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

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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…

…PLASTIC….

…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!

mini-Jasontroller

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

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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.

vanfan

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.