This year for Halloween, my son wanted to be a wizard. To go with his wizard costume, I made him a flashlight in the shape of a magic wand. To make it even cooler, I designed the wand so that it is turned on with a magnetic reed switch built into the handle. That way when my son picks up the wand with a magnet hidden inside his glove or on a ring, the light will magically turn on. But when anyone else picks up the wand, it won't do anything. I had a lot of fun making this project and my son had a blast playing with it.
Step 1: Watch the Video
Here is a video walk-through of the project.
Step 2: Materials
Here are the materials and tools that you will need to complete this project.
LED Flashlight (less than 2 watts)
Magnetic Reed Switch
Ball Point Pen
Large Paperclip (or other steel wire)
Hot Glue Gun
Blow Dryer or Hot Air Gun
Step 3: Take Apart the Flashlight
The first thing that you need to do is take apart the flashlight. The exact way that you do this will depend on the specific flashlight that you have. But it will usually involve unscrewing covers, removing screws, prying open snaps, popping glue seams or any combination of those. Just keep taking it apart until you get down to the LED and its connectors.
Step 4: Remove the LED
Next you need to remove the LED. In most cases this means that you will have to desoldering from a circuit board. So heat up your soldering iron. Melt the solder on one of the leads of the LED. Then carefully pry the LED up off the board. It is easiest to do this with the help of a small screwdriver. Melt the solder on the other lead and remove the LED from the board.
Step 5: Mark the Polarity of the LED
Next you need to mark the polarity of the LED to help you keep track of which side is the cathode (negative lead) and which side is the anode (positive lead). The easiest way to do this is to take a battery pack (with the same voltage as the flashlight) and just touch output wires to the leads of the LED. If it lights up, then you know that you have the right polarity. To mark this, I just took a sharpie and drew a big black line on the negative side (the cathode).
Step 6: Trim the Housing of the Magnetic Reed Switch
In order to assemble the wand, the magnetic reed switch and its housing need to be about the same size as the AAA batteries. The magnetic reed switch that I used had a large plastic mounting tab on one side. So I carefully cut it off with a knife. I also rounded off the corners a little.
Step 7: Cut and Strip One of the Wires of the Reed Switch
For this design, I needed one of the wires to be long and one of the wires to be short. The short wire will connect to the bottom of the stack of batteries and the longer wire will connect to the LED at the top of the stack of batteries. So I used a pair of wire strippers to cut and strip one of the wires so that it is slightly longer than the housing of the reed switch.
Step 8: Connect the Reed Switch to One of the Batteries
Take the exposed section of the short wire and curl it into a loop. Then using a piece of electrical tape, tape it down tightly onto the negative end of one of the AAA batteries.
Step 9: Tape All the Batteries and the Reed Switch Together
We want all the batteries and the reed switch to be taped together into a long cylinder. So cut off a few short pieces of electrical tape. Then tape the batteries together positive to negative. Stretch out the tape as you apply it so that they two batteries will be pulled tightly together. Put one strip of tape on each side of the batteries. Then tape the reed switch onto the bottom battery.
When you are done, you need to test the battery pack to make sure that you have made good connections. You can do this by putting a magnet up to the reed switch, and then using a multimeter to measure the voltage of the stack of batteries. Alternatively, you can also test it by connecting one lead of the LED to the top of the first battery and the other lead to wire from the reed switch.
Step 10: Attach a Second Wire to the Top of the Battery Pack
Take a second piece of wire and strip the insulation off the ends. Curl one end into a loop and place it on the top end of the battery pack. Use another piece of electrical tape to tape it onto the end of the battery. Stretch the tape as you apply it so that it makes a tight connection.
Step 11: Place the Battery Pack Inside a Plastic Straw (optional)
To help keep the batteries and the reed switch lined up, I put them inside a plastic straw. Just take a regular plastic drinking straw cut a slit down one side with a sharp knife. Then wrap it around the batteries and the reed switch.
Step 12: Add the Barrel of a Ball Point Pen to Make the Cylinder Longer
I decided that I want to the make the wand a little longer. So I added the barrel of a ball point pen as a spacer. Just take a plain ball point pen and remove the back clip, the ink cartridge and the front tip. This should leave you with just the barrel. If you want to make the barrel smaller, you can take a pair of sharp scissors and carefully cut off part of the barrel.
Fit the barrel into the end of the straw in line with the batteries.
Step 13: Wrap Everything in Electrical Tape
Take one long piece of electrical tape and apply it all along the full length of the cylinder. Make sure that the wires sit flat against the side of the batteries as you are applying the tape. Then repeat that on the opposite side. Lastly, wrap the tape tightly around everything from one end to the other.
Step 14: Glue the LED in Place
The LED needs to be attached to the end of the wand. The easiest way to do this is with hot glue. Apply a large drop of hot glue to the end of the pen barrel. Then press the LED onto the end. Allow this to cool. Then apply more hot glue around the edges.
Step 15: Connect the Wires to the LED
Once the LED is in place, you are ready to attach the wires. Line up the two wire with the appropriate leads of the LED. Wrap the exposed part of the wire around the leads. Then use a pair of pliers to bend the leads down onto the sides of the wand. This will help to hold them in place.
When you are done, test the light by putting a magnet up to the reed switch. If the light turns on, then you probably have good connections. If the light doesn't turn on, then one of your connections is bad and you need to fix it.
Step 16: Apply Hot Glue Over the Connections
Next apply hot glue over the connections that you just made. This will help to keep them in place and to insulate them.
Step 17: Apply Hot Glue All Over the Wand
There are a lot of ways that you can shape the appearance of the wand. Some people use Sculpey. Other people use Sugru. You an even use a wood paste made from saw dust and glue. But I decided to use hot glue. I chose hot glue because it is easy to work and rework. It also has the added bonus of making the wand water proof.
So heat up your hot glue gun and apply hot glue all over the wand. It may take a couple of glue sticks to get good coverage.
Step 18: Shape the Wand
Now it is time to shape the wand. The best way to do this with the combination of a blow dryer and the hot glue gun. Prop up your blow dryer so that it sits a couple of inches off of the table. Make sure that its intake fans are not obstructed. Plug in your hot glue gun and let it heat up.
Start with end where the LED is mounted. Hold this end a few inches away from the mouth of the blow dryer. Then turn on the blow dryer. The hot glue will gradually warm up. Turn the wand to make sure that both sides are heated evenly. When the surface of the glue becomes shiny, it is starting to melt. Now take the hot glue gun and use the hot tip to smooth out the glue on the wand. Try to shape the glue into an even coating all around the wand. Do this for the full length of the wand. Then let it cool.
Once you have an even coating all around the wand, you can sculpt it into its final shape. Again, start with the end where the LED is mounted. This time use the tip of the hot glue gun to brush the excess hot glue toward the other end. This is where we will shape the handle. You want the LED end to have a very thin coat and you want the handle end to have a very thick coat. Continue moving the hot glue toward the handle end until this end is noticeably thicker. Now use the tip of the hot glue gun to shape the handle into any design that you like. Depending on your design, you may need to add more hot glue in this area during the final shaping process.
Step 19: Apply a Base Coat of Paint
The last thing that we need to do is paint the wand. I did this in two coats. First I applied a base coat of gray. You want to use a thick acrylic paint for this. The color doesn't particularly matter for this coat.
Step 20: Apply a Second Coat of Paint
After the first coat of paint is dry, you are ready to apply the top coat. Again you want to use a thick acrylic paint for this. I wanted my wand to look like wood, so I used a brown paint. I didn't try to get 100% coverage with this coat because little bit of the gray showing helps to make it look like wood grain.
Step 21: Test the Wand
The wand part of the project is finished. To test it, hold your magnet up to the handle of the wand. When the magnet gets in range of the reed switch, the light should turn on.
Step 22: Conceal the Magnet in Your Hand
In order for the flashlight to work, it needs to be close to the magnet. But it is much more impressive if no one knows that the magnet is there. That way it looks like magic. There are two really easy ways that you can do this.
The first way is to conceal the magnet inside a glove. You can attach the magnet to the inside palm of the glove with either hot glue or by sewing it. The method that you want to use really depends on what kind of glove you have.
The second method is to attach the magnet to a ring. If you have a steel ring, you can just stick the magnet to it. If you don't have a steel ring, you can make a simple one from steel wire (such as a large paperclip) or you can just hot glue the magnet to any ring that you like.
Step 23: Use Your Magic Wand Flashlight
Now when you pick of the wand and hold the handle next to the magnet, the wand will light up light magic. To properly test out the wand, I gave it to my son to use with his wizard costume for Halloween.
Step 24: Safety Note
With the first wand that I made, I used a 3 watt LED. After being on constantly for about 10 minutes, the LED got hot enough to begin melting the hot glue near the LED. To avoid this, I recommend using an LED rated for 2 watts or less. Also you should not keep the light on constantly for long periods of time.