How To Make Almost Anything Class
Lassiter's WEEK #4 Assignment
This week the assigment was to go into detailed research on our final project.
Determined that I would need an actuator of some sort to move/telescope the heart layers out and in
from their resting place. First considered stepper motors, but realized that a lot of gears would be
needed and gears (at least the ones I would make) wouldn't move quickly enough to acheive what I
envision. Also probably need a pretty big stepper motor.Next I thought about pneumatic tubes--
but they are long, and it would make my device awkward to wear. Plus I'd need to carry a small
tank of air everywhere with me. Not a great solution. Neil suggested that I help Patrik make a
linear motor from a copper coil, a magnet and a spring. This sounds just right and I have consulted
Patrik on the matter. His response:
"The basic principle of what you mentioned is very simple:
1) There is a permanent magnet, say South, which can move back and forth along
an axis.
2) A spring, which pulls, is attached to the left side of this magnet.
3) On the right side, and not attached to the magnet, is a coil/
solenoid that,
when a current goes through it, creates a magnetic field that is North, so it
will attract the permanent magnet.
So, the spring pulls the permanent magnet towards the left, and the solenoid
pull it towards the right if a current goes through it. The more current, the
more the magnet will go right, the less current, the more to the left.
By regulating the current, we can regilate how far left/ right our magent is.
This is one way of making a simple electrically controllable linear actuator.
Of course we can change the game by putting in a spring that pushes, and
polarizing the solenoid South, so it will repell the magnet, and so on.
Patrik"
In addition, I started thinking about the sensor for determining if someone is within range, in order
stimulate the heart beat, and the closer proximity required for a faster heartbeat. I admit I was a
bit stumped, and figured I'd have to start from scratch-- using a small sensor board designed in Fab
class. Realized I would need a very expensive sensor and a big power source for this kind of approach.
Again, Neil suggested that I use the GPS tracking technology that the Norwegians developed last
January while in Boston. They used sonar transmitters and receivers and designed surface mount
circuit boards for this purpose. So I will try to reconfigure their design for my project.
Am thinking about the telescoping device, and can't quite visualize it yet. I want the hearts at rest
to have a flat surface, so anything I design has to be pressfit into the back of the heart layer.
I am still convinced that I want to use metal for the heart and have red blinking lights on the inside
with a red transparent cloth lining to diffuse the light while the heart beats.