Sunday, March 17, 2013

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 http://www.mcmaster.com/#stepper-motors/=lwy84g

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
so
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
http://www.seeedstudio.com/depot/preorder-crazyflie-nano-quadcopter-kit-6dof-with-crazyradio-bccfk01a-p-1364.html?cPath=170_172
(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:
http://www.instructables.com/id/PCB-Quadrotor-Brushless/ by scolton
hi shane
hi charles

start-lolling
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:
http://medweb.mit.edu/healthplans/student/after_graduation.html
"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.
(http://www.city-data.com/forum/massachusetts/541525-how-much-do-you-pay-health-3.html).