Introduction: Galaxy Mobile
I have seen a lot of 2D galaxy art on the internet, such as galaxy shoes, t-shirts, wallpaper, etc but I haven't seen any 3d renderings. In this Instructable I have attempted to make a 3D galaxy in the form of a hanging mobile. Since I haven't figured out how to create a black hole (yet), I resorted to using Christmas lights, fibre optic filaments and some polyester batting. The mobile has one large galaxy, which sort of looks like the Milky Way and four smaller more distant galaxies.
Step 1: What You Will Need
- Fibre optic filaments (I got mine from a dollar store toy)
- Polyester batting (or wadding if you are from the UK), cotton balls or wool roving
-I chose to use the batting because it was a bright white colour, as opposed to a more yellow white of the roving or cotton balls
- CD -actually it is a clear plastic disc protector that you get when you buy a multipack of DVD or CD disks, it is usually at the top of the stack of discs
- Organza fabric (you can sometimes find rolls of this at a dollar store, if not go to a fabric store)
- Drinking straw
- Twist tie
- Glue -I used a spray glue, super glue and a glue gun
- Coloured glitter glue sticks for the glue gun
- Key ring, and duct tape
- (Optional) hair dryer/ hot air gun and small circular metal tin
Step 2: Prepare Background
To begin, I cut several, (6 actually) pieces of organza roughly the same size as the CD. I used the CD as a template to cut the fabric. Once cut I glued 3 pieces of fabric to either side of the CD using a spray glue (the circles are applied unevenly to give it a more airy cloud like appearance). I then cut a hole through the fabric at the centre.
Step 3: Prepare LEDs
My lights has ten LEDS, I arranged them so that there were 2 at the end, a bundle of 6 and 2 near the battery pack. I tied the bundle together with a twist tie. The bundle is stuck through the hole in the CD, with the 2 LEDs near the end fed through the hole as well. When you hold it up from the battery pack, you wnt he CD to hang at an angle ( roughly 45 degrees), add some tape to the wire coming out the back so it does.
Step 4: Prepare Fibre Optic Filaments
I had used fibre optic filaments in a previous instructable to make a bracelet that lights up. In that Instructable I distressed some of the filaments so that there would be some points of light along the length of the filaments rather then just at the ends. Please refer to that instructable for instructions on how I did this.
The next step was to divide up the bundles into two parts roughly the same diameter as the LED. I used a drinking straw that was wide enough to fit around the LED and fibre optic bundles, from which I cut two pieces about an inch long. I inserted the fibre optic bundle into one end of the straw halfway in (we need to leave room for the LED at the other end) and glued it with a clear drying glue.
Since I will need the fibre optic filaments to curve in the shape of a spiral, I pre-curled them to hold the shape better. (This only works with plastic filaments not the glass ones). I placed the bundles into a small circular metal container and heated it with a blow dryer for several minutes, be careful not to overheat it, the ends may warp.
Step 5: Attach the Fibre Optic Filaments
The next step is to attach the fibre optic filament bundles to the LEDs. I selected two LEDs coming out of the centre of the CD and inserted them into the end of the straw, and glued it together with a clear drying glue. It is important that the fibre optic bundle sits flush against the LED to maximize the transmission of light.
I then divided each of the bundles of fibre optic filaments into smaller bunches (off shoots of the galaxy's spiral arms). I taped the filament into bunches with clear tape. I then curved the bunches around the surface of the CD gluing them in place with hot glue to form the spiral arms (I used an image of the Milky Way as a rough guide).
With a pair of scissors I trimmed the ends of the fibre optic filaments so that they don't extend too for past the edge of the CD and the ends are tapered. Test it out with the LED lights on, you want the points of light to be spread out rather than all in a bunch.
Step 6: Add Fluff
In this step we will add the batting over the fiber optic filaments to give the galaxy an airy feel of dust and gas. Since the four lights in the centre of the CD are really bright, I placed a dense wad of batting over them. I then continued to add more tufts of batting following the curves of the fibre optic filaments. I glued the batting directly to the filaments and to the organza in some places with a glue gun (don't glue the batting to batting, it gets too messy). I varied the density of the batting between the spiral arms and their offshoots as well as thinning it out at the ends. Add the batting to the backside too, although the galaxy sits at an angle, you can still see the backside, plus if you use a clear disc instead of a CD light will pass through the back as well. I tried to have the spiral arms at the back line up with those at the front.
Step 7: Add Colour
To add colour to my galaxy I dyed some of the batting to shades of purple and blue. For the blue I used a Rit dye and dyed it as you would a wool roving. (I haven't tried will Kool Aid, since it is hard to find blue Kool Aid in Canada -but it could work too). Since polyester does not take up the dye as well, I left it in the dye much longer and did not rinse after, I just pulled it out and let it dry on paper towel. For the purples, since I didn't need very much, I used a Sharpie. I just grabbed a tuft of batting and coloured it.
As I mentioned in the previous step, it is best not to glue the batting to the batting since it gets messy. What I did was to use a felting needle and teased the coloured tufts together with the batting already on. This didn't require much effort, there seems to be static or something that attracts the batting to itself (possibly the gravitational pull from the centre of the galaxy).
I used the coloured batting to accentuate the shape of the spiral arms, adding darker blue along the edges and towards the ends. I then ran a vein of purple along the centre of each of the arms. I left the centre of the galaxy plain white. Also remember to do the same to the back.
Step 8: Distant Galaxies
For my mobile I wanted one large galaxy and several smaller distant galaxies, that is why I arranged the lights so that I have 4 free lights, two above and two below the large galaxy. To form these galaxies I used coloured, glitter hot glue sticks. I held the light with an alligator clip (so that I don't burn my fingers) and coated the LED with the glue. I waited for it to cool before adding another layer, so layer by layer I formed the shape. To create arms, I placed a drop of glue on the edge and used gravity to pull it downward. Once it had completely hardened you can trim it with scissors to refine the shape. I did this for each of the four lights using different colours.
Warning: it is really easy to burn your fingers doing this, make sure you have something other than you fingers to hold the light while your working on it.
Step 9: Hang Your Mobile
The mobile itself does not weigh very much (perhaps it is because of the dark matter). The battery pack is the heaviest part of the mobile so I attached the hanger directly onto it. My hanger consists of a key ring and another connecting piece that can rotate (I also got this part from a key chain). I used duct tape to secure the key ring to the battery pack. Like I said, the galaxies are not very heavy so that you don't have to worry about straining the wires of the Christmas lights.
Step 10: Additional Thoughts...
- There is definitely room for improvement, the most obvious problem is that the on/off switch is on the battery pack, so if you hang the mobile from the ceiling you will need to stand on a chair to turn it on. One way around this is if you use remote control operated lights. I believe you can get remote control Christmas lights, there are also LED strip lights that can be controlled by remote.
- Another option to turn the lights on/off is to incorporate a LDR into the circuit, so when it gets dark out, the lights on the mobile turn on. Fortuntely there are plenty of Instructables that show you how to use an LDR in a circuit.
- When I was taking photos of my galaxy, I noticed how lonely it is on its own. A nice starfield background would be a great accompaniment. For some of my photos I just poked holes into a piece of cardboard and shined a light through it, it works but it is only a short term solution. I would recommend a star projector , a fibre optic starfield or even glow in the dark sticker that you can add to your ceiling and wall.
- Since I used the Christmas lights I was limited to how many LEDs I had and how they were arrayed. Had I made my own circuit, I could adjust the spacing between the smaller galaxies (I thought that the two closest to the large galaxy were too close) as well as arraying them horizontally vs vertically which is what I initially hoped to do. Likewise, had I made my own circuit it would be easier to incorporate an LDR. My reasoning behind using the Christmas lights was that it would be accessible to more people. Though if you plan to make one and own a soldering iron I encourage you to wire up your own lights, it would give you more creative control!
I had some other points that I wanted to add here but I can't remember them at the moment. If you have any comments or suggestions I would be happy to hear what you think!