21 led's inside a 3/4 inch pipe for faster hooping styles.
Note: I did not make these instructions. Throughout the text it says, "I", this refers to the person that wrote this. I pulled the article from instructables.com
Step 1: Supplies
Here is a list of supplies you will need. All my prices are in Canadian funds. You can get things a little cheaper from ebay and such. But this was all bought from local
plumbing and electronics stores.
The hardest thing to find is a good tubing product. I wanted to use something that was fairly cheap, came in short lengths and had the proper strength and transparency i needed. The product i found that works best is Aqua-pex. It has writing on it with the brand and specs.. but it won't be noticeable at night , when you will be using a LED hula hoop anyway.
Supplies List
21 LEDS - $12.00
132" of 3/4" pipe - $20.00 for 20 ft.
1 x 3/4" pex coupler - $1.00
2 x 3/4" pex clamps - $0.50
36' x 22 ga Wire - $15.00 for 100 ft.
4 x AA NIMH rechargeable batteries - $18.00
1 x 6 volt battery charger - $15.00
1 x 1.75 x 4.75mm plug and dc Jack - $4.50
21 resistors - $2.00 for 100
1 x Slide Switch SPST on-off $$9.00 for 10
Everything comes to around $70
Plus a few basic tools you may already have.
Tools List
Soldering Iron, Drill, Solder, file or sandpaper, Flux, Electrical tape, marker, glue, pipe cutter, String, Wire strippers, Bubble wrap, and a paper clip.
Step 2: LED and Resistor Information
Resistors are basically used to drop the voltage so you don't fry the LED or draw more power then it needs.
Each LED requires a different voltage to light up. Some 2.4volts, some 3.6volts and so on.
Using OHM's Law, i calculated that with 4.8 Volts (4 x AA Rechargeable's). I needed 68 ohm resistors for the 3.6 V led's and 150 ohm resistors for the 2.4 and under
LED's.
Some people use exactly 3.6 volts, lithium or 3 AA batteries. But as soon as the batteries start dieing, they lose voltage and some LED's won't light up as bright or at all.
Use this tool to calculate which resistors you need for your LED's
LED Resistor CalculatorLED Resistor Calculator
Soldering the resistor is very easy. You can put the resistor on either the negative or the positive. It doesn't matter. I used the positive. Usually on a LED, the positive is
the longer of the 2 leads. I cut my positive leads before soldering, to make the length of each almost the same after i solder the resistor.
Step 3: Soldering Batteries
So I started the process by soldering all my batteries together in series. Basically negative terminal goes to the positive on the next battery. I wanted to evenly distribute
the weight around the hoop so I separated the batteries by 31-36" of wire, so i had some extra to play with. I created a little video to show you how easy soldering a
battery is. . WARNING! Soldering batteries is very dangerous and they could explode. Try at your own risk.
Video
Soldering Batteries.
Prepping the batteries. I have used many different kinds of batteries. This time i am using Venom 2400 mah batteries. I start off by charging them. Then I take my cheap
nail file and scratch up the tops and bottoms. Just so the solder has something to grab onto.
Since my hoop is 132 inches, batteries are 2 inches long and i need 4 of them. I need to have etleast 31 of wire in between each battery. So i made it 32 inches just to be safe.
Strip each end of the wire.
Put some FLUX on the battery end and the end of the wire. It acts as a bonding agent for the solder and makes soldering so much easier.Put a big glob of solder on
the soldering iron. Touch your wire to the battery and push the soldering iron on top. It shouldn't need to be help on there for more than 5 seconds. Remove the iron, and
blow on the solder. It should harden and you will be able to pick the battery up with just the wire. If it falls off try again.