First version, too ambitious?

Ok, so the first version I did was maybe a little bit too ambitious…

Here’s some of the specifications of the first version of the table:

• Endlighten XL 8mm acrylic 1100mmx850mm
• 196 Osram SFH485P IR-leds
• A PS3-Eye cam from PeauProductions with a 850nm band pass filter

LED Frame Creation

I started with cutting an L-shaped aluminum profile into a frame with the right dimensions for the Endlighten acrylic and then drilled 5mm holes for all 196 IR-leds. After that I painted them black matte and mounted them onto a MDF board with a large rectangular opening for the projection and camera.

Next up was to solder all 196 LEDs which was a 7-hour job without breaks (follow my advice and take some breaks. My eyes got pretty blurry and I had quite some headache after inhaling soldering fumes for 7 hours…) The LEDs was connected in groups of seven with a 15Ohm 0.5W resistor in each group and there was a total of 28 groups in the frame. This means that the power supply has to be a 12 volt supply that can output at least 2.8 amps.

When the soldering work was finished I could start testing if I could see any blobs and I got blobs when I touched (or pressed) the acrylic without a diffuser layer. But that’s beacuse of the FTIR effect in the acrylic. So when I started testing the DSI effect with several types of diffusers (drafting paper, Röhm Evonik 99561 Rear Projection acrylic, etc.) I got no blobs at all. After some discussions at NUIGroup I concluded that my Endlighten sheet probably was too large and the IR-leds to weak to get a good DSI effect.

So now I’ve ordered a new bright 850nm IR-ribbon from Environmentallights and a new 850nm band pass filter from Peau Productions.

Stay tuned for more updates!