Category Archives: Uncategorized

miniature things research (tiny steppers!) / start-lolling, start-trolling, start-rolling

stepper motors
I started looking into how tiny and cheap steppers can get, since micro servos are in the $2-3 range, and holy lady hexapods they can get tiny.

 More info here.

Turns out most tiny steppers come from vehicle dashboard instrumentation. To actually buy them
you don’t turn to mcmaster

Instead, a search for “nano stepper motor” reveals this:

More info here, including the fact that this stepper can be driven directly by an Arduino. 
On amazon, these cost ~$2-3 each as well. (search for “stepper motor gauge”).
I just order 6 for $16.50 to have some hand to play with (randomly ordering the micro-servos a while back turned out well); we’ll see how this goes. So, upcoming tiny stepper gantry?
Some more reasonable 15 cm ones cost ~$15 (vs the price on mcmaster…)

flying things

from the facelols, charles seyz

i think these days about $150
for the average kramnik  kopter
frame: $20-30 from HK. motors: $10each. esc: $15 each. kk2 board: $20
i guess add in radio and gaudy lighting too so $180-200
if you are fine with small
less than $100 is definitely possible
tinycopter runs like $7-8 motors and $8ish ESCs
the frame was made of a few 3d printed doobobs and carbon fiber
you can get CF sticks cheaply and i’m sure the 3dp stuff can be replaced with lazzered parts

this is why i am considering it:

i think flying things are an example of neat engineering
but that’s [$180] too expensive to justify
if it were in the $80-100 range
for a reasonably robust multicopter
that could be reliably produced (not made from chopsticks)

current commercial options,  which are super-slick and $150
(hattip shane)

Uweh. That is SO AWESOME. Actually now I am not so sure there is much point trying to drive the cost down to $80 or so with reusable parts. Then again, if the kits are derpy enough, they should encourage people taking the course to go forth and build better versions.

In theory, tricopters would cut down on costs even more (take out a motor, propeller, and ESC). But something about they are more mechanically complex (extra component, servo rudder)? I might be confused here.

for research, here are some small quadcopters my friends have built: by scolton
hi shane
hi charles

what is this all about?
in my pursuit of excessive feedback / encouragement wherever I can find it, I input to 100k coaches corner (sort of questionable since I have no intention of entering the 100k ~_~) yet another description of what I intend to work on:

Khan academy / Udacity with hands-on mechanical engineering projects, fully kitted so no fabrication resources are required, aimed at high school+university level.

the current plan is to have three projects, a micro-robot arm, a nano-quadcopter, and a nano-stepper gantry. (Maybe some swarm robots? What other buzzword robots are there? Anyway). Realistically I would be happy just running with the first one, since the timeline is so short (six months until I run out of health insurance). But it’s fun to think about the other two/three/infinity.

idk why I feel so awkward about pursuing a startup full force except that my group of friends seems to have a reactionary “too cool for startups” attitude .__.

misc. info
health insurance after graduating
I’m in this awkward position where I cannot get coverage under my parents. Given my recent spate of issues after a lifetime of not needing to go to the hospital, insurance is a good idea (plus, it’s mandated in MA). Therefore:

“Your MIT Health Plan coverage continues through August 31”

Ouch, so the FSA (no strings attached MIT accelerator) ends on the 21st with a Demo Day on September 7th. By which point in time it’s most likely I’ll have decided this won’t get to the scale I need to sustain myself and look for a full-time job, but just in case:

bcbs I / II 

“you must apply before August 1 for your new coverage to be effective starting September 1.”

Uhm, what, I have to call to get a quote. Meh. Looks like in the range of $200 a month as of three years ago.

research: fixing titanium glasses =__=

i just got these glasses
i swear i didn’t step on them. maybe i was eating them in my sleep or something -__-;

anyway, i have contacts but dislike them, i can’t deal with having a regular sleep schedule and everything always feels a bit surreal / blurry

so here’s some research on eyeglass fixing / making:
Front frame lasercut out of cellulose acetate, with the intention to heat the sides and bend them back. Wonder if he/she ended up completing it
Well, some lasercut frames, not so interesting to me
lasercut sunglasses
!! all the things about welding titanium frames

Okay, hopefully I will do things like apply to jobs this weekend and Monday go in with a clear plan for fixing these. I want to try spot-welding them, it actually broke in this really convenient way that I can try welding it and if it fails I can still try to make my own leg.

Inkscape 42”x36” Scientific Poster w/ SVG source (Caffeine’s Impact on Sleep)

This is a followup post to Caffeine’s Impact on Sleep, Inkscape A0 Scientific Poster draft

Finished my 42”x36” poster today (turns out 2.671, my Measurement and Instrumentation class, didn’t want A0). I saw some awesome horizontal and vertical designs Tuesday, and now I have this super-cluttered and not very aesthetically pleasing poster *sigh* Oh well. I liked my draft version better for its simplicity and think I have too much text on this final version.

Larger size PNG image available on dropbox,

!! PDF version available (large file, ~10Mb), as well as SVG source!!

Again, thanks to Alexander Erlich for the Inkscape template
Also, thanks to netalloy for the coffee cup vector
And thanks to OnlyPositive for the picture of the sleepy cat.
Google Docs
Spreadsheet here. I calculated averages and stddevs with =AVERAGE( ) and =STDEV( ) respectively, and turned formatted time (e.g. 07:30:00) into decimal hours (e.g. 7.50) (also applied Format > Number > Two decimals) using the formula =INT(F4)*24+HOUR(F4)+MINUTE(F4)/60

Here is the matlab code I used. It’s very messy and I don’t actually understand what it means. In fact, I had to do post-processing of the Matlab > Export Setup > Rendering, Resolution = 300 > Export > figureN.png in the GIMP prior to dropping it in Inkscape to get the images I wanted.

caffeine4=[0 0 0 0 0 0 0 0];
sleep4=[6.95 10.87 9.75 7.52 10.95 9.43 8.75 10.23];
day=[25 26 27 28 29 30 31 32];
[AX,H1,H2] = plotyy(day,sleep4,day,caffeine4,'plot');

title('Phase 4: Daily Hours Slept and Caffeine Intake');
xlabel('Date (in April)');
%xlim([26 13]);

set(get(AX(1),'Ylabel'),'String','Amount Slept Daily (hrs)'); 
set(get(AX(2),'Ylabel'),'String','Daily Caffeine Intake (mg)') ;
axis(AX(1),[25 32 0 11]);
axis(AX(2),[25 32 0 700]);
set(AX(1),'YLim',[0 11], 'YTick',0:1:11, 'box','off');
set(AX(2),'YLim',[0 700],'YTick',0:100:700,'box','off', 'box','off');

    'Marker', 'o',...
    'MarkerEdgeColor', 'none',...
    'MarkerFaceColor', 'b');
    'Marker', 'o',...
    'MarkerEdgeColor', 'none',...
    'MarkerFaceColor', 'g');

Above code resulted in this graph:

This data was actually 25 April to 2 May, but instead of learning about timeseries in MATLAB, I just cheated and stuck “April / May” in the xlabel and used 31 and 32 to not break my code. I planned to post-process in gimp to turn “31 32” into “1 2” but forgot to do so.

For phase 3, I couldn’t figure how to get rid of the 20.5 and 21.5 tick marks when I expanded to graphs to reasonable size, so I did post-processing in GIMP. Here are the two images I smushed together into the third:

Misc. other tricks too lazy to document fully:
Using “shift-J” in Vim to turn newlines (ctrl-click-drag to get a column of values from google doc separated by newlines) into spaces, which Matlab uses to delimit vector data.

Making Instagram-like effect with kitten in top-left corner via kitten > right-click Add layer mask > (1) Gradient tool white-to-back, radial, click-drag from center to slightly past edges of images. This transparency-ed a large part of the cat face so (2) Ellipse select most of cat face, Gradient tool white-to-light-gray, radial, click-drag from center to edge of ellipse.

Inkscape, Filter effect > Make arrowheads match color to the lines. (If you decide to change the color of the arrowheads).

New Projects Blog

orange narwhals are awesome! I’ll post my CSS modifications to the Blogger template in a bit, and would like to attribute the orange narwhals I used for my background to the Ubuntu Natty Narwhal backgrounds. I’m in the process of moving worthy posts over from, which I’m converting into a documentation blog.

IAP 2010 — Trip to Rural Central Mexico (thanks, MIT GPI and PSC)

I haven’t blogged in roughly forever, mostly because I never got around to it. But I hope to start keeping a blog regularly from now on. (Maybe voy a practicar español y 中文 too).

Anyway, I spent IAP, Independent Activities Period, a special time during the month of January for MIT students, in a little town in rural central Mexico called La Vaquita (hur hur that literally means “Little Town”) as part of PSC-GPI (Public Service Center and Global Poverty Initiative) Poverty Action Team. This program was new for this year. I found out about it by attending a GPI General Body Meeting, checked it out on the GPI website, and then submitted a short application. A bit later I had an interview at the PSC, and then right before Thanksgiving Break (1 or 2 months later) I found out I’d gotten in.

Three of us went, Sam (Senior, Environmental Engineering), Sivakami (Junior, Bioengineering / Premed), and I (Frosh, Undecided between courses 2/6/20).

A little photo overview. I think I’ll post some of the funnier pictures in a followup post.

This was the room we stayed in. Yay we had beds!

Carla is part of our host family. We’re taking a short hike just outside of town.
We are always fed super-well. There were no restaurants so all the food is homemade.

We built an awesome ecostove! It’s a program of the government. Two holes for food, one hole for the chimney. Made from local materials and a bag of cement. This was done with a mold. 
We’re making a stove without a mold in Señora’s ovenplace! Sam, Sivakami, and I crawled in to help pound the cement mixture. The other kids did too, child labor ftw.
Some home food! Found on one of the rare occasions when we left La Vaquita and went to a neighboring town. It was really spicy for fried rice.
Yep, there electricity. Most of the streetlamps are broken though, and it’s not very fun walking at night because there’s lots of working dogs that are trained to bite at cows.
Oops, when we get locked out of the house we have to climb onto the roof and into the inner courtyard. This open-to-the-air architecture made our room especially freezing because (a) No heating (b) No door to our room, just a curtain. Think 5°C (40°F), probably less since we definitely got ice and frost overnight, freezing.
Our host mom. She’s pretty amazing and acts like a person twenty years younger.
Next to her are Bobby and Marado (I think that’s his name, it means brown or something).
Doing some laundry! Washing machines, but rinse cycle is by hand. The water comes from a well to one spigot for each house. Then take a hose and fill up the barrels (there’s one to the far left). Use buckets to withdraw water as needed throughout the day.
Do this in the afternoon if you don’t want to freeze your hands off. 
Hanging up some laundry yo. Don’t want things to fly off into cacti or dirt, and it gets pretty windy some days.
 Look at us, we’re working! (1) We called a town hall meeting. The paper is for ideas and such. (2) For our last meeting, we split up into groups and then got volunteers to present conclusions. CW from lower left: Sam, Carlos of Zacatecas who came down to help us out, Señor Martín, a prominent figure in La Vaquita, Franchesco, a prominent figure from a neighbouring village, and Francisco, a student at ITESM in Zacatecas who works on his parents’ farm on the weekends.

(3) Lindsey, ITESM employee and director of Study Abroad programs, Sivakami, behind her is Don Jesús, comissario of La Vaquita, and then the rest of the town.

Some beautiful scenery. You don’t get this at MIT, we’re in concrete city-land here.
Helping out with chores! Not really, we are cow milking novices. 
There was this sketchy part where the Health Team came to give H1N1 vaccines. The nurse guided us into giving vaccines and I, learning on the job with a questionable grasp of her Spanish, vaccinated maybe 15 people. Including babies. *sadface*
Homemade tamales for the win! Delicious, and there was this awesome warm milk (fresh from a cow, no doubt) + cinnamon drink.
Far left is Señorita María. She’s this awesome lady who gives a grandmotherly schoolmaster aura when she talks. To my right is a guy who, like many of the other guys in the town, will leave for cities to find work to support family. There sure aren’t enough jobs in La Vaquita. To the far right is the Promotor of the Health Team, Javier. He truly believes in his job. Carla is to Sam’s left, and then there’s Sivakami.
The doctor of the Health Team. This is the Casa de Salud of a nearby community.
The typewriter is new technology from 2009, before that they wrote documents by hand.

Because there were no public trash bins, trash was an issue. It’s really fun picking trash out of cacti… Also, like most rural areas trash was burnt because of lack of pickup programs.
Trash pickup day! Then we burned it all. There was still lots of trash left when we ran out of trash bags (they went fast), but it was a good start.

We spent 1 day sightseeing in Zacatecas, a large city (largest in the state of Zacatecas) about 3 hours away from La Vaquita by car+bus . We’re crazy workaholics or something, I’m not sure what drove us, but we had tons of fun and I wish we could have stayed longer.
Our family owned lots of cows. This is right behind our house.
At the convive, a picnic for us just before we left to go back to the States.
There’s a slide in progress there.

Did I mention the beautiful scenery?

We spent 3.5 weeks there and had an awesome time. Now we’re documenting all the possible future projects for other MIT students, such as biogas digesters, computer classes, solar heating of homes and water, etc.

Ooh, it’s light outside. And all the snow melted 🙁 So much for a crazy blizzard. Good night!

[2 Feb 2010: Temporary doublepost from as I sort out worthy posts]