braindump, 3D Printing Research (from a year ago)

Last summer (while I was an intern at fitbit) I did a bit of research on 3d printers while considering getting a solidoodle, so this is about year-old information


Hi all,
(following is a long post, I decided to finally educate myself about 3d printers)

The 2 nozzle machines do not allow for support structure for complex parts.

In case anyone is interested, I consulted my awesome friend (who recently sourced 3d printers for a new shop space) about the resolution issue.

It turns out that resolution in the Z direction is less than in the XY directions so that can be used to differentiate printers. However, it seems that to some extent the limit nowadays on hobby machines is in software, not hardware, for z-axis resolution. In fact, usually (all?) professional 3d printers have to use steppers in the end, so they get similar resolution to hobby machines. Solidoodle and Makerbot Replicator can go down to 0.1mm (3.94 mils). I am uncertain but since this is comparable to listed professional layer heights, the main difference may be speed and lack of support material for overhangs and such.

The main difference between commercial (usu. 10k to 200k) and hobbyist machines(<$10k): one is designing for reals and 3d printing it, the other is design for the 3d printed cools and 3d print it. Partly resolution, partly speed, mainly “the problem with low-cost hobby printers for really professional apps is that they do not do support material.”

=======Technical Discussion (see below for background info)===============
From my friend Charles Guan on support materials:

Not even the [Makerbot] replicator right now does built-in support material, nor Ultimaker

or Solidoodle. If they really want something that they don’t have to think

about designing specifically around the shortcomings for, and especially for

protyping consumer product enclosures or internal assemblies, I think a

commercial machine is worth it [versus hobbyist printer]. Ultimately even $40,000 Stratasys printers are

stepper-driven and get the “same” resolutions.

On the topic of different professional printers,

If they want *sheer resolution* you still can’t beat classic stereolithography
(SLA) processes. Zcorp has the advantage of infinity colors, however. Depends
on if they want prototypes to be structural or not – zcorp prints won’t be able
to act as enclosures or test cases, etc. but SLA plastic generally can. Modern
SLA machines all use DLP to do a whole layer at a time so they can be very
fast. Downside of SLA is the open bucket of light-sensitive goo they use (which
tends to be really expensive, except for this new place which seems to be producing low-cost
variants, though not sure if a commercial printer would like that)

Otherwise, a hybrid of the two is Objet which we have on our
list of stuff to get. They essentially do UV-cured resin, similar to SLA, but
in a dry form (depositing only what’s needed). Both have much, much better rez
than FDM/extrusion. Can’t think of the numbers off the top of my head though.

On the topic of resolution (what resolution do you need for professional products?):

Depends on what you want… hair is usually 3 mil (.003). 0.01 is a tad rough,
you would see it very clearly. The makerbot Replicator is 0.27mm (0.0068) by
default. For professional product proto’ing I would try to find at least 5 mil
or greater. SLA (stereolithography) and Objets can hit this easily, I think. I have a “beast mode”
setting on the replicator which is 0.5mm (about 19 mil) layers if i am building
something square that just needs fast.

============Background Info====================
Okay, that was hard for me to digest and summarize because I didn’t have the background knowledge, which I present here.

First person pronouns
Industrial 3D printer manufacturers:
(manfuacturer name – printer name – technology used)

Hobbyist 3d printers manufacturers of note: (all FDM process)

  • reprap-based machines (tend to be finicky to setup and use),
  • Makerbot
    • (gen 1 cupcake, finicky and poor mechanical design,
    • gen 2 replicator, better designed and support for two nozzle head for multicolored prints)
  • Ultimaker – super light moving head for fast printing
  • Solidoodle
  • a whole host of others, including cake printer (candyfab), chocolate, rice krispy printer…

SLA, DLP, FDM — terms I’d heard before but didn’t know in detail:

(abbreviation, full term, summary, base materials, manufacturer)

  • FDM – Fused Deposition Modeling – Poop out lines of heated material that then solidifies (“molten polymer deposition”) – thermoplastics and eutectics – Stratasys
  • SLS – Selective Laser Sintering – Dump layer of powder, use laser to fuse parts to keep, repeat (“granular materials binding”) – thermoplastics, metal powders, ceramic powders – EOS
  • SLA – Stereolithography – photopolymerization to produce a solid part from a liquid – photopolymers – Objet
  • DLP – Digital Light Processing – photopolymers – Object
  • Z-corp – Powder bed and inkjet head 3d printing – deposit lines of liquid glue on powder, deposit layer of powder,  repeat – Plaster, colored plaster – Z-corp (exclusive)

Full[er] Explanations


A plastic filament or metal wire is unwound from a coil and supplies material to an extrusion nozzle which can turn the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism, directly controlled by a computer-aided manufacturing (CAM) software package. The model or part is produced by extruding small beads of thermoplastic material to form layers as the material hardens immediately after extrusion from the nozzle. Stepper motors or servo motors are typically employed to move the extrusion head. If required, support structures are automatically generated. The machine dispenses two materials – one for the model and one for a disposable support structure. The materials are deposited in layers as fine as 0.04 mm (0.0016″) thick,


Selective laser sintering (SLS) is an additive manufacturing technique that uses a high power laser (for example, a carbon dioxide laser) to fuse small particles of plastic, metal (direct metal laser sintering), ceramic, or glass powders into a mass that has a desired 3-dimensional shape. The laser selectively fuses powdered material by scanning cross-sections generated from a 3-D digital description of the part (for example from a CAD file or scan data) on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness, a new layer of material is applied on top, and the process is repeated until the part is completed.  Unlike some other additive manufacturing processes, such as stereolithography (SLA) and fused deposition modeling(FDM), SLS does not require support structures due to the fact that the part being constructed is surrounded by unsintered powder at all times.
According to, one machine, “EOSINT p390. The layer thickness of this machine is0.15mm.” (5.9 mils)


Stereolithography is an additive manufacturing process which employs a vat of liquid ultraviolet curable photopolymer “resin” and an ultraviolet laser to build parts’ layers one at a time. For each layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin. Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to the layer below. After being built, parts are immersed in a chemical bath in order to be cleaned of excess resin and are subsequently cured in an ultraviolet oven. After the pattern has been traced, the SLA’s elevator platform descends by a distance equal to the thickness of a single layer, typically 0.05 mm to 0.15 mm (0.002″ to 0.006″). Then, a resin-filled blade sweeps across the cross section of the part, re-coating it with fresh material
Stereolithography requires the use of supporting structures which serve to attach the part to the elevator platform, prevent deflection due to gravity and hold the cross sections in place so that they resist lateral pressure from the re-coater blade. Supports are generated automatically during the preparation of 3D Computer Aided Design models for use on the stereolithography machine, although they may be manipulated manually. Supports must be removed from the finished product manually, unlike in other, less costly, rapid prototyping technologies.


In digital light processing (DLP), a vat of liquid polymer is exposed to light from a DLP projector under safelight conditions. The exposed liquid polymer hardens. The build plate then moves down in small increments and the liquid polymer is again exposed to light. The process repeats until the model is built. The liquid polymer is then drained from the vat, leaving the solid model. The Objet PolyJet system uses an inkjet printer to spray photopolymer materials in ultra-thin layers (16 micron) layer by layer onto a build tray until the part is completed. Each photopolymer layer is cured by UV light immediately after it is jetted, producing fully cured models that can be handled and used immediately, without post-curing. The gel-like support material, which is designed to support complicated geometries, is removed by hand and water jetting. Also suitable for elastomers.

Powder bed and inkjet head 3d printing  

An inkjet-like printing head moves across a bed of powder, selectively depositing a liquid binding material in the shape of the section. A fresh layer of powder is spread across the top of the model, and the process is repeated. When the model is complete, unbound powder is automatically removed. [For some definition of automatic.. usual requires manual post-processing aka making a giant mess]

Random dump from class notes:
typical feature size — 10 mils. state of art — 1 mils. (lowe resolution than can machine parts). Slow! — hours to print small objects. complex — days.   
real point of 3d printers: nested parts and overhang — cannot do in mold [molding and casting procdess]. but need supporting material.
stratasys — water soluble primer
inkjet acrylic droplets — print with wax
dimension 3d printers — has two heads. raster structural and then support material and then next layer. temperatuer of chamber — below fusion temp and much higher than plastic flow so plastic sticks to itself.
have crypto on material cartridges — drm on plastic (can use cheap plastic otherwise). 10k mac shop [yea I don’t remember what this means] — fine but materials are appallingly expensive. Applies to any vendor.
tektronix phaser — inkjet photocurable acrylic. melt wax away to get part and then play with solvents to get wax completely out. fairly fast process b/c heads running in parallel and global uv flash. very nice finish / resolution for same reason.
dimesnion — little fdms — 10 to 40k. big ones, 100k.
InVision — 100k, and $100 for tiny part due to mats.

color 3d printers —
zcorp — everyone dislikes, because? they have powder bed (plaster), spreads layer of powder. straight inkjey heads from hp spreads binder. then powder, then binder. don’t need support material (use unused powder), and add color just in binder.
but disliked because binder does not bind very well. when done printing, try to separate bound from unbound, and sort of bound powder, and everywhere covered. post process to convince to really stick (infuse / dip in wax) together. color but no structure / surface finish. in theory just as fine as invision with droplet size, but due to messiness does not come close.

laser sintering — instead of binder, use laser to print. works with metal powder. issues: machines are alarmingly expensive (few hundred thousand dollars) and metal compacting is not very good.
metal 3d printing — force in metal (injection mold) and squish it. cost does not justify quality.  

Hobbyist FDM resolution

Best of all Sam Cervantes, the founder of Solidoodle—who clarified some of the technical points on their website following our post—helpfully contacted us to illuminate some of the murkier points of 3D printing resolution. As Sam explains:
… Typically the Solidoodle—and the MakerBot, from my understanding—print layers every 0.3mm (11.8 mils). At Solidoodle we’ve printed as low as 0.1mm (3.94 mils),

Now let’s talk about the resolution in the horizontal (X-Y) plane. The Solidoodle is capable of repeatedly positioning its printhead to within 0.011mm (0.433 mils) … but I did see that they [Makerbot] use 1/16th (62.5 mils) microstepping on their motors.

However, you can see how it’s a little superfluous to say that the resolution in the vertical (Z) direction is 0.3mm and the resolution in the X-Y (horizontal) direction is 0.011mm

… it’s important to remember that the printhead is extruding plastic through a 0.35mm (13.8 mils) nozzle. It’s important to remember that ABS plastic oozes and expands a bit when it comes out of the nozzle . Even though the motor on the automatic sprinkler may be capable of positioning the water nozzle to within millimeters, in the end the water is going to going to spray out of the big nozzle over a wide area in a somewhat random manner.

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.

weekend project: minimalistic servo arm

There’s a video of it in its final state, with its multitude of issues. *sigh* one day I will actually finish a project. Only the first and last 5 seconds or so are interesting. Cost: ~$6 for the two microservos (!! so cheap), plastic is free, then the board+microcontroller battery is $25+$15+free (probably $10?).

After building hexa-rideablepod, I have definitely been more inclined to daydream about small or fold-able or compact project.

I should update my project todo list.

I started at ~8pm on Saturday and finished ~3:30 pm on Sunday (and yes, I did sleep a bit, as well as watch an anime movie (Summer Wars) …

what the cloud looks like in the future

… and spend a lot of time reading about inverse kinematics and poking at IK code I never ended up using).

I was inspired by

The code looks pretty straightforward.

// Given theta1, theta2 solve for target(Px, Py) (forward kinematics)
void get_xy() {
  actualX = a1*cos(radians(theta1)) + a2*cos(radians(theta1+theta2));
  actualY = a1*sin(radians(theta1)) + a2*sin(radians(theta1+theta2));

I was a bit confused by the definitions of the variables, since I haven’t done kinematics in a while. In the forward kinematics part it is essentially saying:

measuring the servo spline outer diameter in order to create lasercut female splines on my parts instead of using the proprietary servo horns. I started around this time. I swear I spent like 30 minutes trying to figure out how many divots it has (21) before just trial-erroring it, lol.

It gets to be pretty late in the day after I try to struggle to remember kinematics.
Here are some beautifully written kinematics notes I found linked from stackexchange question on drawing robots (robotics stackexchange! i’m excited).

Well, crap. I hesitate — do I want to try to get something done and present a project or not? I eventually decide (and with some support from the awesome Jessica Artiles) that I may as well get more feedback on my ideas. What is there to lose?

Thus, I emergency hot-glued some potentiometers onto pieces of plastic and used that as my control ( a simple mapping of potentiometer values to servo values is all that’s needed) instead of writing IK code. This arm controller design was inspired by

img src my design inspiration, except mine was jankier and used more hot glue

near the end of the designathon

I didn’t even have time to map things correctly, because I thought the presentations began at 5pm but actually they began at 3pm.

The lasercutter files looked like so:

It’s hard to see the cuts. But the pots have flats on their shafts, so the pot arms have semicircular holes that are tightly fit onto the pot shaft to couple rotationally. And for a minimalistic design, the robot arms have servo splines cut into them so they mate directly to the servo.

I had the most issues trying to make a press-fit bracket for the servo so that I could couple it to a base. The sides of the servo weren’t particularly flat so the rectangular brackets always broke on installation; I ended up with a C-shaped bracked design.

a frontal image

Also, the servos are amazingly torque-ful. I thought the base would be enough to hold it down but I ended up adding tape so that the servo arm wouldn’t swing itself around.

Also to fix, I actually need to build a platform so that the base is heavy enough that the servos don’t push it around and high enough that at zero degrees the width of the servo arm doesn’t cause it to hit the ground.

I also actually did calculations for the servo, or rather used a calculator online, to verify the servos would handle the sharpie weight. Not that I had different servos or anything. (screenshot below)

Oh, another issue I ran into, the servo.write() arduino library uses modulation from 544us to 2400us, while the microservos used 500-2400 us, which gave me this issue where the servos wouldn’t go all the way down to zero degrees when I used myservo.write(0). I took a quick look at “arduino-1.0librariesServo” and found out thatyou can specify these min/max values when you initialize the servo, e.g.

attach(pin ) - Attaches a servo motor to an i/o pin. attach(pin, min, max ) - Attaches to a pin setting min and max values in microseconds 

There was some other funky issue with trying to read a sensor while the servo was drawing power. Turns out I just need more delay in my loop.

Can’t think of anything else for now.

Material Costs

ebay $11.88 
“4x SG90s 9G CYS micro servo motor RC Robot Helicopter Airplane Car Boat + Horns”
so about $3 per servo

The servo specs:

Pulse Width: 500-2400 µs sg90

Current Status:
I lost the code, and I broke some of the lasercut pieces, (the usb port for programming the arduino also seems to create a lot of sensor noise and the servo arm kind of did crazy robot arm thing and killed itself) so right now I re-lasercut  pieces and am re-writing the code. Should be up within a week.


Follows is a live blog of me working on drawbot:


ebay $11.88 
“4x SG90s 9G CYS micro servo motor RC Robot Helicopter Airplane Car Boat + Horns”
so about $3 per servo
let’s follow this tutorial
confirmation that 9g micro servo can indeed make robot arm: 
okay yay let’s do some math
thanks society of robots

alright, now let’s see some real specs on these micro-servos:

Stall Torque at 4.8 volts = 22.2 oz/in (1.6 kg/cm)

aww… so cute (compare to the 7 to 15 kg/cm ones used in “small” robot arms:

So what are the tradeoffs? With a longer robot arm length, I get more range, but then I suffer torque-wise.

Also, need 4 dof — one for the pen to move up and down.

some research into simulating robot arms online..,8076,898588-nav_and_content,00.html

my initial thought was to use processing, but oh hexapods java applets >__<

okay the guy next to me at the hackathon, idk his name, says i should just write it in html5
[edit: it may have been vincent xue]

excellent plan, learn html5

mmm kinematics libraries

wah html5 games
okay let’s not get too distracted

hrm kinematics in flash

i should catch up in 18.06, perhaps

okay, assume some weights
google: density of acrylic
1.18 g/cm³
thanks google

okay let’s make up some dimensions for a link length
4x16x3 = 192 cm^3 * 1.18 g/cm^3 =
thanks dot-gridded metric notebook and google

hrm, so about 1/5th of a kg. Wait what? that seems wrong.

oh units -> 0.3cm thick, so = 22.7 grams.

(from actual measurements:
15g for a 3*50*76 mm chunk, or 1.32 g/cm^3

okay now for
pre-built calculator!

okay not operating near stall torque, that is good

(conversion N m to kg cm is about x10, if you let gravity ~10 m/s/s)
okay, screw this, I am going to CAD some stuff
later: end up not CADing anything
One anime later, and back to staring at robots.
i start watching youtube stanford lectures but am too sleepy mmm canvas, 2010 2d robot arm simulator

hmm GUI via processing

oh! excellent written documentation

day 2
haha, still here. i’m so sloowwww at building things, all the other teams are so cool
okay i’m working by myself because i’m weird like that

eww, the servos are doing funky things where servo.write(0) doesn’t seem to go all the way to zero. let’s compare. hitec311 and sg90.

Pulse Width: 500-2400 µs sg90

Pulse Width: 900-2100 µs hitec311



   attach(pin, min, max  ) – Attaches to a pin setting min and max values in microseconds
   default min is 544, max is 2400

Adam Libert, DIY waterjet and crazy grad student, drops by and shows me cool robots:

serial monitor output:

º’j¤ º’jP ºŠjR ºŠjR º’jT ºŠjR ºŠjR ºŠjT ºŠjR º’jR ºŠjP º’jP º’jT º’jR º’jP º’jR º’jP º’jR º’jR ºŠjR º’jR º’j

Exciting, when I am commanding a servo, it pollutes the analogRead.
Well then.

Oh, I just needed to increase the delay (was using 1). Hmm. I’m not even writing to the servos. I wonder why initializing the servo means the serial loop can’t run fast enough.

how the heck does a kit for this not exist already?
$250, wow.

whee it’s 3 pm and i decided to pitch because I HAVE NO SHAME. 😀 It’s amazing what having the support of a friend can do for you.

MIT Founders’ Skills Accelerator 2013 application in non-form format

Ugh, the Founders’ Skill Accelerator application is in this dumb form format, where you have to fill out required questions on each page before seeing the rest of the application. I put in dummy answers and then compiled all the questions the application asks as of now.

In neat google doc form:

I copied it below as well, but too lazy to fix the formatting.

Teams should commit to work in the FSA office space for the duration of the summer (June 1-August 31), and present at the Demo Day on September 7.

Page 1
Deadline: Friday, April 5, 2013 at 5pm EST
Bio (2-3 students) for each of us

How long have you known each other, and what have you worked on in the past? (Include past work done on this project, if applicable.)

Will the team member work in the FSA space Room E40-160 in Cambridge, Mass. for the duration of the summer (June 1 – Aug 31)?

Page 2
Your Project
We call each team’s work a “project” to emphasize the educational nature of the accelerator.

  • What problem are you trying to solve through your project?
  • Tweet us your elevator pitch — give us your elevator pitch in 140 characters or less.

  • Page 3

Proposed Milestones (aka how your team earns up to $20K!)
What do you want to achieve this summer? We will work with you to create rigorous yet achievable milestones, but we’d first like to hear from you. Where do you want your team to be by mid-September regarding customers, product, team, and finances? (list 2-5) For more explanation about milestones, including examples, please go to

Proposed Customer Milestones (list 2-5 for each)

  • customers
  • product
  • team
  • finances
Page 4
Additional Questions
What inspired your team to get together and work on this project?

Who do you view as your competitors, and how do you differ from them?

Who is your target customer? (Hint: “Everyone” is not the right answer.)

Have you received any funding (including angels, family/friends, personal dollars invested, etc.)? Do you have any customers? (These two questions help us gauge your starting point, so don’t worry, there is no “wrong answer.”)

We will have a lot of applications for this program, so choosing our final teams will be tough. Why do you think you should rise to the top? What sets you apart from other teams?

Questions I need to ask:
Can I work out of IDC space instead (the MIT-SUTD international design center is a co-sponsor of this) of the E15 space?
Incorporation of media (e.g. video) into application?
Alternative resources (because way to hang by a thread until May 1st)?

Key dates:

  • Due Friday, April 5 at 5pm. (week after spring break)
  • Notified by May 1st.
  • Work in space for duration of the summer (June 1-August 31), and present at the Demo Day on September 7.


A select number of teams (in 2012, there were 26) will be interviewed in person during the week of April 22. Of the teams interviewed, we expect to select 8 teams for FSA 2013, but the FSA organizing team has full discretion over the number of teams selected.

So… odds are not great. Stipends are nice. Stipends will feed me. Maybe I should look into trying to get no-strings attached grants from places?

Hexapod conference? how to plan a conference budget?

caution: hexapods ahead. cc0

I applied to the deFlorez Fund for Humor at MIT. The application deadline for grants over $1000 was due at midnight, and at around 10pm I decided to apply for funds for a hexapod conference.

I should hear back by the end of MIT spring break (the 30th).

Funding decisions will be made approximately two weeks following the application deadline. If an award is made, disbursement of the award will take place once sufficient funds have been secured to hold the event.

 If they fund this, it will be hilariously awesome. However, the application is so hilariously rushed and badly written that I am actually really embarrassed. It was so much fun writing it though. The coherent parts were written by the lovely +Julia Hopkins (, including this beautiful part:

Please explain in one or two paragraphs how exactly this event fits the de Florez Humor Fund mission of “impressing students with the importance of humor in all aspects of life, both personal and business.”

Let’s face it. An MIT student’s personal life is their work life. Too few are prepared to find the humor in this, or prepared to acknowledge such humor exists. This conference epitomizes silliness in research, silliness in personal projects, and silliness in how we envision the technical world around us evolving. Moreover, it highlights the importance of this silliness in a student’s daily life. The concept of a hexapod, the concept of investing time and resources into something that, in the end, probably won’t change the world (unless you build it several stories tall and figure out how to give it a Godzilla complex), resonates with many an MIT student. This conference is to help them both acknowledge and celebrate all of the things in their research, classes, personal lives (for those that persist in imagining they have one, in any case), and business which have not gone the direction they anticipated, or which did not provide as much of an impactful result as they were envisioning.

I would try and explain the humor of wrapping all of this up in a metaphor of hexapods and then go on to wax eloquently (or perhaps just wax) about the philosophical implications of how a project which has gone nowhere can still impart necessary skills and life lessons, but that’d be spoiling the fun of it. You should come see for yourself the wonders of dancing hexapods, the hours of toil put into this utterly silly contraption, and experience your nervous laughter as this parody evolves into genuine humor acknowledging all of the ridiculous things humans do which, somehow, make the world a better place. We’re just not sure how yet.

Well, anyway.  How do you plan a conference?

Well, you decide on a mission (yes, conferences have missions) and then make a budget. This is a most excellent guide on missions and general conference thoughts:


 The field needs a conference.  There are several possible reasons for this:
  • The field may be a new one, and still lack a clear identity.  A conference could bring together the people who are building it, and help to define it.
  • The field may not be cohesive.  People in it may not know one another, may disagree on methods or other issues, or may simply not realize how many others have similar interests.  A conference could bring them together and create networks that would expand and improve the work.

The mission of this conference would be to promote silliness at MIT.

Here is the budget I ended up with:

Item Cost Comments
venue rental fee connections (held in the N52 IDC space, using equpiment there)
food and beverage fee 300 (can be acquired from dumpsters but kind of sketchy)
transportation & lodging scholarships 500 to help people make it here
A&V, recording, livecasting equipment 150
speaker fee bribe with cookies
activity fee 100 (lasercut hexapod material – bristol board)
miscellaneous fee 100
prizes from reuse
Total 1150

(budget table in neater formatting here)

And here is my (rambling because I had no time) proposal:

The conference schedule (tentatively planned for May 4th) would be

9 – 9:30 registration, breakfast
9:30 – 10 keynote speaker
10:15 – 11:15, break, 11:30 – 12 five-minute lightning talks (+ 5 minutes questions), nine total
12 – 13 eat food and make hexapods (invite general public, including kids)
13 – 14 hexapod dance-off, other hexapod competitions (e.g. fastest?)
14 – 17 conference talks about specific topics (e.g. the use of hexapods in educational kits, in adaptive terrain traversing (climbing trees, over rough ground), in millirobotics)
17 – 18 pm Poster session and demonstrations, appetizers

For reference, prior work:
An extracurricular undergraduate reading group I led last year.
The rapid fabrication hexapods we made during the last reading group session.

Hexapod Demonstration II from Katy Gero on Vimeo.

Khan Academy has hands on projects now / general web roundup
Hands-on projects at Khan Academy? So it begins.

In fact, there’s even a “lead of applied learning” position at Khan Academy (ran across this while browsing the SXSWEDU schedule)  who is “focused on leading and supporting a variety of strategic initiatives and creating project based learning content.
Vibrobots / brushbots: an alternative to using toothbrushes (and cutting up new ones or something) for a class is to use business cards! See howtoons: “Introducing Gami-Bots!“. Pretty awesome.

In other news, I am going to linkdump from facebook because it’s hard to search through facebook posts.

There’s actual less-derpy flying hexapods now:

Now they just need to write the code to make it dance… Also apparently going to be on kickstarter soon, like everyone else’s projects ever.

Additionally, there’s a simulation game for making robots covering things like drivetrain tradeoffs now/soon/in-the-making! Exciting.

I discovered pinterest, or rather pinterest for hexapods:

2009? How did I miss this? ^^

it actually walks!

That same term, lasercut mechanism, on google pops up a BS in MechE thesis by one of my classmates, @JoshRamos
It’s a paper about trying to make a lasercutter. Has good background information, so goes on my toread list.
According to +peter krogen on facebook,

Peter Krogen · mmm laser cutter made of legos Its a shame he didn’t build it in 2012, then he could have used the new 2w 445nm diodes (which have much better beam quality) that were available a few weeks after he turned in his report.

Additionally, discovered this on a list of startups at the ongoing San Francisco Hardware Meetups, a folding portable kayak:

origami kayak!

Finally, I am going to be addicted to this site, I just know it. There is now a robotics StackExchange site:

braindump: further research on online education and/or kits

general pedagogy’stheScience/Penick_Where’stheScience.pdf (restricted to class) (ugh, I hate that I can’t share this article, it’s an excellent one. It’s from 1991, sheesh).
The basic idea is, this teacher started out doing a cool demonstration in class, however, when students went to do it themselves, they did the bare minimum needed to replicate it without much enthusiasm. Then, the teacher switched it up — he asked students to predict the outcome of the experiment, and also structured the demonstration such that the students themselves came up with some of the lab procedures, like adding water to acid very slowly, that the teacher would then try. The students then were very engaged and eager to figure out whether the experiment would work out like they thought.

How global is online education?

Wow, it really is really all around the world. This is exciting to me. They’re really at a scale where they can have pocket communities form on google hangouts. The Media Lab Learning Creative Learning class, which actually has a tremendous following and is really cool.
(g+ community:

Gears, serving as models, carried many otherwise abstract ideas into my head. I clearly remember two examples from school math. I saw multiplication tables as gears […] I am sure that such assimilations helped to endow mathematics, for me, with a positive affective tone that can be traced back to my infantile experiences with cars.[…] First, I remember that no one told me to learn about differential gears. Second, I remember that there was feeling, love, as well as understanding in my relationship with gears. […] the “body knowledge,” the sensorimotor schemata […] It is this double relationship–both abstract and sensory–that gives the gear the power to carry powerful mathematics into the mind.

Wah, cool,
Crowdsourced video captioning and translation! This is excellent. I will often spend a long time typing up video transcripts just for my own reference, so cool to be able to not just have it for myself, and also a really convenient interface online. Now someone should just hook this up to those language learning programs online… ALSO. Why can’t I type things and the software automatically figure out where in the video it belongs? I think that is definitely a do-able thing.

I am particularly interested in session 2 (interest-based learning) and session 5 (open learning).
session 5 notes:

“how and when learn should be under control of learners” (well, maybe not below a certain maturity level) and “who participates” not limited
“we want to crack it open, what we’re learning, figure out how it works at fundamental level” “things that let us dive in and not just sit back and consume are incredible important” “also produce” “still hasn’t changed schools in which most learning still happens” “there is a strong notion of activism” “[teaching at university] I want to go, everyone gets an A today, if you still want to come back, great lets learn something”
(all of this conversation seems focused on university level)
are MOOCs example of what have in mind, do they fall short in some way?
do need to interrogate what mean by open (not slapping on a label)
letting anyone sign up for a class is huge, don’t want to diminish that at all
but do want to ask, is open enrollment sufficiently open?
never took a programming course, learned from being exposed to people way better than me
(me: i wish that were possible in the open source hardware community to the extent it is in the open source software community! how can we make that happen?)
idea of debugging ideas, all sorts of things in open learning,
often best way to learn, push yourself to maybe things start to break, 

toread: yay, pills. -.- This reading is flaming awesome. 

It is unlikely that sufficient resources will be available to build enough new campuses to meet the growing global demand for higher education  

Open Educational Resources (OER) movement 

Light discovered that one of the strongest determinants of students’ success in higher education— more important than the details of their instructors’ teaching styles—was their ability to form or participate in small study groups. Students who studied in groups, even only once a week, were more engaged in their studies, were better prepared for class, and learned significantly more than students who worked on their own. 

In a traditional Cartesian educational system, students may spend years learning about a subject; only after amassing sufficient (explicit) knowledge are they expected to start acquiring the (tacit) knowledge or practice of how to be an active practitioner/professional in a field 

 “productive inquiry”—that is, the process of seeking the knowledge when it is needed in order to carry out a particular situated task


The recorded audio is now online, and I’m guessing they won’t have recorded video

Online Learning
“US Department of Education
Evaluation of Evidence-Based Practices in Online Learning
A Meta-Analysis and Review of Online Learning Studies”

I listened to two talks, which you can find if you go to the “audio” site and look up the titles. Some notes:

  • Project Based Learning: The 8 Essential Elements
    mostly “hey supply chains are actually difficult” and the actual implementation of a donorschoose but hyperlocal supply granting program instituted in El Paso, Texas
  • MOOCs: Hype or Hope?
    this is a big mess, e-commerce took 10 years: amazon is there, but what was in-between, cosmos delivered candy bars in the middle of night, …
    this is the phase we’re in: people are going to try weird stuff, it’s not going to make any sense, but we’re trying, that transformation is happening.
    change: not only matriculated students, now global. MOOCs are changing the concept of matriculation.

some talks i picked out to listen to in the future:

sadly does not appear to be online 

Project Based Learning: The 8 Essential Elements

The Double Bottom Line for Education Entrepreneur
This panel will discuss social entrepreneurship in education and look at examples of education social ventures that have successfully scaled.

Tinker Tailor Solder Ply: Why Makers Rule in EDU
Hear how makers are helping kids unlock their creativity while applying their STEM know-hows — and, in doing so, shaping how we rethink the value and purpose of an education.

Nation in Decline: Why We Suck At Science & Math

Meet the Educational Stars of YouTube

Breaking the Mold: New Models for Learning (K-20)

The Magic of Making: Engaging Students As Makers
We’ll look at the importance of creating makerspaces in schools, developing a community of practice around engaging kids as makers, and how online tools can enhance and extend the value of making to the broader community.

Think Outside the School: Learning is Everywhere
 How can we use social technology to foster peer-learning and to recognize knowledge acquisition regardless of where it takes place?

Based on the case studies of the Mozilla Open Badge project and E-180,

Digital Harbor Foundation
will share our experience designing a Common Core aligned tech and maker curriculum that helps place kids in real world paid internships.

Peer-to-Peer Marketplaces, Meet EdTech
they also allow their educators to earn meaningful income by teaching online

Open Education: Still a Chasm to Cross

The Problem Finders: Design Thinking Across School
learn about new techniques for getting the best ideas, language use, and higher order thinking out of students.

Not Another Zombie Idea: Customizable, Open Digital Content Transforming Learning
 also the future of concept-based (bite-sized) learning leveraging multiple modalities (text, videos, exercises,interactive learning objects) that will help students and educators transform learning experiences.


Some thoughts on expectation management versus just getting courses up and out there:

“Given the prestigious name of the institution and their reputation for ground-breaking methods developed in the Media Lab, my expectation was that, as part of the transition to on-line delivery, they would have taken time to prepare a clear and thorough presentation of the subject, taking academic lectures to a whole new level.”
“I’m afraid the lectures have the feeling of “oh bugger, I forgot to prepare anything, I will do it as I go along”. You can get away with this in real lectures, but for video presentation then I’m afraid it isn’t good enough.” … “With all the resources of MIT, it must surely be possible for someone to digest these lectures and present them in the form of mostly pre-made slides

Developing Countries
One of the stories that was exciting to me about 6.002x was a university prof or student in another country who was like, hey, I will take this and make it an after-school program, because this topic isn’t really taught at my university (or something like that). I think MIT’s model of hands-on learning (mens et manus) is definitely gaining momentum (not MIT-driven, of course, but still). E.g. Skoltech, SUTD, and based on my own conversations with people such as +David Li, China’s government is interested in supporting makerspaces.

Is this actually true though?

Are universities good candidates for foreign aid? Blattman thinks so;

Foreign aid’s educational blind spot

Second, the aid community are on top of primary education like an overzealous mother. Tertiary education is pretty much ignored. The MDGs are both a cause and en effect of this sad state of affairs.

The United Nations is to focus more strongly on higher education in developing countries, Qian Tang, UNESCO’s newly-appointed Assistant Director-General for Education, said in Paris last week.

education designathon, liveblog (ish) – hands-on activity resources for teachers

look! it’s a woodie flowers, who as it turns out really dislikes massively open online courses (MOOCs).

chilling at the designathon
lots of cool people and ideas being thrown around (mmm… throwing people)
you can read all about prof. flower’s agenda against MOOCs in the tech & the faculty newsletter

kittens! from education arcade talk

people gave talks. 
e..g the educational arcade one, some notes:
why do goats and animals continue to play dangerous games that can end in death? play must be advantageous if this behavior wasn’t selected out by evolution/
4 freedoms of Play
freedom to experiment, freedom to fail, freedom to try on identities, freedom of effort (can play intensely or at a relaxed pace)
exact opposite of
4 freedoms of school

educational games are not “grand theft calculus,” tricking people to learn calculus by giving something the skin of a game

Then we did a lot of research into my recent problem of finding hands-on activities for primary school kids.
A teacher there mentioned, there lots of message boards where half the activity is teachers looking for a specific activity to fit a specific curriculum standard

This is my fourth year teaching but my first year at a new school. I am having a hard time trying to find labs for my students to do. I am in a regular room that is not made for a science class. I do not have bunsen burners or gas. I looked in the chemistry chemical cabinet and there are really not many chemicals.

Wah, this is cool way to not bother busy teachers, lurking on teacher forums 🙂

  • july and august: good times to get teachers to notice new things, when they take a break / do professional development workshops / reflect on their lessons
  • scale: must do it through professional societies (american association of physics teachers, etc.)
The Head of the MIT Department of Physics was also there and he is so awesome. He specifically said he is trying to figure out how to increase the numbers of people from underserved communities coming into STEM. %lt;3
Anyway, Turns out there’s an excellent site specifically for finding science and math hands-on activities, (perhaps more oriented at least for the lower grades), at

Our research notes here:

talking to teachers!
hi michelle

So, we decided the issue we were trying solve (collecting resources like how2today and observationsblog and connecting them to teachers) was approximately solved by (probably busy teachers want a fully-fleshed out lesson plan anyway), and we split up to work on different things.

I’m going to make a drawing robot and go ahead and throw together a demo online education with real-life kits thingamabob.

braindump, education (online, and IRL elementary school)

what are engineer (the design process is being taught in weston field elementary)

education designathon is tomorrow
woodie flowers will be speaking there! i still have like a hero worship thing going on from my FIRST robotics days.

once i dreamed of talking to woodie flowers about education and such
then i failed to grad school, or at least my super-specific version of grad school ^^; (MIT 2.007x)… eheh strategic failure
maybe it’s for the best, because i’m super excited for the future now! as opposed to stressed o__o
or maybe that is the soda talking
i wish them all the best, i hope it doesn’t turn out to be a lot of talk and indecision and less doing

oh also as i mentioned i am co-teaching lessons in a 4th grade science classroom
the teachers are super nice for letting us do this x.x
also learning a lot about pedagogy
the difference between doing a demonstration (e.g. a chemical reaction) and asking students to predict what will happen and then letting them do it (mystery novel! there’s suspense!)

1) hands-on online blah mouthtwister thing
to make this happen logistically:

  • live dirt-cheap (pika… ~$1.5k for three months. oh man, i can go there and eat all the portobello mushrooms! okay to be fair i just want to live at MITERS all the time but maybe that is okay, also there is a waitlist so if i don’t get in then my living costs go way up, oh dear)
  • affiliate self with shop: done (TAing job, again where being female was a plus… mixed feelings, but it should be super fun!)
  • earn money (contract work?, other places)
  • convince friend to come work on this near full-time with me, work out logistics (in progress)
    it’s a childhood friend who is a senior at cornell (she’s doing a M’Eng – PhD thing, so I only have her for the summer :3), and does meche and ee and bio things, i am super excited!
    plot twist: she is also super-awesome at piano and improv, which means by summer’s end i should be one step closer to my goal of being a hobo playing piano in bars in europe
  • feed ourselves during the summer ( accelerator program? only pays MIT students) 
  • ? get the word out ( peer-to-peer university)
  • read read read. 
    One of the big challenges of online learning is to scale the expert. In the studio model of learning, which is pretty much how things work at the Media Lab, more experienced students and faculty will review and critique your work. That is hard to move online. But we’ll try. As part of the course, we will organize a studio review session in which Mitch and Natalie will invite some of the online students to present and discuss their work and give them feedback.
  • … we didn’t build a shiny new platform. Our platform is the web and we like things distributed and open. We also wanted to create a model that is easy to replicate for anyone. We use off-the-shelf Google+ tools, like Hangouts and Google+ communities; and open source software like the Mechanical MOOC (github). You have no excuse not to build a course like this yourself!

Although initiatives by MIT, Harvard and other leading universities such as Coursera, Edx, Udacity are generating a lot of of buzz, I strongly believe it will be startups led by young students themselves rather than old brick-and-mortar colleges and universities that will be responsible for changing the way students learn.

From my own observation, universities running these programs are fundamentally limited, because their first priority must always be to the real-life students they are serving, and more often than you might think there are staffing issues in answering real-life students’ questions, let alone the questions of a gazillion people of varying backgrounds online. responsiveness — i don’t see that happening in a top-down fashion. perhaps as universities change? how do you motivate students to help other students? a stack-exchange-esque platform?

This is what I think: People are taking these courses because for many it is the only way to learn about interesting topics like robotics or machine learning. Take a video of a Stanford professor talking about a hot topic and people will eat that up. That does not necessarily mean that we have unlocked the power of online education. I also doubt it will give any value to a Stanford student who can sit in the real classroom.

2) elementary school projects
Wah! I get to teach this term as part of D-Lab Education at Weston Field School, which has a long history of working with the Kasiisi project / partnering with schools Kibale National Park in rural western Uganda. Thus, I’ve been doing a lot of research into hands-on projects for kids, which is more fun than I thought it would be. 
Holy hexapods, there was a sxsw conference about education:
That was this week. A ton of interest in hands-on learning on the schedule there. XD; SUCH A FAD. Well, looks like I need to wait a few days for the videos to be up.
oh, and briefly, i’m making a writeup on rapid-prototyping tools, so for my reference:

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.