[6.10.20]  Plague Times Are Strange Times

Hey Dane, what have you been up to during the plague?

This page serves as a periodically updated list of things that I've observed and worked on during the 2020 plague. Many of the opinions and observations are just that, opinions and observations. I generally keep thumbnails at 300x300pixels, but this story is best told with images, so they are a bit larger than normal. Sit back and enjoy.

MIT Closes Up Shop Masks On Go Kart Time Makeshift Drive In Hiking and Exercise 360 Video Conclusion Image Directory

Some Background
I very rarely do story format writeups, but these are presenty odd times so why not try something different.
For those reading this in the distant future (the year 2000),  A pandemic hit the world in late 2019 / early 2020, some countries faired a lot better than others. Unfortunatley the states handled it poorly. Impressivley poorly.  Misinformation, uncertanty and a just-in-time supply chain were a fairly bad mix, resulting in a lot of really odd scenarios. I'm a nuclear research engineer, and I work in Cambridge Massachussetts. As you may have observed 

It begins: MIT closes up shop
From my perspective this got real in early Feburary. Cases just began filtering into the states and working @ MIT (a fairly sizeable group of folks working in relativley tight quarters) was curious. There was not really any guidance, just things brewing early on. It was just under two months into the spring semester, so things were in full swing, but there was an air of uncertanty. 
Getting some space for sanity, quickly:
With the "undergrads out in 3 days" decree, I gave a hand where I could. Had I been in that position I'd be faced with a 'where the heck should all my stuff go' problem, should my cutesy fusor end up in the recycling bin? What about that boat anchor of a power supply?
I managed to get some lightly-used basement / storage space on Albany Street set aside for temporary storage for Nuclear Science undergrads / RX operators. It was fairly well recieved, and got some utilization.
A guy with a Jeep
Let me paint the picture. Its cold and a bit rainy (of course its rainy). A couple hundred people are trying to re-locate, and cardboard boxes are at a premium. I ended up helping a few folks re-locate things down to 'temporary' storage on albany street. Jake Miskie was kind enough to document this zoo a bit more thoroughly here [link].
Creative Parking and a slew of emails.
It was kind of funny how many sporadic emails looking for storage occured during that period of time. Some Course 2 compatriots had half completed projects looking for homes, some of which ended up crated at home in my basement for the time being. The departure from campus was eery, everyone knew it was going to be hectic, but no one really wanted to interact in groups due to the many unknowns present at the time.
As you may know, i'm fairly involved in a group called MITERS. Shown right is the end-of-times party at miters before everyone scattered about the states.

A number of miters denizens live over at East campus. With the short-notice from admins of  'we're closing up shop', nearly every u-haul and rental vehicle evaporated in a fairly sizeable radius. Given that it was barely half way through the semester, a few EC folks decided to just rent a combined house out east. This began the east-campus invades cape-cod expedition. Shown far right was a great bumper sticker summarizing the year ahead. 
A surprisingly good email

I checked in with Radiation Protection group to borrow their rather giant van. @ "Adding the EHS van to the GET FIT Program", the GET-FIT program [link] is an MIT exercise program where you log your exercise time and win... I think Dunkin Doughnuts gift cards? Either way, this worked out and forwhatever reason was entrusted with a large van. 
With newfound access to a radiation protection van, thanks to the ever-excellent Bill McCarthy it was time to load up.
 Lets take a step back here, like most campus vehicles, this particular vanagon spends a majority of its life parked. Now it was going to take a voyage down to Cape Cod and back. I cant thank Bill enough for lending this chariot out during those curious times. I checked the oil and transmission fluid levels, and was mildly envious of how little use this vehicle had seen. 
So we loaded it up with 'essentials' for the trip down south. Bicycles, plants, food, textbooks, and the like all got piled in over the course of 45 minutes. A few colleagues and alums brought over their personal vehicles to help ferry what did not fit in the transport van. Something like 16 undergrads stuff was packed in.
The armada of assistants.
Friends and alums pitched in to help move folks down to the cape. I think shown is the Austin B mobile and an alum pickup. 
We got a quick group photo and headed east. Keep in mind this was March, so concepts of everyone wearing a mask, gloves or keeping distance was still being worked out. Nominally the known cases in the area were in the dozens at this point, stemming from a recent biotech conference. 
Had I mentioned that this van was basically un-used. It had acrued 8009 miles before departing (and a transmission warning light). Have you driven a tall van on a windy day before?  Neither have I. One of the cape-cod area bridges was especially windy, which made the ride all the more interesting. Transmision warning light seemed to be dependant on fuel-tank level which was curious.

We got to cape cod un-scathed, and proceeded to unload everything onto the lawn so I could head back before the sun evaporated away. There were many things, but also many happy-to-have-found-a-home people. 
On the ride back I stopped by a grocery store, mostly out of curiousity to see if the panic had set in way out on the cape. It was interesting, Milk, Bread and Yogurt were gone, but everything else was there. I think I counted three folks wearing face protection, I was wearing some spare purple lab gloves and a mold-over vented N95.
Got back to Cambridge, paid $20 for some diesel (This van hides the fuel door behind the passenger door, which took a solid 5 minutes to find).  I promptly returned the van to its sleepy corner of campus.  Wow I couldn't believe that worked as well as it did, but it did. I got back home, took a shower and proceeded to flomp. I didnt do anything particularly strenuous, but for whatever reason the anxiety of the unknown really chews through energy efficiently.
At home I was happy that we got the moving done, kinda curious to see what the subsequent weeks would be like. A return to normalcy, or whatever that would be, and whenever it would happen. I was admittedly anxious, I took precautions, wearing gloves and a mask throughout the whole trip but, information about how the plague spread was not fantastically available. Spent the rest of the following day cleaning and organizing the miscelaneous home hardware.

Gallery of images from the Cape Cod Excurison [link].

Masks On
I initially got involved with what would become the maskson program via Habib from e14/media lab. There was an email sent along about a plot to turn sucba hardware into emergency PPE. Initially I was a bit dubious of this working, but its important to consider the particular time this occured.
MIT was closed, along with all the labs and fun people. I reached out to be a part of some of the more formal MIT support programs but was ignored
Everyone was stuck home, waiting around indoors for news, which was mostly just uncertanty laced with confsion. This was, at least to me, a productive distraction. So i got involved.
Using Irobot filters as part of emergency PPE
Part of the brainstorming process was thinking up alternative mechanisms for providing protected air to the user. I had used some irobot filters for providing cleaner-air for a control cabinet, however the idea of using it as PPE was interesting.
How do you test a respirator?
Having worked at the NRL for a while, we periodically get fit-tested. This is a fairly straightforward process where you wear a test fixture and move your head around and it verifies a seal. I poked around and the one used on campus had been re-purposed for covid research activities. I was ware of a broken one, hiding in a closet and figured i'd give it a ago at fixing it. A few hours of dorking later and i was gettig nowhere. The unit uses IPA alchol as part of its process.
Super IPA
I had a thought that the IPA purity was possibly a culprit, and through some series of excellent events a vial appeared, freshly run from a nearby campus. 
I got it nominally working (albiet somewhat questionably repeatable)

"Go Kart Dad"
I think we could all use some good news, and this one is great. A good friend pinged me regarding one of his relatives working on a homemade electric go-kart with his kids. I was on-board immediatley. As you may have known, I'm a fan of derpy small electric vehicles.
To preface things, at this point getting things in the mail was sporadic and shipping times were all over the place. I had a number of battery modules and associated whatnottery at my home-lab and quickly determined that they were better suited being put to use.
"36 volts"  
One of my favorite battery related things is the magical 36v operating point. Its rare that things sub-divide this well while matching up with the de-facto lead-acid topology.
Chemistry Configuration Discharged Voltage Charged Voltage
Lead Acid 3 x 12v batteries in series 33 43.2
LiFePO4 12 Cells in Series 30 43.2
Li-Ion 10 Cells in Series 30 42
Li-Ti 16 Cells in Series 30.4 41.6
12 Cell Big Battery Blob
I was gifted four of these from a colleague, they are 12S-3P K2 systems custom packs, with an onboard relativley low current BMS. This is roughly 9AH at '36v', and plenty of runtime for a small electric childrens gokart. The onboard BMS should also protect against overvoltage and undervoltage, which should keep them fairly safe. I reccomended a simple 42v scooter charger (2A) from amazon as they are fairly ubitquous, but nominally to keep an eye on it while charging . not charge unsupervised. 
Electrically Loading the Unknown Pack.
Without knowing much about these packs, or their onboard BMS I decided to run a quick load test. The motor controller is rated for 22A, which was do-able with my 2.5kw load. I set the control current and let it sit for 10 minutes at what should nominally be the highest power the pack sees. Realistically its unlikely that the cart could accelerate and hold the max current continuously, I think the closest condition would be driving in a tight circle for many minutes which is probably in-feasible. 
Note these images were taken with a Flir E6, so the resolution isnt amazing, however, you do get a good idea for thermal buildup.The purpose of this test was to determine if the battery, and more particularly the battery management hardware, would stay reasonably cool during its use.  After a 10 minute 22A load test, the controller sat at a mild 107F / 30C, starting from an ambient environemnt of 80F / 23C. The pack was officially ready for gokart-ing. Note that a 22A controller really only sees that current when accelerating from stop, the actual current consumption at top speed on level ground is probably closer to ~10A, or ~400W. This pack should provide about an hour of runtime.
The Kit controller
The kit came with a 22A controller, and is the generic 'jasontroller' configuration. Large array of TO-220 through hole fets on one side, heatsunk to an extrusion case. Unfortunatley, as many jasontrollers are, nothing is labeled, as a bonus, the only easy to identify cables here are the motor sensor, the three phases and the battery input. The throttle was non-standard 5 wire, and there were a pile of 'extra connectors' of confusing purpose. I cant believe they sell an undocumented blob of wires. 
So, starting off i did notice an LED indicator silkscreen. A majority of these controllers actually are born to have a status-led, or blink codes used to determine what the controller is up to. These can be handy for diagnosing a failed throttle sensor or an undervoltage state. Lets tack on a small 0805 LED. And by 0805 LED i meant big through hole led because I was out of eaisly accessable smt LEDS. With some status info, now it was possible to sort out what the controller thought it was doing.
Digging around to find the bus voltage feedback.
To change the undervoltage cutoff, without access to the controller firmware, the only option is to trick the controller into seeing the correct voltage. To do this we change the resistior divider. I started by feeding the controller's DC bus with a fairly stout power supply. With everything connected (motor, throttle, controller logic power switch, motor sensors) I slowly ramped the throttle to verify the motor was functional starting at '48v'. Note that when running a BLDC controller from a power supply, almost every bench supply is single-quanrant, meaning it cannot sink power, just source power.
Finding thresholds
With the controller powered up from a bench supply, i tacked a small sense lead to watch what i believed was the controller voltage sense point. I found that at 42v it cut out (sense point 2v), we needed to adjust that to be closer to 35V, to do that I added a parallel resistor across the positive side of the feedback circuit, 12K was enough to bring the sense point for undervoltage cutout up to 2v at a battery input of 35V. The battery pack had its own undervoltage cut-off, however its way less stressful to have the controller cut out first, than try and interrupt 20+A at the bms.
Lets make sense of this thing
I put together a rough labeled diagram of the final setup. This made it easier for the go-kart installation, as I was not going to be there for the first spool up test. Quick video of the spoolup and the go-kart in action below.

A quick motor controller test and the final product
After the modifications to their stock controller to get it to operate at a lower battery voltage, I recorded a quick video clip showing the simple functionality.
A few weeks later the following wonderful machine was born:
Great job guys! More details of their build are here: 

"Drive In Movie Night"
Around a month and a half into the pandemic, the idea dawned to do a socially-distant drive in movie night. Everyone could stay in their own cars, audio recieved by radiowaves, what could be better.  A diy-drive-in is actually incredibly simple to do, but requires a dark remote place. The pandemic mildly restricts drive ins because, bathrooms are less accessable. Stores are not open, and at the time bathroom sanitaryness was an open question. We dug around and found an industrial park that was nearby enough and dark enough to work.
Advert for the evening shown right.
I didnt get a good photo of the setup, but nominall the projector was a model XYXYXYX and I used a greenworks 36V 400W inverter, tied to two 12S LiFePO4 ebike packs. Each pack is ~350wh, and an anderson parallel adapter was used to increase capacity. I used a normal pull-down projector screen, however, I forgot how good this projector was. We left the screen up and projected the side of the frame onto the 53' shipping container. Next time a cloth projection screen would work, interestingly it looks like 'outdoor movienight' took over ebay, and screens are only available in either ginormous or comically small size. 
We watched one of the greatest movies ever made, TURBO KID. Everyone had a blast. Right before the end, heavily murdery scene a rent-a-security guy appeared and asked us to stop tresspassing. Still was a great time had by all. Also the pixel-phone's night vision mode is amazing. Shown is an impossibly good image of the setup, thanks Fred. 

Hiking and exercise
After a few weeks of working remotley, loosing track of time and being a bit wound up I tried a 'work from home but outdoors' day. Its late March, undergrads were all kicked out a week and a half ago. Its still cold, and everything is uncertain in the aether.  I hopped on my derpy home 'mountainbike' ebike, which is admittedly less used than the roadbike or the newer mountain ebike, but it works. I brought along with me a folding chair and a backpack of snacks.

I live outside of the city, aside of some dog walkers,  its fairy quiet.
The first voyage out to do some exploring happened in late March. I had been home and abiding by the keep away from everyone rule, but given the remote-ness of my locale, some exploring with PPE persued.
Exploring local areas
The park and nearby woodlands are always a treat. This spot in particular is a favorite as it looks out onto the resivour with a farily open view. In early april there's not enough thermal energy outdoors for the flies and mosquitoes to awaken so its a fairly excellent experience overall.
Mid April brought some late snow. For whatever reason I enjoy running in bad weather. It was impressivley silent out on that snowy quarantined morning. Its unfortunate my robot snowblower was hiding near the city, so shoveling here was a manual exercise. 
A first attempt at work from home,  outdoors edition.

It was late april so things were still cold outside I had a 10' x 10' ish tarp and rope, and was tired of being cooped up in an apartment so i ventured out and made an impromptu remote office. I dragged along a camping chair, 
I had along with me a 12v thermos and a small 12v LiFePO4 battery module. This provided some hot water for tea. The spot was alongside an out-of-the way trail and a few dog walkers said hi. After around an hour it began raining. Interestingly folding camping chairs do little to keep your bottom from freezing off.
I later found some more interesting work from home, albiet outdoors spots.
There was a really interesting pavilion hiding as a remnant from some depreciated campsite. It had two large picnic benches and a surprisingly non-leaky roof. This was way better than my dodgey folding chair and a tarp.
Work from home outdoors tips and tricks:
I found that some simple things to bring along make a big difference. A small cloth tablecloth, a few snacks, handwipes and a 12v thermos to make some tea made the outdoors productive. Later on i brought along a modified greenworks 300w inverter, which makes an excellent ebike -> 110vac converter. I also dragged along a small 'desk fan' for those warm days. The view from my 'desk' was quite excellent.

360 Video Adventures
I had this idea, where I wear a 360 video camera and go do some longer trek mountainbiking / exploring. Seems simple right, put camera on head go biking right? As it turns out the gopro 360 that I used was a peculiar beast, the fusion 360 is an earlier variant, which opted to do all its meshing off-board. The process for going from footage to embedable video is fairly cumbersome. I documented some of the trials and tribulations here: 

MIT Reopening Round 1
Getting researchers back in
Getting tested twice weekly
Some interesting observations while on campus during this time

Disabling communial devices waterfountains and watercoolers are either turned around to discourage use or wrapped over / spouts removed. 
Oh how I missed the hobbyjet

Hardware installation & shipping logistics. 
Lets start with some back-story. Some time in 2014 the hardware for an upgraded controls system for the MIT NRL was submitted to the NRC. fast forward to late 2019 and it was approved. Here's the submission in all its photocopied-pdf glory:  [link]
Interestingly there's a timeline embedded into the installation, 180 days. This is probably to ensure that approved upgrades happen in a reasonable timeline but its not terribly clear. Unfortunatley that 180 day window started right around when Wuhan was experiencing the begining of the pandemic. An extension was granted, but upgrade season had begun!
What is being research staff at MIT like during this time?
The return to research was broken into three phases, the first of which had little guidance on covid testing intervals. I opted to go at least weekly, but the testing interval wasnt well defined for phase 1.  Building access was restricted to only the building you absolutley need. By this period the personell who were on-campus residents had a once weekly requirement. During research ramp-up phase 1,  MIT medical had its hands full, trailers were setup for testing, and the actual 'get tested' process changed a bit over the phase 1 / rampup.
Getting a covid test process part 1:
Getting a covid test process part 2:
This process involved removing a bunch of legacy hardware, identifying abanded cable runs, removing things, documenting, labeling, cabling and the like. Realistically this compounded by issues of hardware abandonment, when items were removed from service its nominally less intrusive to simply leave that hardware / cabling in place, instead of removing. Integrating that practice over decades resulted in a lot of abandoned things. Documenting and removing those things were laborious to say the least.
Interesting artifacts
While removing some ancient picoammeters, way on the bottom of a rack cabinet there was scribbled "This Sucks" with some very vintage grease pencil. Clearly the last installation had its trials and tribulations. I added a new sticker for whoever ends up doing this process again in the distant future.
Legacy instruments that were removed ended up piling out on a table outside of the control room.
Slowly it grew to a bit of a cauchophony of elderly technology and miscelaneous gray wires.
Oh how i missed the hobbyjet


(There's other photos in the photo gallery)
Concluding Remarks:

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Stay safe when working with electrons in aqueous / semi-aqueous environments. Also wear sunscreen, I'm not responsible for your newly aquired winter-farmers tan : ]

Rensselaer Polytechnic Institute 
Electrical & Electrical Power