By Brookelynn Morris
LED hula hoops are so beautiful to watch, and creating a custom hoop is a satisfying challenge. Twenty-one LEDs are used in this hoop; 6 are flashing LEDs that cycle through the colors of the rainbow. Each light is combined with a resistor and then wired together in a classic and simple parallel circuit.
Be sure to research each part and its specs when creating the circuit design. Each LED for this project was chosen for its similar voltage drop, making things simpler by requiring only one value of resistor.
The battery for this project can be a laptop battery like the one used here, or a few AAA batteries taped into series. Either way, the tube can be taken apart for the battery to be easily changed. Experimentation and thoughtful research will make this project successful.
Translucent plastic tubing, about 12′ I used HDPE plastic, 3/4″ outer diameter x 0.75 wall, “natural” color, product #58017 from http://www.usplastic.com. The tubing must be translucent so that light can be emitted from within, and HDPE’s natural color is a translucent milky white. It must be stiff, yet easy to bend in a circle. The diameter is an important consideration: ” tubing is less expensive but trickier to fit the circuit and battery into, while 1″ tubing costs more but gives more options for batteries and their holders. A common package length is 100′, enough for almost 10 hoops.
Barbed pipe fitting to match tubing diameter, from the plumbing or garden section of a hardware store
White electrical tape
Switch Almost any kind will do, so long as it fits into the hoop.
3.6V lithium CMOS battery with axial leads
LEDs (21) of any color, including multicolored flashers
22-gauge wire with white insulation
Stiff wire like an unbent coat hanger
PVC pipe cutter
Soldering iron and solder
Epoxy or hot glue (optional)
In the spirit of our “Teach Your Family to Solder” week, the flashback I’m offering up this week is from the pages of our sister publication, CRAFT. Brookelynn Morris’ LED Hula Hoop project from CRAFT Volume 06 is a super fun project to practice your mad soldering skillz. It’s fully suitable for peeps who have never soldered before and still fun for peeps who are pros. The best part is that you end up with a flashy toy that’ll make you the life of the block party. Here is a picture of Brookelynn’s friend Dawn in the throes of soldering up an LED Hula Hoop of her own:
In the project, Brookelynn even has a sidebar titled “Soldering Is So Easy”:
Solder virgins, never fear! Imagine a soldering iron as a conductive-metal glue gun. A glue gun uses heat to melt glue that is sticky and liquid, and cools quickly. The soldering iron is similar: it’s a heat element that melts the metal solder into small drops of hot liquid metal. Just press the tip of the iron against the wires to be soldered to heat them up for 2-3 seconds, then touch the solder right onto the connection and watch it melt, forming a liquid metal connection. Just as with a glue gun, after the melted material has been laid on, it quickly cools and hardens. Be sure to remove the iron and the solder while the drop is still hot, so they don’t stick to the connection. Apply the solder like a glue gun, but then brush it like paint: make a smoothing, rubbing motion with the tip.
Don’t be afraid to try this technique for the first time. The tools are available for $10, and as with anything new, practice makes perfect. Feel free to burn through a foot of solder making practice drops onto practice joined wires. It’s very satisfying to watch the metal melt and to see the perfect soldered connection.
For a great video soldering tutorial, visit makezine.com.
The Maker Shed also offers the ProdMod LED Hula Hoop Kit, which conveniently compiles all of the materials you need for this project for you. You bring the tools and the skills.