Customer project 74 - Star ceiling disk
We were interested to receive this detailed report from our customer Bob P in January (2013) since his format coincides broadly with a new prefabricated system which we were preparing to launch. We're aware that not everyone is desperately keen to spend a lot of time crawling around on joists in the attic, so we have been developing prefabricated alternatives to allow customers to buy ready-made star ceilings.
One of the new range is a 1200mm disk, which is very similar to the size which Bob settled on for his project, although we're using a much lighter panel than the 25mm MDF on which Bob based his disk.
List of major components
- Custom 370 fibre harness and MH 570/1 light source fitted with a blue and white twinkle wheel.
- 1 sheet 2440mm x 1220 mm x 25mm MDF.
- 1 circular piece of 9mm ply @ 855mm dia.
- Tin of Blackboard paint.
- 1 Sky template printed at A0 size giving a diameter of 825mm.
- Tube of black Silicone sealant.
- 4 off 12 Volt light units, associated cabling and transformer.
- Assorted drills to suit fibre diameters
|Bob's disk features an MDF rim with an inner circle made from plywood.|
To add depth and interest to his disk, Bob decided to place his circular star field within an outer ring, which was made from 25mm MDF with I/D of 825mm and O/D of 1210mm. This was then rebated on the internal diameter and a circle of 9mm plywood set into centre of the fitting flush with the upper surface. This gives a defined centre circle where the fibres were fitted to form the 360° view of the night sky
The top (hidden) surface of the disk, prior to adding the fibres. The circular disk of plywood is rebated into the thicker MDF ring to create a flat surface, and another ring was added to the rim to create a gap between the fibred area of the disk and the ceiling.
Bob had decided that he wanted to model the actual night sky, inspired by the spectacle of a particular night. "This particular time (at 20:50hrs on 22nd March 2012) was chosen because that night we were travelling South on the A1 from Harrogate and the eye was drawn to the brilliant show put on in the South West by Venus and Jupiter."
Venus and Jupiter are the brightest objects in the sky, other than the sun and moon, easily outshining even the brightest of stars, so the conjunction of the two made a dramatic sight.
|The disk was given two coats of blackboard paint, and four holes cut to accommodate 12 volt halogen downlights.|
To allow himself to accurately model the brightness of the stars Bob asked us to make up a custom fibre harness in a mixture of 1.5mm, 1mm and 0.75mm diameters. He created another lesser level of brightness by recessing some of the 0.75mm fibre ends so as to reduce their output.
|Bob used a star chart as his template for positioning the stars and also to determine which size of fibre should be used for each star so as to model the relative magnitudes of the stars and planets.|
|The custom harness comprised 370 mixed diameter fibres, all at 2.5 metres.|
"The final result is fantastic viewing in the dark looking up to the fitting, which no photograph or video can reproduce," says Bob, although he hasn't done a bad job here. Fibre optics are notoriously hard to photograph.