This log involves the design and construction of a canvas print of the Aurora Australis mounted on a pine frame. Fibre optic lights will be placed at most star points and will have a flickering or twinkling effect like normal stars. The electronics will be mounted hidden in the back of the frame.

I had planned on using a bright and diffused LED light in the back of the canvas print which would have the effect of punching out the vibrant colours against the darkness. The effect turned out to be nearly invisible during bright daylight however during evening time the vibrant colours showed nicely.

I abandoned the LED light idea in favour of twinkling stars however; due the light from the powerful led inside the canvas creates this effect once the hard light has been diffused. As you can see from the photo the setup is such that the light between the bulb and the rotating disk cannot be diffused and at first the hard light from this created a highly visible cone from the front. Spray painting the back of the canvas black and blocking with cardboard fixed the problem. In hindsight i should have created the cavity for the switch and power insert in the frame before constructing it and painting the entire back of the canvas black before mounting would have been better. The area of canvas under the wooden part of the frame could not be painted after it was mounted and in darker conditions the ambient glow is visible in this area.

OVERVIEW:

The electronics mounted in the back will be a simple light shining onto a coloured rotating disk before entering the optic fibres. The optic fibres will be poked through the canvas at the star points. As the colour wheel rotates it will change the colour of the light specs and have the effect of flickering (hopefully). An alternative is a flickering candle LED light that does the same job only does not change colours like a real star on the horizon. The method i am using involves having an unsightly power chord hanging down the back of the frame but it means a can get a stronger power output and wont have to worry about changing batteries when they run flat.

PARTS REQUIRED:

• A suitable canvas print
• Synchronous Motor 12V 2W 50/60Hz (slow moving)
• LED bulb and ceramic mount 12V 5W
• Transparent Coloured Disk and stem
• Power switch
• Power insert
• Fibre Optic strands
• Power supply
• Second frame for shadow box
• Black spray paint
• MDF Backing board

You can extract all of these parts from one of those rotating flashing UFO lamps.

METHOD:

In this version i built the canvas print before anything else. In hind sight i should have drilled holes in the frame to hold the power switch and lead insert and painted the entire back of the canvas black before mounting but ya live and ya learn hey? So i had to start with a completed canvas with a thin frame which would present a problem later. The electronics i chose have a large footprint and i will need to build a semi shadow box on the back of the frame to extend its depth.

For example purposes i used a thicker frame to sit the electronics in position as you can see from the picture. Ultimately the power switch and power insert plug will be recessed into the wooden frame and accessible from the front to turn on and off. After completing the circuit and testing the electronics it is time to add the backing to the frame.