Fiber Optic Pleiades Star Map

The Pleiades, or the Seven Sisters, is a distinctive open star cluster with diverse significance in a variety of cultures. Inspired by other fiber optic star map projects seen here on Instructables (https://www.instructables.com/id/Star-Map/), I attempted to make my own small-scale star map of the Pleiades as a gift. Unlike many of the other star maps of this kind I have seen, I wanted the map to be as visually appealing unlit as it is lit, so I incorporated the illuminated stars into a printed background depicting a stylized, schematic view of the features of the Pleiades.

While I am very pleased with how the project ultimately turned out, the process involved a great deal of trial and error. In this instructable I will first give the optimized version of the process, then comment on the mistakes I made and how you can avoid them. Be aware that portions of this project are fairly tedious and time intensive, so give yourself plenty of time if you have a deadline to meet.

How it works:
The differing intensity of stars as seen from Earth is simulated in this star map by using three different diameters of light conductors. Clear acrylic rods essentially behave like giant fiber optics, or light pipes, and are used for the more prominent stars. Fiber optic is used for the smaller stars. Each light pipe is lit by its own LED and the fiber optics are lit by additional LEDs in the housing.

Using the optimized method, the following materials were used.

-Fiber optic (0.030" diameter, ~50ft)

-Extruded acrylic rod (0.125" diameter, ~6ft)

-Extruded acrylic rod (0.060" diameter, ~6ft)

-Foam board

-Shadow box frame (9"x9")

-Cool white LED fairy lights (DO NOT try to use full sized LED christmas lights, see "Mistakes to Avoid")

-Heat shrink tubing

-Adhesive (double sided tape, water-based superglue)

-Aluminum foil

-Tacks / nails

-Patience (lots)

Fiber Optic: http://www.amazon.com/Plastruct-FOP-30-Fibre-Optic...

Acrylic Rods: http://www.eplastics.com/extruded-plexiglass-acryl...

The first thing you will need to do is choose a design for your star map. I was able to find a finely detailed technical map (file attached) of the Pleiades and I used this as the basis for my background design. Some of the elements on the map were modified for the sake of aesthetics: The circle was centered, the title changed, gridlines removed, and nebula markings smoothed. Importantly, the stars were not included on the background. Be sure to account for the area of the background that will be covered by your frame. An additional version of the map with the stars was prepared to use as an overlay for making the stars. I used GIMP to design the background; .xcf and image files of both are included.

The background design was printed on heavy weight, high gloss paper by a local printing company; you can do this yourself if you have the right printer, however typical printers will probably not accommodate printing anything with dimensions greater than 8.5"x11". The overlay was printed on light card stock. I would highly recommend having multiple copies of the background and the overlay printed for practice and in case you make any mistakes.

The background was affixed to the foam board using double sided tape. This was first attempted with glue, but glue tended to ripple the paper whereas double sided tape allowed the background to be mounted perfectly flat. The overlay was placed over the background and held in place with masking tape.

As before, I would recommend making at least two of these; one to practice inserting fiber optics and light pipes and one as a final version.

I found that the most effective method for mounting fiber optics and light pipes was to first use the overlay to punch all the necessary holes in the background/foam board and then add the hardware after removing the overlay. Because I had 3 different diameters of fiber optic/light pipe, I colored the stars on the overlay based on whether a fiber optic, small, or large light pipe would be placed in that position. Note that since each light pipe will require its own LED, you should not have more light pipes in the map than LED lights, and the map will look better if you have plenty of LED lights remaining. I used 60 light pipes and string of lights with 100 LEDs. Depending on the star map you use you may not be able to illuminate all the stars, so choose the stars you want to depict before you start punching holes.

The holes should be as close to the diameter of the fiber optic/light pipe as possible and certainly not any larger. In order to makes holes of the correct diameter, you may need to improvise. I used a syringe needle for the fiber optic holes, a compass point for the small light pipe holes, and a sharpened screwdriver for the large light pipe holes. It is important that whatever tool you use to make the holes is as sharp as possible so as to not deform the surrounding foam board. If small tears occur in the background surrounding the holes, use a pigment pen to conceal the tear.

Once all the required holes have been made, insert the appropriate light pipe/fiber optic through each hole. The fiber optics/light pipes should be inserted through the front of the background to prevent tearing of the background. Trim fiber optics and light pipes such that ~5mm extend from the back of the foam board. Once all the fiber optics/light pipes are in place, ensure that the fiber optics/light pipes are flush with the background in the front and generously apply a strong, water-based glue to the base of each fiber optic/light pipe on the back of the foam board. Standard superglue may damage the fiber optics. Allow to dry overnight and cut the foam board to the final dimensions.

In the photos, the fiber optics are trimmed to a much longer length, see the "Mistakes to avoid" section for more information on why this is a bad idea. Additionally, you will notice that the light pipes are attached to large LEDs with heat shrink tubing. While this method ultimately proved disastrous, adding a short section of heat shrink to the end of the light pipes will make gluing the small LEDs much easier. For the small diameter light pipes, wrap tape around the end to allow the heat shrink to tightly cinch.

Place the background/foam board with the fiber optics an light pipes into the frame. Insert tacks or small nails into the inside of the frame (The shadowbox I purchased came with an internal frame to hold the contents in place). For each light pipe, bend the wires of LEDs and tape the wires the the back of the foam board such that the LED is positioned over the light pipe; apply glue once each LED is in position. Continue until each light pipe has a LED glued to it. Wrap the remaining LEDs between the nails/tacks inserted earlier so that the LEDs go across the as much of the area of the star map as possible; these LEDs will illuminate the fiber optics. The wires will hidden in the final product, so thankfully the appearance is unimportant (chances are it will look pretty ridiculous).

Affix a sheet of aluminum foil, with the reflective side of the foil facing out, to the inside of the back of frame using double sided tape. Cut a small notch at the bottom edge to allow the cord exit. The aluminum foil ensures that light is properly reflected rom the LEDs to the fiber optics. You may want to wrap the wire a couple of times around a nail or tack near the hole to prevent tugs on the cord from displacing any LEDs.

Once the glue has completely cured, plug it in and enjoy!

As noted previously, this project involved extensive trial and error. My initial idea was to use a full-sized string of LED christmas lights and to collect the fiber optic strands into bundles for illumination. The christmas lights proved to be much too large for this application and a lot of my work was destroyed trying to make them work. Also, I found that bundling the fiber optics was unnecessary. The light from the extra LEDs in the back of the frame is more than sufficient to light the fiber optics, and using short lengths of fiber optic reduces the required length of fiber optic needed by half or more. In summary, to minimize your blood pressure, the cost of the project, and the time it takes to complete observe the following:

-Do not use christmas lights

-Do not bundle fiber optics

-Measure how much of your background will be covered by the frame

-Practice mounting fiber optics and light pipes on a throwaway version

-Be conscious of the number of LEDs you have and the number of bright stars you want to include

Although I am very pleased with the final product, plenty of opportunities for improvement or variation remain. While mounting the paper background on foam board worked fairly well, it is not ideal. If the tools are available, using a plate of black acrylic for the background with a laser etched design and laser cut and/or drilled holes for light pipes/fiber optics would make for a vastly more robust background and could be finished much more cleanly. The potential variations on this project are nearly limitless as well. The star map could be made smaller or larger to accommodate different constellations or designs. Also, mixing cool white and warm white (or even colored) LED strands may make for interesting effects. Finally, the star map ended up being slightly too bright. In the future I may wire a potentiometer into the lights to allow for brightness control.

Thanks for reading!