Let's Make Robots!

Edge lit zodiac display.

The school I work for runs extra Summer School classes over the summer break here in Japan and all the teachers are given some certain amount of freedom in how they teach the curriculum. Everyone is encouraged to make displays, signs, games etc. Basically let your inner child out and make some cool stuff :)

Part of what I have to teach is the western zodiac. The section in the kids textbook was really lame and everyone knows LEDs make things 100x better so this is what I have come up with... the LED-edge-lit-zodiac-star-sign-display!!

Heres the basic plan:

  • 2 layer clear acrylic.
  • blue stars on 1 layer
  • green or red line connections on the 2nd layer.
  • printed space background with sun and earth like the picture linked below.
  • optional: folding cover.
  • optional: pulsating "sun" LED in the middle.

I picked up some 2mm clear acrylic A4 sheet and transferred the constellations from this picture onto some tracing paper which I then lay over the acrylic. 10 minutes with a 1mm drill bit later and I had lots of holes! They don`t go all the way through (except for 2 mistakes). The plastic edges were sanded dry and then wet, then I tried flaming it with a jet lighter. The finish isn`t great but it will do.

Some 5mm foam board makes the base and sides for the first layer. A 5mm deep groove is cut into the foam board to accept the acrylic and lined with aluminium sticky tape to reflect the light back in when it hits the edge. The right side of the display will house the electronics and LEDs. 3 very bright blue SMD LEDs are wired up and hot glued on the foam edge.


Ignore the micros and the reflection of my hands.

Each LED is drawing 30mA which is a bit high and needs changing, but it looks brilliant when turned on, I was really blown away. Once the 2nd layer with the connecting lines is done I will see which order looks best.

I still have to reprint the space backdrop because it`s too small (/facepalm) duck up the road to get the 2nd sheet of acrylic, and find some different colour LEDs small and bright enough to work.

Until it`s finished you guys don`t get to see it switched on :p