Minggu, November 22, 2009

G-Meter and Altimeter


G-Meter and Altimeter
Double-duty aerospace instrument on a shoestring budget
David Simpson | Make Vol. 16- 2008 | Pdf | 4 pgs | 2 mb
Here's an aerospace instrument you can build for
$5 that will measure the crushing forces that a
model rocket withstands and the rarified strata it
attains. It isn't exactly six-sigma technology in
terms of accuracy, but it's darn fun.

The device, which you install in the rocket's
payload compartment, uses 2 small bands of
heat-shrink tubing that slide over a dowel to record
the maximum G-force and altitude attained. As
the rocket accelerates, the G-force band is pushed
down by washers on a spring, and as the rocket
rises, the altitude band is pushed down the rod by
the expansion of a pressure chamber made from a
pill bottle and a rubber-balloon membrane.
...

Jumat, November 20, 2009

Chladni Plate


Chladni Plate
Edwin Wise | Make Vol. 16- 2008 | Pdf | 11 pgs | 3 mb
BEATIFUL ACOUSTICS
Use a broken speaker, bits of wire, and
tape to prepare a coneless voice coil
driver, then use it to generate standing
waves on a sheet of metal, making
sound visible. Magic!

My knowledgeable friend Robin once
said that you don't need to worry about
having too big an audio amplifier,
because speakers are usually damaged
by under-powered amps working too hard
and clipping the signal, creating rough
square waves with too much power.
I learned that this is true when I melted
a speaker's coil by running a strong
20Hz signal through it, to drive a vortex
cannon (MAKE, Volume 15, page 114).

On the bright side, I now had a nice
speaker magnet to use as the foundation
for something else I wanted to try,
a Chladni plate!
...

DIY-brary


DIY-brary
Rick and Megan Prelinger couldn't find a library
with what they wanted, so they made their own
R.U. Sirius | Make Vol. 16- 2008 | Pdf | pgs | mb
It's an overcast Monday afternoon as I arrive at
8th and Folsom in San Francisco's seedy, bohe-
mian SOMA district. I find 3018th Street and then
buzz Room 215. A voice says hello. I tell him who
I am and he buzzes me in. I take an elevator to the
second floor, walk past several closed offices, and
enter a small room packed to the rafters with four
rows of shelves filled with books stacked 15 feet
high. This is not your typical 21st-century urbane.
haute-culture library.

The Prelinger Library (prelingerlibrary.org) is
the brainchild of Megan Shaw Prelinger and Rick
Prelinger. Founded in 2004, it's a DIY, appropriation-
friendly, intuitive, and highly personalized context for
organizing and sharing this couple's books, periodi-
cals, printed ephemera (like obscure government
documents from the Department of Indian Affairs),
and - most of all - their obsessions. In addition to
its physical presence in San Francisco. it has an on-
line presence of more than 3.000 scanned volumes
at the Internet Archive (archive.org).
...

Wheelchair Safety System


Wheelchair Safety System
Bryant Underwood | Make Vol. 16- 2008 | Pdf | 1 pgs | .4 mb
My daughter Katy uses an electric wheelchair
and last year she went off to college. Her mom and
I were concerned about Katy's safety in navigating
the campus -- she might get her chair stuck or have
some other type of trouble and not be able to get to
her cellphone.

So I used a Parallax microcontroller to control
a GSM cellphone as a "telematics" system for her
wheelchair. Inside the gray box mounted on the
back of her chair. I use the phone in speakerphone
mode with an external microphone and speaker.
...

Kamis, November 19, 2009

Malam Pertamaku



malam ini malam pertama buat aku
pertama kali membuktikan bahwa
engkau bukanlah SCAM
meski cuma sekian
bahagia rasanya hati ini
rasa penasaran
tuntas sudah

malam ini
malam pembuktian bagimu
untukku
NEOBUX

terimakasih TUHAN
terimakasih untukmu... NEOBUX
salut untukmu... NEOBUX
juga buat ALERTPAY... thanks

semoga masih ada
malam-malam berikutnya
seperti malam ini

ah, asyiknya...
dua kali dapat
BUX!