Introduction: Fiber Optic LED Dandelion Lamp
There are those times when the world is so luminous and beautiful, times when you find yourself mesmerized by the huge sky filled with stars, or the infinite universe in little pods and thistles.
This ambient wall lamp is inspired by the beauty of nature and magic of light. It’s made with very common materials and simple tools. I wanted to make something that looks nice even when it’s not lit, and easy to change light bulbs also. This is my first time working with fiber optics, LEDs & circuits, it’s an experience of learning through doing, and there will be a lot of beginner’s discoveries shared here.
Step 1: Materials and Tools
This wall lamp is a half sphere composed of drinking straws and optical fibers, held together by a cardboard 'slices of orange' structure, and back-lit with different groups of color LEDs.
The following amount of materials will be enough to make a half sphere of 14” diameter. If you want to make a bigger sphere, consider that the surface area is calculated by the formula 4x3.14xRxR. Thus the amount of materials will increase proportionally.
• 300+ feet of 0.75mm end glow optical fibers: I ordered a sample pack of various sizes first. I find the 0.25mm too thin to work with, and the glow tips are really small. The 0.5mm and 0.75mm fibers are great for craft projects like this and star ceilings. When it gets to 1mm and up, the fibers get more rigid, although the glow tips gets bigger. This is the only material here that's not easily found in local stores. One way is to purchase it online from places like http://thefiberopticstore.com/, or buy 1 or 2 UFO lamps and cut the fibers off.
• 5mm LEDs in white, pink, & blue. (3) of each colors: I learned a lot about LEDs from this great instructable (thank you noahw!) https://www.instructables.com/id/LEDs-for-Beginners/ . A LED voltage varies by the color of the LED. Since these will be in a parallel circuit(more on it later) powered by (2) AA batteries , and they all happen to be 3.0v to 3.4v, there will be no need for resistors.
• Around (300) 9”drinking straws: I chose plastic straws because of their translucent quality. These happen to be bendable, but that’s not necessary.
• White card board, I used some ultra-rigid white mailers: this will be used to build the inner structure of the half sphere, and the enclosure of the circuit. White looks almost invisible behind the straws.
• (2) AA rechargeable or regular batteries, and a 2-AA battery holder wired in series: If you use a battery holder wired in parallel, it will still work here. The lights will be less bright.
• A SPST rocker switch : a simple on-off switch. SPST stands for ‘single pole, single throw’.
• 22 gauge hookup wire and pliers to strip the wires: 2 different colors make it easier to see the circuit
• Lead free solder and soldering iron: a really nice article here explaining lead free solder in detail- http://hackaday.com/2008/05/22/how-to-go-green-with-lead-free-solder/
• (4) 1” brass fasteners and (2) metal paper clips: I got inspired by this(thank you matt.e.jenkins!) https://www.instructables.com/id/Build-a-Simple-Circuit-from-a-Pizza-Box-No-Solder/ and decided to try it by adding a switch to play with colors of the LEDs
• Electrical tape
• 3’ of 12 lb-test monofilament fishing line: for building the inner structure & hanging the lamp. It looks identical to the optical fibers, so keep them apart to avoid confusion
• A mini glue gun and 3 sticks of all purpose hot glue
• Scissors, box cutter or exacto knife, circle templates or compass, some clips, velcro, some white tape
Step 2: A Structure Inspired by an Orange
I was thinking about different structures to hold the straws, and found my answer in a delicious orange, another good reason to take many snack breaks!
First draw 2 concentric circles onto the white cardboard, the inner circle is 3.5” diameter, and the outer one is 6” diameter. Draw a line through the center to mark the half points. Cut out the ring shape.
Make 3 of these rings, fold 2 of these along the center line, and align them at mid points. Like making a book, attach all 3 pieces along the center line by sewing with a needle and fishing line, so the middle pieces can be turned like book pages, and the bottom ring stays rigid and flat. Clips are helpful for holding things in place while you sew.
Select one end of the centerline and attach extra 1’ to 2’ length of fishing lines. Once the lamp is all finished, we’ll make a knot here to hang it on the wall.
Step 3: Make Modules of Straw and Optical Fibers
One of the most essential things in this step is choosing the right adhesive to use on plastic straws and optical fibers.
Plastic drinking straws are mostly made of polypropylene, which will not bond to many types of glues. Hot glue is one of the few exceptions.
I have read conflicting views on hot glue with fiber optics, so I did a test to see whether hot glue will craze the outside of the fiber and reduce the transfer of light. The photo here shows 2 pieces of fibers held up to a light source, one with a dab of hot glue applied, one without. The difference in light intensity is so minimal that I happily proceeded with hot glue.
Here’s how we make each module : snip the center of a straw with scissors, be sure to leave some still attached, and bend it into a ‘V’ shape. Cut the fibers into 5.5” to 6” long pieces, and put a fiber into each arm of the ‘V’, let the fibers stick out about 0.5" on each end, use a little hot glue to secure each fiber at the tip of the ‘V’. And that’s it!
Note: try not to let the tip of the glue gun get too close to the fiber, it will bend the fiber too much. Once you get a feel, it’s quite easy actually.
Step 4: Attaching ‘V’ Modules Onto Structure
You could make all the 300+ modules, then attach them. I find it’s nice to make a batch of 50-100, attach them to the structure, then proceed with the next batch.
The reason is that the straws come in 4 colors, and if you are using all 4 colors, you may prefer to use more of some and lees other colors. As your design is taking shape, it’s very helpful to step back often and look at the entire sphere, so the colors are nicely mixed and balanced. The closer it gets to finish, the more specific you’ll feel about how many more of each color straws you may need.
Align the straws along the rings, the bottom tip of the ‘V’ should end at the inner circle of the rings, and each straw should point to the center of the sphere. Put a dab of hot glue to one side of the ‘V’ and glue it to the cardboard. Let the other part of the ‘V’ dangle a little so the whole thing won’t look too monotonous when completed. It’s also helful to stand the ‘V’ on it’s side as we glue – see picture tags- because once the cardboard is full, we will be glueing more modules to the ‘V’ arms of existing ones.
Keep in mind that the middle section will take more straws, the ends less. – see photos
Steps 3&4 takes the most time and patience, once you filled all the noticeable gaps, you can hang the half-finished piece as a wall sculpture and admire its beauty!
Step 5: Design the Circuit
The diagram shows 3 of each color LEDs connected in parallel circuit to the power supply – batteries in this case, and switches. Because these 3 kinds of LEDs are all 3.0v-3.4v, and our power supply is 3.0v(2 AA batteries), we will not need resistors here. If you choose color LEDs that’s less than 3.0v with 3v power, you will need to connect them with the correct size resistors.
If you are a total beginner like me in electronics, here’s an explanation of series and parallel circuits, with some quotes from Wikipedia.
In a series circuit, components are connected along a single path, the current through each of the components is the same, and the voltage across the circuit is the sum of the voltages across each component. Every device must function for the circuit to be complete. One bulb burning out in a series circuit breaks the circuit.
In a parallel circuit, components are connected in parallel, the voltage across each of the components is the same, and the total current is the sum of the currents through each component. So a group of lights in parallel, each light has its own circuit, so all but one light could be burned out, and the last one will still function.
This gives us 2 good reasons to use parallel circuit here:
1. If a light burns out, we can see which one needs to be replaced.
2. All the 9 LEDs can be powered by 2 AA batteries, which adds up to 3.0v
I thought it would be fun to also have a switch that allows certain colors to light up, and this ultra cool instructable gave me something fun to try - https://www.instructables.com/id/Build-a-Simple-Circuit-from-a-Pizza-Box-No-Solder/
Initially I thought I would just flip the paper clip switch from white, to blue, to pink. Then it occurred to me that if the paper clip touched both blue and pink, we can have both color LEDs lit up. So I redesigned the switch to allow 7 color combos – white, pink, blue, white&pink, white&blue, pink&blue, white&pink&blue. See photos in the next step.
Who knew electronics can be so fun!
Step 6: Building the Circuit and Enclosure
Solder each components according to the circuit drawing. Wrap all exposed conductive parts with electrical tape.
Cut out a piece white cardboard same size than the ring pieces we used for the semi-sphere with a slightly bigger and flat bottom. I initially cut out the inner circle, and taped all the LEDs so they would just stick out to the bases of the fibers. See one of the photos. There are also photos showing how the 7 different color combos are achieved. See tags on photos.
After some tests, I realized it’s better to places them on a nice grid so the lights will distribute more precisely and evenly. So I made 9 holes for the LEDs on the inner circle to poke through, and taped it back to the rest of the enclosure.
The bottom part of the enclosure is flat. The idea is to have the switches accessible yet hidden from front view.
To create the 'Color Switch' (not sure what an electronic name for it should be) with a no-solder method, insert 1 brass fastener through the cardboard base next to the main rocker switch, wrap one end of the stripped wire around the base on the inside of the enclosure, the part where the 2 pins are should be outside the enclosure. Hook 2 paper clips onto the pins and spread the pins to secure. Next, use the paper clips to measure where the blue, pink, and white buttons should be. Wrap the negative end of each bundle of wires to the corresponding fastener. Spread the pins to secure the wires, make sure no conductive parts of these 3 fasteners are touching. tape each end with electrical tape to keep them separate. See photos of both sides of the cardboard for better understanding.
Use Velcro to attach the battery holder, and tape down all the wires after the LEDs are in place.
The sides of the enclosure is made with a long strip of 1” wide white cardboard and hot glue, to give rigidity and to ensure the lamp hangs flat on the wall.
Use Velcro to attach the back side of the half sphere of straws, to the front face of the enclosure. Make sure the LEDs are centered on the inner circle where all the optical fibers ends are sticking out of the straws.
In the future when we want to change lights or modify the circuit, simply detach the 2 parts and there’s no worry if the pretty part would be damaged.
Step 7: Time to Celebrate
The most rewarding part of this journey is that I finally stepped from drooling over other members' LED creations to actually designing and making one! If you are like me who loves the glow of LED but feels like an alien to electronics, just try start with something small. Once the first bulb lights up, you'll fall in love with electronics!
After a long journey, now it’s time to hang the lamp, enjoy all the lights and colors flowing out of the straws and fibers, and dream about galaxies!