Intro: Very Bright Lumos Wand for ~$10
This is a tutorial on how to make a wand capable of the Lumos charm from the Harry Potter universe for about $10. It is so bright you can use it as a flashlight!
The key to this design is a high power LED. I'm not talking about those little through-hole guys that you can use for underlighting your car... I'm talking about the 3 Watt LED's that they put in high powered flashlights! So this Halloween, I chose to put one of these buggers to good use. This project requires that you know how to solder.
Here's what you'll need:
- 1 3W LED - $4 at Digikey (Anything with the same voltage rating will work)
- 1 stick or piece of doweling cut 10 to 14 inches long
- 1 Energizer Lithium Photo 123 Battery (3 volts, available at most drug stores)
- 1 small switch
- 2 yards of thin, insulated wire (I used thin speaker wire for this tutorial, but unobtrusive two-stranded wire works great too.)
- Soldering iron and solder
Step 1: Cut and Wrap the Stick
I found that using a stick from an apple tree in my backyard. The twisted branch worked great to add a slightly more organic feel to the wand.
Trim any extra twigs off the branch and cut the business end (the end which will have the light) perfectly flat. This will be the spot where the LED will go, so you want it to sit well.
Once the stick is prepared, wrap two wires around its entire length. (In one version, I cross-hatched them. Using an amber colored wire, they added a nice pattern to the overall product.) Once you have the wires in place, strip them to expose the conductor.
Idea: For a really authentic look without visible wires, you can split your wand down its length, cut out a channel on each side, run the wire inside and glue the pieces back together. You could even steam and bend the wood when you're done to get that knobbly look.
You should now have two wires ending with an inch or so of slack at each end of the wand.
Step 2: Add the LED
This bit is a little tricky and requires soldering.
With the ends stripped from your wire, wrap the two contacts of the LED, securing it firmly to the tip of the wand. (It may help to use some hot glue to hold the LED there.)
Cover the wrapping points with a bead of solder to secure the connections. Don't touch the LED for too long with the iron or you could burn it out. (5 seconds is a good limit)
Once finished, secure the wires at the end somehow. A bead of hot glue under the LED is really effective.
Note: If you choose to use a higher voltage battery, heat-sinking may be necessary with the LED. I'm not using all 3 Watts. (Doing so will rapidly overheat the LED. Read the datasheet for the part before modifying.)
Step 3: Attach a Switch
This works the same way as the LED. Solder your wires to whatever type of switch or button you want. I recommend a momentary push button switch or something else that is relatively small.
I placed the button right where my thumb would be, this placement is up to you. Further back with a switch allows you to hide the electronics entirely in your palm. To secure the button, use a dab of hot glue.
Step 4: Connect the Battery
IMPORTANT! You must test that the battery is in the correct polarity before gluing it down! Otherwise, your wand will not light and you'll need to tear it apart!
Figure out how you want the battery to be placed. I put it as part of the base, so my hand covers it during use. Very sneaky. If you can figure a better way let me know! Maybe build a handle?
As stated above, you MUST have the battery placed in the right orientation or else the LED will not light up. Just test it before you solder mmkay?
First, insert the appropriate wire into the positive end's vent hole and twist it. This keeps the soldering to a minimum. Next, secure the battery to the rod with a small line of hot glue. Finally, take the negative wire and bend it so it touches the negative terminal of the battery.
NOTE: I soldered this. If you can figure out a better way, do that. Soldering on a battery is a risky business unless you are very quick. If you choose to solder this, do so in less than 1 second or you could cause your battery to overheat and explode. Know what you're doing, wear safety glasses and work in an open area, etc, etc.
Once you get a solid connection, tack the connection with a blob of hot glue to make sure it stays connected. This is probably the weakest point of your wand, so make sure it is well protected.
Step 5: Lumos!
Assuming you connected everything right, you should be able to key the button or switch and have your light come on! The Dragon LED I recommended has 180 degree output, making the wand a pinprick of light from all directions save that of the user. I have had people say that this wand looks exactly like the Lumos charm performed in the Harry Potter movies.
If I did my math right, using an Energizer Lithium Photo 123 3V cell, you should have about 17 hours of full power, magically blinding operation from your new wand. After that, the brightness will start to diminish, but should last you a very long time.
I used this wand to play Draco Malfoy on Halloween with a wizard's robe made from DIYFashon .