This is the first of a series of blogs I intend to write about the development of light objects in the build up of my exhibition at Craft ACT (Canberra, Australia). For this exhibition I hope to have up to ten new designs developed. This show will open in early February 2009 under the title Highlights.
I just finished the first of these objects which takes advantage of new generations of high bright LED lights. The object shown here uses two 3 Watt warm white LEDs, waterjet cut stainless steel, rapid prototyped parts (in yellow) and carbon fiber tubes. Height 1035 mm.
The design is torch like with the intention to appear clear and slender. All elements are as thin as possible but strong as necessary. The tension of the bowed carbon tubes holds the lights in place while at the same time supply the electricity to the LEDs.
The main challenges with this piece was to source the right driver for the LEDs to achieve good brightness while maintaining a long lifespan. I used two Cree XR 3 Watt (Jaycar electronics no: ZD-0444) together with a driver (AA-0585) which automatically detects how many LEDs are there, 1-6 are possible on one of these drivers, this allows for a wide range of designs. The driver itself is connected to a 12 VDC 1 Amp power pack.
The electricity is picked up by the LEDs from the carbon-fiber tubes, the bowing of the a result of the ‘light fittings’ are wedged in place by pushing out the tubes. More then two could be fitted to this lamb (the driver would adjust automatically). The black round disk in the center of the yellow fitting in the image above is the LED’s heat-sink. Despite being very power efficient and producing ‘cool’ light these LEDs get hot on the back and need to have a heat sink to make sure they stay within their recommended working temperature 50 – 70 degree c. The shade is, for the moment, made from drafting paper.
The foot part holds the driver, switch and connections to the carbon tubes. I designed all yellow parts on a CAD program (form•Z) and then rapid prototyped on a Stratasys FDM machine in ABS plastic. I polished the stainless steel after it had been waterjet cut.