After seeing harddrive POV display projects like Ian Smiths, I decided to give it a try and make my own using a broken harddrive and an Arduino controller.

Process:

1. Driving the motors: I first tried to find out how a brushless DC motor operates by probing the signal with a oscilloscope. It turned out they are more complicated to start up and control than I anticipated. Therefore I decided to use the built-in controller instead of designing my own.
2. Detecting the motor speed: I used a transmissive photomicrosensor, which consists of an infrared sender and receiver to detect a slot cut into the bottom platter of the harddrive.
   
3. I used surface mount RGB LEDs, which are convenient due to their small size:
   
4. To install the sensor and LEDs, holes were cut into the back of the hdd and the components glued in place with cables leading to the control circuit. Then the original motor control circuit was screwed back on to hold the cables in place and to run the motor:
   
5. This image shows a test of all LED’s turned on (red) with the upper platter not installed. The red circle highlights the location of the sensor. The white tape is at the location of the slot in the upper platter, so the LED’s are more visible:
   
6. The sensor input is analyzed by the Arduino microcontroller to determine the drive speed. The microcontroller then flashes the LEDs to display graphics. The following image shows the Arduino control circuit on a breadboard:
   
7. A slot cut into the spinning upper platter of the harddisk is used in conjunction with the flashing LEDs to display graphics on the device.
   
8. A video of the display showing a rainbow test pattern can be viewed here: http://www.youtube.com/watch?v=bNkj0Uc-hnU

Components:

• 3.5 inch harddrive
• PC power supply with 5 and 12V output
• Arduino Mini 3 with mini USB adapter
• Photomicrosensor: EE-SX1103 (Transmissive)
• 6 pc Full Color PLCC4 LED: OVSARGB3R8 (OPTEK Technologies)
• 3 pc MOSFET: 2N7000 N-Channel 60-V (D-S)
• Resistors: 6*470 Ohm; 12*240 Ohm; 1*330 Ohm; 1*50 Ohm

This is the first material the composite is based on Magne-View by Magnerite. (http://www.magnerite.com)

The second material is phosphorescent green by Golden Acrylics. I wanted to keep the Magne-View in mint condition, so I painted the phosphorescent color onto a clear sheet.

I thought the paint might be transparent enough for the Magne-View to come through, which turned out to be a wrong assumption:

Luckily, the green sheet is not completely opaque. Therefore, I tried to go the other way round and have the phosphorescent material shine through the Magne-View.

Here are strips of phosphorescent tape pasted to a sheet:

The flashlight reveals their glowing capabilities.

Final result: The phosphorescent material shines through the Magne-View, but only in very dark rooms (hence no photo of that). It would be interesting to add phosphorescent material to the Magne-View in the production stage, but I would have to investigate that further. Interesting and promising stuff nonetheless.

Assignment questions:

a. Does your composite support new and unique applications?
The composite could be used to increase the quality of 2D vision based motion tracking systems on surfaces. Due to the resulting visual patterns, the output of the material could also be used for artistic installations.

b. Can you design an interaction scenario around its ‘responsiveness’?
When a user draws on the surface with a magnet or a light pen, the material changes it’s visual characteristics. The visuals stay on the surface for a given time (phosphorescent material) or until a new stimuli is applied (magnetic film). This visual “trail” left on the surface can be utilized to increase the tracking quality when sensing input with a magnet or light on the surface with a camera.

c. How is it different from other technologies?
It is different from other camera based tracking methods, as the surface helps to increase the camera tracking quality, but has no active component.
The passive technology is used to support camera-based sensing with good results even when the tracking frame rate is low. The surface consumes no power.

d. Would it be possible to mass-produce it? How?
Use CES to learn about different fabrication processes.
I did not find the Materials used in the CES databank. However, as they are all commercially available, they could possibly be mass-produced:
- Magne-View ® Film: micro-encapsulated film
- Golden Acrylics: Phosphorescent Green paint
- Pro Tapes and Specialities Fluorescent Yellow Artist Tape
I would have to investigate the production process of Magne-View further to find out why it is green and if it can be mixed with other colors like the phosphorescent paint.

Assignment for MAS 962: Techniques for Design and Fabrication. Thanks to Adam Kumpf for the idea of using the Magne-View surface for tracking and for lending the materials.

Collection of the National Gallery

It is apparently hard to automate the manufacturing process of carbon fiber objects. That’s bad for business but good for the craft community. According to make magazine, it’s not all too complicated to make a custom carbon fiber case (http://makezine.com/09/primer), so lets try that. They made a case for an iPod, which involved making a mold, sanding and cutting. I am too lazy for that and therefore tried a simplified version for my external harddisk instead (plus I don’t have an iPod).

As noted before, making a nice cast is currently not an option, so I just cover the case in wax paper instead.

Then I cut the sheet of carbon fiber down to a convenient size to cover the harddisk nicely.

Time for mixing the epoxy. Due to a lack of tools, I can’t mix the exact amount of resin with hardener and eyeball the mixing ratio instead. Not very smart and should not be replicated. At this stage, the project is turning into an open ended experiment.

The epoxy gets pretty warm inside the cup, thus melting it. Not good.

I mix another batch of epoxy in another cup. Unfortunately, only a few drops of epoxy are left for the case now, barely enough to nicely put the thing together. Also not so good.

Anyways, although the epoxy was not mixed properly, it hardens. You can see a still live of case and harddisk below.

The closeup reveals some structural problems with the case, which can be attributed to a lack of epoxy, knowledge, dedication and preparation.

Anyways, carbon fiber is good fun and makes me want to repeat this experiment! (With more epoxy, knowledge, dedication and preparation.)

http://www.instructables.com/id/USB_cellphone_charger_cable

The staircase I propose has displays built into the steps, which are wirelessly connected to the web and have a sensor network. The stair senses where the people on it currently are and displays appropriate content to inform and entertain them. The information complexity displayed on the stair depends on the number of people walking up and down. If many people are walking on the stair or walk very fast, only simple, basic information like the weather forecast is displayed.

If the staircase senses a single user with more time, it can also display more complex information.

Games are also possible. In this one, the person walking up the stair should try to avoid the foes.

A little instructable explains how I created it: http://www.instructables.com/id/Sockophones_earphone_padding_made_from_socks/

According to the labels, the laptop components were assembled in the following countries:
* China: frame, case and keyboard, modem
* Taiwan: graphics card circuit, mainboard, CPU heatsink, touchpad, network card, buttons
* Korea: IC’s on mainboard and graphics card, RAM, DVD drive and case
* Japan: battery, speakers

After putting it back together, I discovered that no screws were leftover. Very strange, usually I always end up with a few spare parts. At least the machine shows the same nice effects on the screen as before.

If you are interested in laptop supply chains, check out Leonardo Bonnani’s website: Unraveling the Reach of Product Design