main competition:

During the intermission between the elimination and playoff rounds, there was a parade in front of everyone.

I was presented with this set of “nonfuzzy dice”, laser etched with everyone’s creation logos or CAD images, in walnut wood. My students had all heard of mikuvan by now, so I guess some of them banded up to create something for it. These nonfuzzy dice will be mounted proudly in wherever you’re supposed to hang dice that aren’t fuzzy in a car.

And now for the tl;dr: the highlights video from this year!

And here’s the compiled graph of results from this year:

Compared to some historical vehicles:

But wait! There’s more.

the summer session

I’ve been specially requested by the SUTD Collaboration and Mechanical Engineering to run a summer session of this class!  28 Singaporean sophomores and juniors will be coming over to MIT this summer, and they needed something to do. Well, do I have the adventure in stock for them…

The plan for this crew is *eight* teams of three and two additional teams of two for those who are more skilled. The students are less mechanically inclined than my class this semester, and they will have to learn to deal with our curious units system. So, there will be some changes to the course material. The class is only 8 weeks instead of 13, so I’ll have to plan which “milestones” to condense accordingly. And, more materials will be provided, because the impact of having to wait a whole week for a part will be unacceptably great in this timeframe. People will still have the ability to specify their own parts if they want, but otherwise, I’ll have a giant bin of things to pick from.

Stay tuned for the third great race-off at the end of summer.

It’s hard to believe that I only went on the Great Van Escapade a week and some ago. Between then and now, I’ve done many hours of disassembly, testing, and debugging. I think I’ve finally rooted out the problem, but am waiting on some more advice and recommendations before proceeding. Why am I even buggering with fixing the ICE engine, with all its attendant pre-OBD-but-post-CARB Mitsubishi-only oddities, when I’m just going to unbolt it all and drop in an electric power system? Not quite sure, but some of it has to do with curiosity in figuring out exactly how much of a complexity nightmare ICE vehicles are, and others because I have 20 more days of temp plates left. Getting in some driving feel would be immensely helpful too.

Mikuvan lives in the enclosed underground parking garage under my apartment block, next to a Honda CR-V, a Volkswagen Golf, a Prius, and (among other cars) a 1963 Mercury Comet. Good, I’m not the only project car sitting in a pile of its own parts. Looking down the row of parked cars is amusing – all you see is hoods and headlights…and then there’s this.

At least it’s not on-street or outside. But the downsides of this arrangement include the total lack of AC outlet power nearby, poor lighting, and a lack of Wifi or cell reception. The nearest outlet is 75 feet away, necessitating some extension cord creativity. I have a 500W halogen work light to relieve the lighting issue, but it is still only one source. The latter issue means I often neglected to bring cameras or camera-enabled things with me into wrenching sessions. Hence, even though there were plenty of cool photo ops, this post will sadly be mostly text.

Hey, so is my air filter supposed to be furry?

The story of digging in around in the drivers seat engine bay is centered around consulting with people who know a thing or two about what cars are, then vaguely following their suggestions but ultimately falling back to the Official Strategy Guide / Shop Manual to figure out through its well-drawn but extremely narrow view diagrams where the parts in questions actually were.

It’s often said that you need 3.5 things to get an engine to work. Spark, fuel, compression, and when-does-the-spark-fire (i.e. timing the spark, the 0.5 part). I basically began by checking the ones that were easy: spark and compression. To check the timing properly would have involved exposing the timing pulleys, which, as far as I could tell necessitated removing the radiator and cooling fan shroud, then also removing the distributor cap which was more accessible. I did not feel like attempting this in the dark with limited tools. In Pennsylvania, we already verified compression, so I started by checking the spark plug lines.

I bought 2 of these in-line plug checker lights from Harbor Freight (not sure why I just didn’t go ahead and get 4). The firing order of the engine is 1 – 3 – 4 – 2, so I started by putting the lights on 1 and 3 to verify the order, then 3 and 4, and so on. Basically to make sure that 1) there was spark even if it may not be the correct timing, and that 2) the  cables weren’t switched around or something.

The sparking order checked out fine, so I began reading up on fuel injector testing and cleaning. My suspicion at this point moved to the injectors, since they were really the only element left. I highly doubted it was a timing issue in that somehow the timing belt (which is in great condition as far as I can see – it must have been replaced fairly recently) skipped 1 tooth or the distributor cap rotated enough such that I got completely inconclusive cranking – even a late spark would give me some kind of ‘puff’ and an early spark would cause premature detonation and horrible noises.

But I couldn’t help but think that all 4 injectors failing or clogging at once was extremely unlikely. In my experiences with watching friends tell stories of problem cars and from a few trouble vehicles my family has owned, engines don’t just suddenly stop working unless either something

1. catastophically failed on the mechanical side, which I would certainly know by now, or
2. a single electrical point of failure such as a sensor is preventing the ECU from running the engine properly

My money was moving towards some stupid sensor failure. For instance, if the crankshaft position sensor, used for fuel injection timing and electronic spark timing (the ECU fires the ignition coil when it feels like) is out, then the ECU won’t know when to do either of those things. If the throttle position sensor, which is potentiometer based, was broken or worn, it could be reporting a completely nonsensical value, though this seemed less likely since you’re never supposed to step on the throttle while starting, unless you know exactly why you have to. There’s other sensors involved too, like the mass air flow sensor which the ECU uses to determine how much fuel is metered into the cylinder.

With all of these things having to work in synchrony, I’m amazed cars function at all.

Here’s the scene of the crime, lit up by the aforementioned 500 watt halogen light. It kept the area reasonably warm, as the rest of the garage is unheated and basically settles to its own temperature by thermal inertia alone (surely it will get unbearably hot during the summer).  At this point, to access the fuel injectors and high pressure fuel rail, I have the passenger seat slung up, the driver seat removed, and the underframe of the driver seat also detached but just shuffled out of the way a bit since it has the parking brake lever, fuel door lever, seat belt anchor, and a host of other stuff on it I don’t feel like dropping into the engine.

Here’s the whole mess from the other side. The shop manual has been my reading material of choice for the past week. It’s extremely informative, but at the same time I can tell it was written by mechanics for other mechanics. I assume that the unlabeled detail shots require some background in wrenching to understand where to insert the thingimadoodle and how many degrees to turn the whatchamadoosit. There’s other info missing such as sensor pinouts right after it tells me what voltage this or that sensor should read…

…While the engine is running. How about a little help for the other case here, guys?

Before taking even more things apart to get to the injectors, I decided to see if it could tell me what was wrong.

Okay, now I’m seeing something familiar. My van debugs like a Kelly controller or Hobbyking controller!

It predates OBD (“OBD-1″), so it has multiple means of debugging available. You could buy the $500+ “multi-use tool” which is like a form of proto-OBD scanner, or you can debug with a voltmeter. Not a digital one – an analog one. It puts out little pulses of voltage so you can see the needle move (digital meters do too much time-averaging to see this effect). If I added an LED to the circuit, I literally could have watched it blink. It probably would have said “FREQUENT RESET” or something, knowing the average Kelly controller.

So an analog voltmeter it is. It took me a while of digging in MITERS to even find one of our crufty analog voltmeters, and I ended up having to make hardwire leads for it anyway.

But it worked! The key has to be turned to ON (not start) for a few seconds for the ECU to start putting out pulses. The result is:

Normal State!

Oh, come on.

My guess is that since the vehicle has not been started since my new battery was connected, the ECU doesn’t know what’s good or bad. The engine must run, no matter how crappily, for a while before the ECU can recognize something is out of range or nonresponsive. My mission now was to try and get the thing started no matter what. If the injectors were clogged, then I’d have to unclog them.

One thing I was told to try was to drop carb/throttle body cleaner (i.e. vicious, surely carcinogenic,  and highly volatile solvent cleaner) directly into the fuel rail, mixed in with the gasoline, to try and dissolve anything which might be causing injector blockage on the spot. Basically you cycle the injectors bathed in disgusting solvents and let it sit for a while, then try again. Rinse and repeat. I bought a little can of Seafoam on recommendation from friends, which appears to the most disgusting of the disgusting solvents since it claims to clean everything. Seems legit, right?

The procedure was to disconnect the high pressure fuel line from the rail, get most of the fuel in there out, and replace the rest with Disgusting Solvent #81289. I wicked fuel using a few shop towels, which were promptly lit on fire for my own amusement (this process does not have photos associated), and mixed in Seafoam about 50/50 into the rail. Next, I gave the engine about 10 seconds of crank to get the new mixed drink into the injectors. During this time, the engine sputtered a few times.

Promising.

An hour later, I came back to give the engine another spin. 10 more seconds of excited cranking and sputtering later, it took off.

It was shaking like crazy and white smoke was everywhere (allegedly a sign of the cleaner doing its thing), and the revs were unsteady for the first few seconds of run. It seemed to settle into an idle, though I was both too excited and scared shitless to check the tachometer for functionality. Something was happening.

I was under the impression based on checking the dipstick in Pennsylvania that the engine was very low on oil. It was also running with zero coolant. Fearing causing damage due to lack of lubrication, I shut the engine off after about 20(ish) seconds of running.

it did something

Unfortunately, that was the only run I got out of it that night. I regrouped thoughts for a bit to formulate the plan of attack if it started and ran more than once. On the next shot, there was some more sputtering, but no consistent behavior. I gave the air intake a dose of starting fluid to no avail. By the next few tries, the battery was wearing down too low to crank effectively. I’d have to bring in my charger and top it off before trying again, so I cleaned up for the night.

That was when I noticed that the air flow sensor wasn’t connected at all.  Remember the air filter shot? I opened the air cleaner box to remove and replace it with a fresh one, but neglected to reconnect the airflow sensor.  So, the engine running must have been pure luck – or the cleaner/solvent making for such a volatile mixture that any small amount was sufficient for it to keep turning over. The air flow sensor is a “hot grid” type sensor (looks like this) used for air mass calculations. If “disconnected” also means “off scale low”, it means the ECU would think that there was no airflow. No airflow means no air mass to calculate fuel injection quantity with. And no fuel means no combustion except if you’re basically mainlining Seafoam. My exhaust system is probably really clean right now.

Yesterday evening, I tried re-adding some cleaner to the fuel rail (in lesser quantity) to try and confirm this theory. I got the engine to sputter some times, but no starting and running was observed.  I also noticed that the ECU code had finally changed to:

Air flow sensor.

It was definitely connected. I even abraded the pins a little and recrimped the socket to increase contact pressure just to make sure it had connectivity. I couldn’t tell if the element was damaged (it looked good, even clean) or the entire sensor had just stopped working or what. I cleaned the grid element with some rubbing alcohol and let it dry under the halogen lamp for a while. No obvious changes were noted, nor were any starts effected. Maybe “disconnected” is a totally different signal from “porked”.

A new-used MAF sensor costs about $120 on eBay, so I went ahead and ordered one. Even if it’s not the problem, I now have a debugging chain to follow instead of shooting in the dark.  The airflow sensor being problematic would corroborate my theory that some critical sensor failing is causing the ECU to not control air, fuel, or spark properly. We’ll see how this goes.

With these new developments, I decided to do some staging and preparation. First, I wanted to get the disgusting sludge oil leftovers out of the engine and put in something fresh. On the same Harbor Freight trip earlier in the week, I anticipated needing to do this eventually so I got an oil filter strap wrench and a waste oil container, the kind with the integrated drip pan. I ordered a new oil filter off eBay (the best auto parts store!) last week already.

The oil drain plug and filter were clearly designed to be accessed from an auto lift. I didn’t have this, so luckily the thing has a massive front nose cavity…

The plug and filter aren’t visible in this picture, but they’re right behind the front suspension arms. The radiator to the left is the A/C condenser – it’s the first thing to hit if you drive over a tall curb or something.

I also noticed while I was under there that the transmission oil pan is basically the first thing to hit the ground if I go over an enthusiastic speed bump. I’m not sure how they expected this to navigate the rough streets of the U.S. while loaded with seven U.S. sized adults. Maybe everything was smaller back in 1989…

It was black. ALL BLACK.

Around 5 quarts of entirely black oil poured out of the crankcase. Like, this stuff was basically the color of the filter. So it did have oil after all! “Oil”, anyway. I think we must have read the dipstick wrong in PA, since we swore it had very low oil.

Always a good thing to find in the drip pan – little metal particles. And chunks of sludge.

I let both filter and drain plug ports drip for over an hour (while waiting for the battery to charge) before refilling it with some new 5W-30 from the gas station. I didn’t bust money on premium oil since I figure it wasn’t going to stay in the car for too long anyway.

Oh, also, the oil filter had basically no torque on it. I didn’t even need the strap wrench – just the torque of my hand trying to engage the strap loosened it. No wonder there is a thin sheen of oil all over the underside – it must have just been leaking forever. I made sure to crank it down when I installed the new filter.

The game right now is to wait for the new airflow sensor and see what happens from there. I’ve pledged to give an honest debugging effort to this thing even if I’m not keeping the engine for long, and I’m willing to spend some money on it.  I’ll make sure to take more pictures of everything in the future.

This is also the first post in the new Mikuvan build thread. Oh boy, I’m in deep now…

Okay, strictly speaking, it’s currently a “van shaped object”, since it doesn’t run. So, more accurately, I just bought another potentially never-ending project.

Before I reveal the details of what transpired this past weekend, I’d like to plug one of my MITERS compatriot’s robotic shindig coming up this weekend, Hexacon 2013 at MIT. Organized and hosted by Nancy of Orange Narwhals fame, this event will feature everything that has 6 legs (plus or minus a few) and is robotic (or can pretend to be so). If you’re in the Cambridge or MIT area, come on by. It’s being hosted about 50 feet from my desk nest midden in the International Design Center space.

Hexa-van?

Anyways, before everyone asks the obvious question of “How the hell did you pick this one, of all possible cars on the planet?”, let me explain the backstory a little. Raise your hand if you’ve ever seen these things on the internet:

If you haven’t before, you’re welcome.

Basically what is going on here is a Japanese pokemon “vanning” show. While U.S. van culture appeared to have died out by the time the 1980s rolled around, the movement picked up speed in Japan in the 90s. The digimon vans above are all 90s model Toyota Hiaces, a vehicle not sold in the U.S. for using the driver as a crumple zone. I’m not in tune with the Japanese internet (only some parts of it, and not the automotive bits) enough to know whether or not this still happens, or like most things about Japan that get crossposted to the North American imageboard market, actually stopped 10 years ago and we’re just watching badly dubbed reruns. Whatever the case, even if these kinds of Flamboyantly Gay Decepticon mods have died out, “VIP style” and other less ostentatious mods are still common.

Many of these get pretty ridiculous and they’re often adorned with the images of singers, characters, or the odd politician or two.

Popular features tend to include fake Testarossa style side strakes, side hatches, extended front and rear lips, cowlings and visors, an enormous rear plume, and those weird antenna things sticking out the front that look like curb feelers for rooftops. I’m not even sure you could move 5 feet in that in Boston without being stuck in a pothole.

I was introduced to these things some time in high school while reading then still-embryonic car blogs, and as I tend to do to extraordinary mechanical things, immediately fell in love with them. Sadly, if you are looking for more, I can no longer help you. All of the gallery links I bookmarked in high school have disappeared from the Internet. Short of speaking Japanese yourself, searching for “バニング” on Google Images (it being the katakana syllabic representation of “vanning”) will probably lead to the most returns.

Anyways, the plan for my van is not to completely dress it out. It comes from before the era when CAD programs supported things like fillets and lofts and G3 continuity surfaces. I think it has to retain the somewhat Brutalist, built-on-the-fly aesthetic, maybe like of like melonscooter. As of right now, all of the electrical accessories work but the engine doesn’t start. It cranks, and seems to try really hard, but something is just not going puff. I’m not historically a “car guy”; the only car I’ve driven in the time before nearly-new rentals and shared-used cars was pretty tame and reliable, so I hope to use this to pick up a few skills and learn some new things (some of the gory debugging details are forthcoming). I would like to get it running, even if rudimentary and completely emissions-destroying.

The ultimate plan for it is going full electric.

Yep. I’m doing it. There’s no turning back now.

I’ve always thought that it would be fun to have an electric car, even if they are less practical than a fuel vehicle at the moment. I like EVs. For a long time now, I’ve been sort of halfheartedly wanting to do a conversion, but the price of parts has always been the killer to that ambition. Even for the most basic conversion with lead batteries and DC motors, you probably won’t get away with under $7-8,000 (if you bought all the parts), not including the vehicle, and it will be extremely stripped down. AC and lithium systems will easily cost 5 figures (if you bought all the parts).

Emphasis on if you bought all the parts. I’m lucky to be surrounded by some ne’er-do-well friends who bought out the remains of failed electric car companies or worked at battery companies designing lithium ion battery modules (and abandoned ship before they went full Titanic and now run nuclear reactors). Stationed in the next lab cluster down the hall is an electric vehicle club bored of full size cars and now totally into bicycles and motorcycles, with their attendant spare and unused parts. Downstairs is an auto shop with a 2-post auto lift (and 19″ giga-lathe among other toys). But most importantly, I now have a real parking spot in the basement garage of the apartment complex I currently reside in (and which I pay a fee for it in the rent anyway, so why not?). The alignment of circumstances means #yolo the time is right.

Operation MIKUVAN

This story starts a few weeks ago through a combination of peer pressure and realizing that the stars of electric hoonage were lining up. If you’ve ever had friends offer you narcotics or alcohol, it’s like that except 150kW induction motors, inverters and LiFePO4 battery modules. Don’t make my mistakes, kids.

My derpy Japanese van fandom took a back seat (…) to other interests in the intervening years between high school and now, but I always thought about it from time to time. Living in the extremely dense Cambridge-Boston area means I never need a car (and if I do, all sorts of rental car agencies abound). Hence, any car I buy would have to be worth driving to justify the expense of parking, insurance, fuel, etc. Did I say fuel? My grad student income at the time was also (of course) insufficient to take on any kind of project like this. These days, being a shop instructor pays better – not the most glorious job, of course, given the mixed income priorities of our current economy, but I like the environment and interacting with the students.

So recently, every once in a while, I’d breeze the local Craigslists to see if there were any easy catches nearby. I always passed them up since I couldn’t ever justify throwing down a thousand plus dollars. The last cab-over style vans imported into the U.S. were sold in 1989 and 1990, so anything I could get from the Northeast would probably be more rust than van. I also checked southern cars around Atlanta, ones I could potentially get and then immediately stuff in my mom’s garage in Atlanta. The most common models of these in the U.S. are the Toyota “Van” and the Mitsubishi “Van” and the Nissan “Van” (in that order). Such naming creativity. The Toyotas dominate by sheer numbers, and there is even a fan club dedicated to them.

Three weeks ago, I came upon this listing in the Harrisburg area Craigslist.

Hmm. I’m not even sure what that is, but it looks a little dinged up. The ad specifically said it wasn’t running. It was $1,000, but I figured I could leverage that fact to talk the seller down a bit. This was clearly where all the Equals Zero Designs revenue was gonna go (OH GOD EVERYONE, BUY MORE RAGEBRIDGES PLEASE)

A few back and forths with the seller about what the state the vehicle actually was in, and I became more confident that it could be a worthwhile effort.  A history report on the vehicle checked out clean, and further pictures from the seller showed that the body and interior were in good condition, save for some rust spots on the outer body panels typical of a 20+ year old northern car. I trusted the seller when he said there was basically no frame rust, and that it has just stopped running about a month ago. At the time, it sounded like an easy fix.

Fast forward until Saturday morning, Harrisburg, Pennsylvania.

Team Mikuvan comprised myself, Dane (of Transistor-Man), Adam (of Flux Wonderland), and Cynthia (of Cynaesthetics). The plan was simple: Rent a local U-haul truck and trailer, and drop the thing at the nearest auto parts outlet and try to get it running in the parking lot, then (very carefully) driving it back to Boston. I would mention the best laid plans of mice and men, but these plans, best laid they were not.

This was actually my first time driving a trailer, especially a trailer I couldn’t see. I had to get used to getting into the next lane over to make a turn, and my simulated trucker skills were tested to the max on occasions.

On location and checking out the goods. I basically declare it “Item As Described”. Indeed, there were two rust holes in the bodywork – near the front wheelwell where it intersects with the boarding step by the front door, which seems like water could just have puddled in that area. Other than that, very minor patches on the body, and virtually none on the frame and underbody. For the price, I’m not going to be extremely picky.

Here’s what it looks like from the front.

Dat 5mph bumper.

And a rear quarter shot. The blacked out OEM paint in the front makes the greenhouse look bigger than it is, and it really imparts an 80s LEGO set spaceship kind of appearance. I approve.

Here’s a look inside. These types of vans have the engine compartment directly over the front axle, in a camel hump. The passenger essentially sits over the engine, and the driver over the battery and coolant bucket. To do most mechanical work, you have to drop the engine or get it on a lift. I kind of see why these things never took off. Plus, the later models tended to catch fire because the Japanese had to design bigger engines into them than was thermally prudent in order to keep up with American demands.

The engine did turn over, but did not fire. It burped once or twice to no avail, which was at least a good sign that it wasn’t seized or something. There was basically no coolant, and very little oil.

Scoping out the rest of the interior and checking out the electrical dongles. The seller let us temporarily install one of his batteries in the bay to make sure the lights, sounds, and spinning hubcaps all worked.

With the deal completed, it was time to attach it to the trailer. Because the engine wouldn’t generate horsepower, we resorted to manpower. I sat in the cab and steered (and pulled the e-brake).

We backed it up about 50 feet from the trailer and gave me a running start…

I was legitimately afraid of becoming a Youtube sensation, but it all worked out in the end. I stopped early the first time, since I forgot that this thing doesn’t have front wheels, it just has middle wheels.

Glory. After the physical loading, the seller and I went to a local tag office to transfer the title and for me to pick up a temporary plate (seeing as how at this point we were still sure that we could get it running in a few hours)

If I thought driving a trailer was fun, then driving a trailer with 3000 more pounds on it was even more fun.

We landed in south Harrisburg near a strip of road where there were a dozen garages and car parts places within 2 miles. During this trip, I learned that there were really only 2 ways to drive a trailer – either you are slow and gently moving, turn signals flashing all the time such that people are eyeing you and staying away…. or FUCK YOU, I’M BIGGER. Both seem to be legitimate.

I’m proud to say I only hopped one curb. Here’s the initial stating and plotting of the attack plan. We were going to just follow the “Engine won’t start” debugging chain in the shop manual I bought on eBay the week before.

Starting the intial teardown of the cab. We wanted to expose as much of the engine as possible, just in case the Thingiemadoobob needed to be removed to access the Widgetizing Sensor.

Trying to locate and figure out where various pipes, hoses, and wires go.

Mike, another friend skilled in automotive misadventures, lent me a timing light for the weekend, and we also had a compression checker. The first thing to check was spark and compression, just to verify the fact that yes, in fact the engine is still engine-like. Despite having the timing light, I don’t think we used it correctly, and ended up checking the sparks manually (taking one out at a time), which may not actually have told us anything about how it worked in-place. All 4 cylinders of the engine were verified good for compression.

I bought a new starting battery from Advance Auto Parts. The battery tray was full of random bits of styrofoam for some reason. Another interesting thing to note is that the coolant tank was missing. The seller claimed it worked fine and that he just needed to periodically top off from the radiator.

…Okay?!

I also bought all new spark plugs. This is a picture of an old one – it’s pretty gross. The seller mentioned the engine did burn oil, and it looks like it has been doing so for a long time.

The afternoon is slowly turning into evening. We’ve moved onto checking the fuel system now – fuel pump, fuel filter, the injector rail, and finally the injectors themselves.

The trailer itself acted as a makeshift auto lift. The van is hollow enough underneath that we could sit up and work instead of lying on our backs. The first order of business was checking the fuel pump for functionality. We jumped 12 volts directly to it and heard it run (and felt it pressurize the fuel line), then verified that the plug going back to the rest of the vehicle was also giving it 12 volts when trying to start.

Two’s company. One person held the alligator clips and the other checked the fuel line pressure.

We did find a pen in the engine, but sadly it was not the cause of the problems.

The rest of the day before it got dark was spent failing to get at the injectors (it would have required significant disassembly of the throttle body, as far as I could tell), and using carb cleaner directly in the rail to try and clean the input side out. We didn’t try replacing the fuel filter or bypassing it. After it got too dark to work, we called it a day and checked into a local hotel.

Here I am quintuple-parking in the lot. I had Dane box me in using the rental car to ensure that nobody else does – I’ve seen someone else get boxed in by other cars, so that’s why I thought of it. It’s now Sunday morning.

With the U-Haul already late a day, we made the decision to get back to Boston before sundown. I rented local, so for the one-way trip back, we had to swap trailers. This involved some amusing e-brake offloading from the trailer, then subsequently reloading onto a new one. The U-Haul guys were grumpy at first that we were demanding a one-way rental at the end of the month on a walk-in reservation, but they came back out with towing chains and ratchet straps shortly thereafter and helped with loading up.

The same “Come At Me, Bro” run-up technique was used to load the van for the return trip.

All loaded up and ready. We broke convoy since there were two of us who were van bums and two with real jobs they needed to get back in town soon for. The drive back was like any, except slower and with a lot more staring at lane changes.

And tolls. My god, the tolls. I’m fairly certain they were counting axles on the van, too. The Tappan Zee bridge (my usual northeast gateway) suddenly became $25, from $5 for a single car.

Adam rode in the van all the way back.

No, not really, though we did want to troll drive-through fast food places by placing 2 orders from the same vehicle train.

The unloading procedure was only slightly shady. Basically, the entrance to the garage is on a long down-sloped road. The trailer was parked upstream, and I rolled down, whipped a quick turn to point into the garage, then was pushed over the curb cut and coasted most of the way to the spot. A final shove exploited the van’s 25-ish foot turn circle and I nosed into my spot.

Now, getting this thing back out is going to be incredibly adventurous.

My time in the next few days will be spent preparing for the Second Great Go-Kart Race, the finale of 2.00gokart. I want to get in a good debugging day on this thing in the coming week, at least to pinpoint what’s wrong. I really do want to get it running, but because of the overlying goal of going full electrons, I’m not going to spend a great deal of effort trying to get the gas engine going again. If the fix requires an engine drop, it’s staying dropped and going on eBay or Craigslist, and I am going all-in.

The current state of the engine:

• Fuel pump: Functional
• Fuel filter: Unknown, but feels fine
• Fuel injectors: Unknown
• Spark: All 4 plugs verified independently, not in-place
• Compression: Yes
• Timing: Unverified
• Vacuum: Why the hell do cars have vacuum systems?
• Crank sensor: Unverified
• Fuel pressure sensor: Unverified

Most of the people I’ve talked to who know a thing or two seem to point to the injectors, but I’m really wondering if all 4 of them can clog or break at once. It seems like a small, single point of failure which is not mechanical is stopping the engine from working.

I’ve considered patching together a quick slow drive system that bolts into the rear bumper or underframe which will at least help with garage extraction and act as a push-assist. Nothing major, just big wheelchair motors or a spare ETEK motor or two and welded steel. The trip from garage to auto lift is basically 1 mile, but on city streets. I suspect much night-hoofing will be done and orange glowy triangles and emergency blinkers will be involved. I don’t anticipate starting the conversion until summer at the earliest, and am basically anticipating it being a multi-year project much like LOLrioKart, except much bigger and more complicated! Shenanigans shall commence.

So, why is  it called MIKUVAN?

No particular reason.

Just one of my usual random project nicknames.

I’ll probably end up naming it Derpyvan or something. However, this is definitely one form of decoration I would unironically drive.

Some of the students have been industrious and scheduled their checkoffs and inspections early. Here’s a preview of the action that will unfold in a much larger space next week:

Because conventional controls and riding postures are for wussies, apparently. I’m both amused and somewhat terrified at the prospect of there being three (out of eight) karts in which you ride head first. As it was my stated mission to not interfere much with the design and construction of the karts to let students experience as much of the design process, I might have to start padding BurnoutChibi and run interception for wayward karts.

Speaking of which…

Here’s a picture of the aftermath of BurnoutChibi’s motor detonation. As I would later find out, the sparks seen in the video were not the magnets grinding on the can, but rather them cutting up the phase wires.

Here’s a better picture of the ownage. The red wire, in particular, was cut almost all the way through. The annoying thing about this is that the wires were so close to the stator. If they were further out, patching would be a simpler job. I’d have to loosen the epoxy holding the wire stubs in place and also trim the heat shrink selectively.

While I await better motors, i decided to try and repair these. First step was to pop them open. There is a front retaining ring that comes out, then 2 set screws loosen up to free the shaft from the rotor. Then it’s a matter of pushing the shaft out to the right in the picture – this step was done on an arbor press.

Ouch. In total, five magnets broke loose. I figure this must have been a chain reaction where one magnet ditched first, and the resultant imbalance caused can deformations which broke the rest loose.

This is why I recommend motors that have “rotor bearings” or “skirt bearings” to everyone who asks me about them for vehicle apps. Even though it adds a little drag, the distal end of the can is properly supported on its own bearing. The only exception is if the motor is very short, like a more “pancake” style design.

I mixed up a generous dose of long-cure epoxy with glass microsphere (microballoon) filler, to slightly under nutella-like consistency. The offending magnets were pried out, the mating surfaces cleaned, then this epoxy smeared into the new joint. I replaced the magnets and used as much of the remaining epoxy as possible to completely fill in the gaps between them.

Evidently, I didn’t add enough microballoons, as the mixture did sag a little. To keep the cure symmetric, I actually chucked this thing into Tinylathe and ran it on a very low speed for several hours.

After the mixture was firm (but not cured), I set it on a radiator to cure with heat. Luckily for me, the radiators in the building were still on; they were switched off successively as recently as 2 days ago!

I didn’t get a good picture of the wiring repair before, but it basically involved exactly what I described before – carefully scraping away the heat shrink tubing to expose as much wire as possible. The wire was actually all magnet wire, so it would have been difficult to solder. To combat this, I “frayed” each lead as much as possible to expose the maximum amount of magnet wire surface area. Then I cranked the 80W soldering iron up all the way to 850 fahrenheit and literally burned away the enamel by embedding the frayed ends in a big ball of solder for heat transfer.

I think I managed to get back 75% of the red lead. The rest were patched similarly, but did not need as drastic soldering measures.

After the real epoxy fully cured, I reassembled the motor and crammed it back into the left side transmission.

I have yet to ditch a single magnet. Though I figure it’s only a matter of time before the right side lets go…

And with that, BurnoutChibi is ready to lasso its rogue… brethren? Bastard children? Offspring conceived via assistive reproduction technologies? Something. The only thing it does not do very well, sadly, is burnouts! Because the rider weight is basically square in the frame, and is up so high, it really just like to drag the front wheels along even if I’m holding the brakes. The same reason contributes to its severe power understeer (and associated lift-off oversteer!) behavior. Oh well…

As previously discussed, BurnoutChibi is a refit of the derelict Chibikart1 frame into something a little more hair-raising, as if Chibikart 1 wasn’t bad enough already. Since the last update where I had just finished reconnecting the steering, I’ve finished mounting the braking system, the transmission shifter cables and linkages, and also completed electrical hookup. At the behest of some of my students, I completed it in time for CPW last weekend, though the aforementioned motor problem meant it was not out scaring parents and wide-eyed potential freshmen.

Here’s the story in the pictorial form.

I began with a little aside in order to solve the problem of how to mount the two “Sand Castle” controllers. They have no mounting flanges and both sides are made of heat sinks, so just gluing it to a plate would make for some pretty poor thermal design. I decided to come up with a “cradle” that held the two controllers right under a fan for some forced convection  cooling. The fan I selected was out of my plentiful stock of 80mm LED case fans.

This design was an exercise in designing a snap fit for 3d printing. While I could have made the base a little wider and added some through-holes to hold the two halves together, I decided to get creative and dovetail each corner post together. The angle is extremely steep – about 85 degrees – so the whole assembly could be pulled out with force, but otherwise snaps into place cleanly.

…and it’s printed out of PLA.

Yeah, so what if it’s going to melt at about 60 celsius? It’ll just smell like delicious waffles while the ESCs burn.

I decided to try the “translucent light blue” PLA which is sold commonly, and I must say it’s my favorite PLA color so far. It’s not the vaguely jaundiced-rainwater color of natural PLA, and I also don’t like solid color PLA. A tinge of blue helps, but is not overwhelming and makes me think it’s some real plastic.

Putting together some of the electrical deck and testing the fit of the ESCs. Result: pretty perfect!

I set aside the e-deck for a while to return to the transmission and drivetrain.

First order of business is to attach the sprockets to the wheels. This basically entailed making four standoffs which acted as the lug nuts (M6 thread) on one side, and regular 1/4″-20 on the other side. The standoffs hold the sprockets a set distance from the wheel so the chain clears the tires, and also holds them concentric.

Or so I hoped.

There is practically nothing concentric or wobble-free about these shitty caster wheels. I had picked them up since they’re $10 each, but I swear not even Harbor Freight wheels are this bad. While the sprocket seemed to have minimal runout (radial misalignment), the wobble from the poorly stamped wheel rims was incredible.

I literally had to take a dial indicator to the sprocket and hammer on the wheel rims to bend them around. I got most of the axial wobble out of the sprocket this way, but this meant it all ended up in the wheels themselves, which now are a bit “googly-eyed” as a result. It will look hilarious when running.

With all wheels mounted, the frame could finally support weight. It’s definitely lost the Chibikart look a little since it’s so far off the ground (in comparison…). I have an incredible 2.5″ of ground clearance now.

The brake pedal hookup was the exact same as for DPRC. This pedal design doesn’t have a spring return on the pedal side since it is handled by the built-in spring elements in the brakes themselves.

Which, as it turned out, weren’t quite strong enough, so the pedal felt quite mushy and also did not return all the way. I added a long compression spring on each side between the cable stops and the brake lever, and this made the pedal feel much more positive. The brake cables sit in barrel adjusters so the balance could be finely tuned.

Shifting to the back again, I’ve appended the Vex sprockets to the Vex transmission’s VHex output shafts. The Vex sprockets didn’t come with any set screws or other means of axial retention, so for a quick fix, I drilled and threaded three #10-32 screws 120 degrees apart. The three set screws will offer way more retaining power than just one. I decided to forego any other spacers and shaft end-tap screws for now.

Here’s a view of the shifter linkage. The mechanism is a spring-balanced cable setup where I provide the pull to shift into 2nd gear, and the spring pushes the shifter back into first.

This was simple enough, but I chose springs which were way too strong initially. I figured “10 pounds of force” at max deflection was enough, but that translated through the cable into the shift lever, times two, meant it was just too hard to throw!

I went to a hardware store and bought several sizes of springs in roughly the same length that were much ‘softer’. The replacement spring is about half the spring rate, and was also too long in that it could not compress enough. The solution to that was to really quickly dremel a few loops off the spring, just  like a good ricer. The shifter now has a positive click as the ball detents lock into place.

Once that affair was taken care of, I routed the chain and moved the gearbox up to tension it (the “goalposts” having slotted mounting holes for this reason). To lock the gearbox in place, I simply tightened the…

… Oh, I can’t reach those bottom socket screws.

Must have bought those hex headed screws for a reason! I was wondering briefly where they were supposed to go on this thing. With the hex heads accessible with a regular wrench, now I could actually tighten the drive up.

With both transmissions hooked up, I spent some time getting pushed around synchronizing the cables. I put another set of barrel adjusters on the shifter cables so they could be adjusted as needed.

What I (not surprisingly) discovered during this push testing is that the brake shimmy is pretty severe. This is caused by combination of factors, two of which include my “kinematically suboptimal” rotor retention method (two screws across a diameter) as well as the complete non-concentricity of the wheels. To reduce the severity of the effect, I had to dial the cables to different tensions. The braking is still effective, but it definitely feels like it’s trying to jerk all over the place.

Ultimately, I’m likely to ditch these drums and go to a disk brake setup with its own guide bearing on the front spindles to maintain concentricity. But for now…

…back to the electronics deck. Here’s the wiring mostly in place with batteries mounted. The batteries are my old 5Ah, 10S sticks. Two of them.

The batteries are secured by Velcro ties and sandwiched between two rigid plastic panels (the baseplate on one side, a 1/4″ thick polycarbonate strip on the other). A 1/8″ silicone rubber pad sits below each battery for shock absorption and more impact protection. Combined, this ought to ensure the batteries don’t move anywhere.

The ESC power leads directly into a 150A fuse junction, and ground has its own big brass distribution block also. Overall, this is the beefiest power system I’ve built since probably LOLrioKart.

At the point, the frame was flipped over for installation of the power electronics deck. The rest of the wiring, including connections to the motors and to the main switch, happened in-place after the installation.

The long run to the power switch is doubled-up 12 gauge wire in each direction.

The only other power side wiring was to make one motor extension cable. With main power wiring completed, I quickly hooked up a HV BEC to provide 5V and a servo tester to convert the foot pedal’s analog 1 to 4 volt output to servo pulses. These two components were heat shrunk and sealed, then attached with Velcro to the top of one of the battery pack plates. The signal electronics for this thing are extremely basic – no fancy signal processing is occurring.  One thing that could happen with this system in the future is converting to electronic shifting, such as with solenoids, upon which I think a system which cuts throttle before the shift and slowly brings it back in would be helpful.

After confirming the functionality of the ESCs and calibrating the controllers, the whole rig is put together.

Here is BurnoutChibi posed next to DPRC! The wheelbases for both vehicles are the same, but BC has a slightly wider track because of the pneumatic wheels. Otherwise, they handle alike and are mututally just as difficult to sit in.

testing

The first few test runs of BurnoutChibi were done indoors, in our Conveniently Circular Building hallway. Due to the extreme acceleration ability of the vehicle, I couldn’t really test it any faster than DPRC or original Chibikart, so we decided to not take video. More testing commenced in an underground garage, then our usual spiral parking garage haunting ground. Unfortunately, I really only got a minute or two of hard driving in before the left motor threw several magnets.

The high speed of the motor caused some serious sparking as the loose magnets scraped the stator and also cut up the motor leads. Unfortunately, the only video that was taken was not focused properly…

The accomplice vehicle is the (still unnamed) tricycle.

Since that test, I’ve reglued the magnets and repaired the wiring, and BC is currently operational. I am currently waiting for a day in Boston / Cambridge when all hell is not breaking loose (in fact, as I write this) to test in the garage again. These pictures and videos will be uploaded when they are taken.

Chaos and half-assembled karts is the law of the land as the “Milestone 7″ checkoff and inspection draws near. This is a full “rolling frame” demonstration – brakes must work and steering must be hooked up and functional. The vehicle mechanicals do not have to be final, but to get to this point, it’s sort of implied. Hacking systems together to pass the inspection was discouraged, and nobody really tried to push anything sketchy. After MS7, the only tasks remaining should be to finish up electrical assembly.

At this point, things were being raised onto wheels and the true creativity of the students began to show.

This thing, for instance, had a custom wooden coachwork/centerpiece which was partially CNC router machined and also featured living hinges laser-cut into thin plywood.  On top of all that, the steering isn’t a normal wheel or handle, but it’s tilt based. The builders, Nelson and Carolyn, both have blogs and I swear they add content more often than I do. This creation has been officially named Zoran, which I briefly confused with Zorak.

Some of these things are conventional, others just a little off the wall, and still others… well, they have interesting operating postures. I’m kind of glad to see that nobody is really building a normal 4 wheel kart – there’s really only one. But hey, that’s not bad either – last year, the most normal and innocuous vehicle was done on time, on budget, exactly as described, and performed reliably.

Other vehicles are defined by a central feature, such as Dat Wheel.  That’s a 18″ lawn tractor tire that the team specified off Surplus Center. You’d  basically be sitting directly over it.

So that’s a sampler of the oddball creations coming out of this crew of MechE sophomores. What’s next for everyone is putting electrical systems together. I’ve been giving short “mini lectures” about places to get electrical parts such as switches and contactors, and also good wiring practices and other safety-related device (such as in the background of that picture – no male-side connectors allowed on batteries!)

In about 3.5 weeks time, everyone will once again (hopefully) fly down the service road and up the garage. This year is going to be tremendous.

On my end of things, I’ve been recently tasked with creating a relevant homework assignment for the EV students. One of the homework assignments for 2.007 proper relies significantly on you having built a competition robot. Since none of the alternate lab section students have, everyone was a little distressed. I therefore had to invent an alternative.

My alternative is a miniature (1-3 amps) current mode controller for a DC motor. That’s right, your homework is to torque control. I created the hardware hookup most of the way, requiring students to read a datasheet or two to discern what else needs to be hooked up, and also how to read the DC current sensor. The half bridge is standard fare for me – an IRS21844 gate driver hammering on some obsolete but sufficient IRF2807 N-channel FETs. The whole rig is synchronous rectified by nature. Really, this can be scaled up 100 times and be fully legitimate plus or minus some power supply changes.

Once the students finish said homework, I’ll release the working code & “class solution”, which is the most documented and commented thing I’ve ever written, as a general resource.

Here’s a picture of testing the whole setup, with a DC motor plant, ammeter to verify output, and a battery which can take regeneration current. Power supplies may be safer to hand off to a fuzzy duckling, but they cannot handle regeneration current, so a 10 amp fuse in the test battery will have to prevent things from going too awry. The controller is based off a simple integral-only (i.e. ramping) loop, which is more than suitable for driving highly inertial, dynamic loads like a vehicle.

So that’s explanation for the video last week! What really happened there was that I was pushing 15 amps (at 20 volts or so) into the field winding of the large blue motor (it’s a “separately excited” DC motor, so the mini half bridge board could crank 5 amps (briefly – I raised the limit just for the video) into it and have it just barely spin up. No, it is not creating perpetual energy. Without the torque control loop, it would have grenaded instantly.

From here out, I’m only bumping the students in the right direction to finish, and also making sure the appropriate paperwork and signoffs are in order for the final contest. In other words, “Wait, you want to do what with the garage?” “Yeah, we did it last year.”

The first thing I had to do to build a new Chibikart is to disassemble the old Chibikart. Here’s the scene of the crime:

This work left me with a pile of redundant electricals – namely 4 more Jasontrollers and the massive A123 B456 battery. Needless to say, these will probably find their way into some other silly rideable thing.

The plan for BurnoutChibi’s electrical system is actually to use my left over 10S 5Ah lithium polymer packs, instead of making a custom pack or keeping the A123 pack. I decided to this mostly for the power and energy density of the lithium polymer packs (Chibikart 1 weighed 53 pounds because the big A123 bus battery module weighs almost 20!)  as well as the simple fact that said lipo packs have been sitting for almost 2 years, and I really don’t want to see them go to waste. The lipos themselves are from the erstwhile Deathcopter, so BurnoutChibi will surely be the health and well being hazard I envisioned it to be.

The first appendage to the old frame is the new style brake pedal. At this point, I haven’t even removed the old steering linkage yet, but I wanted to see if it would interfere with the new position of said linkage.

I started from the rear with fitting the Vex Ball-shitter transmissions onto the “goalpost” mounts. This whole ‘rebuild’ is essentially replacing Chibikart 1 frame plates with specially crafted DPRC ones. The only difference between this rear corner and DPRC’s is the goalposts!

I focused on getting the motors mounted and the rear end together. Here, I’ve mounted the NTM motors to my NTM-to-CIM converter plates. Eliminating units, the result of this evaluation is something which is basically like a CIM, but 4 times more power dense.

There’s only one problem. The NTM shafts need to have a 2mm keyway cut into them so I can easily used the keyed bore supplied with most FIRST OEM parts such as the Vex transmissions (The fact that I can say “FIRST OEM” is unsettling).

As it turned out, these shafts are casehardened. Wow, Hobbyking, you’re classy now – what this meant was I could not use my single HSS 2mm endmill to machine the slot. Instead, I went on eBay a few weeks ago and bought some 2mm solid carbide endmills. I recommend keeping a set of carbide cutters around for dealing with troublesome materials; the downside, of course, is that they are more brittle and need a stiffer machine setup.

I faced the slight issue of the endmill being too short and the Bridgeport spindle being too fat to reach the nether regions of the  motor. So I did what any self-professed machinist wouldn’t do, and chucked it up in a drill chuck. In my defense, I bought this integral-shank keyless chuck just to do dumb things like this.

I cut the keyway just a little short of actual dimensions because the NTM shafts were not long enough to use the included retaining ring with the gears. So I had to press the key in,and will need some creative gear pulling if I ever wanted to remove these gears.

And here they are mounted. I found the sheer number of hexagonal sockets on the gearcases a bit confusing at first, but now appreciate how versatile they can be.  Chain tension is adjustable using the slightly slotted mounting holes. I inserted locknuts (nylocks) into the opposite side hex sockets, so torque retention will be positive.

Notice how the seat mounts have been turned around. This was necessary because of how big the gearcases were. The seat mounting centers, and overall position, will remain unchanged.

Crawling up the side of the vehicle, I reached this build’s star attraction: The gear shifter. This came together amazingly well, and the feel of the ball detent plungers is extremely satisfying.

Heading up front, I popped out these new steering knuckles. In keeping with the tradition of doing the least possible work, these were specifically designed as drilling operations in a 1″ aluminum square barstock. The four flange holes will be where the drum brake mounts.

Continuing work on the front end, the drum brake mount has been attached and the new narrower steering…ears? are mounted. I’m not sure what to call them on Chibikart. They’re too short to be A-arms or wishbones.

Recall the new steering linkage arrangement – the crank arms are basically socket wrenches that fit over the hex head bolts. Motion is transmitted via giant set screw in the steering knuckle. To ensure positive engagement, I machined a deep flat into the hex head bolt shanks and picked flat-bottom set screws to maximize the contact area. To retain the crank arms, I center drilled a hole and threaded it for a retainment bolt. Otherwise, the crank arm is thinner than the bolt head and will be free to float about 1/16″ or so.

I moved on to chopping up the 90mm drum brake to fit up front. The mounting method I ended up devising would have been fine with keeping the giant torque arm, but the design would be cleaner without.

To maintain the cleanest possible lines, I brutally slashed the housing with a Dremel cutting wheel.

To attach the drum brake itself to its mount, I first had to machine the little round spacer which adapted the 14mm bore of the brake housing to my 1/2″ bolt wheel spindles. I sandwiched the brake housing between the mounting bracket and the spacer so it was reasonably centered. Next, it was a quick drill press job using the mounting bracket holes as a drill template. The steel housing on these brakes is just thick enough to hold a few threads of #10-32, so a socket cap screw was screwed directly into it through a standoff.

The mounting bracket itself involve one sheet metal bend to create a spot which will eventually anchor the brake cable. Well, I managed to bend it the wrong way the first time. Heating up the aluminum with a torch and carefully bending it back the other way worked, but the metal still cracked on one side. I had a buddy on MIT FSAE lay a quick TIG bead across it (see the irregular texture where the sheet metal arm bends left).

The brake drum mounting itself is what I’d call “kinematically suboptimal” very nicely. Basically I squished the slightly tapered stamping flat on a hydraulic press to get a flush mounting face on the bottom side. Then, two standoffs which each have a small shoulder that is precisely fitted to a mounting hole keep the drum attached to the wheel. On the top side, the standoffs have a 1/4″20 thread so I can use already available button head screws to retain the rotor. On the other side, the standoff is tapped M6 X 1 to interface with the original wheel lugs bolts.

The concentricity, needless to say, is less than stellar, but turned out way better than I had anticipated. I’m likely to replace this whole rig with a custom machined aluminum dish that has M6 x 1 holes tapped into it so I can just dismount the whole tire without causing loss of alignment. The brake does scrub, but only slightly and intermittently, and works very well otherwise. I have no doubt that this thing can lock up and skid.

And the front end is basically together.

Work now will move to the rear again with assembling the drive wheels and sprockets. I have an order of brake cables and associated parts coming, so I hope hooking up the whole drivetrain and shifter this week is a possibility.