STEP 1: Gather Materials
2x Clear 5mm LEDs - Color of your choice. White is what you'll probably pick.
2x 5mm LED Holder - Chrome or plastic.
2x 100 Ohm resistors
1x 2 AA battery holder - You could go AAA is you want.
1x button or toggle switch
1x Altoids Tin - Flavor of your choice.
Hot Glue Gun (Melt glue)
Optional & Helpful:
Total Cost: Less than $5.
You can pick up these parts most anywhere. Radio Shack has them, but you'll pay a lot for them. You can always use sites like All Electronics or Electronics Goldmine for a wealth of parts. I also sell the parts for these as well as pre-made kits on my website Brown Dog Gadgets.
STEP 2: LED Holder
Depending on how fancy you want to make your flashlight you may choose to use either a Chrome LED Holder or a Plastic LED Holder. They both work the same way and you really need to use one. This is the main aesthetic problem with most Altoids Flashlights, and the holders make all the difference.
In this guide I'll be using Chrome Holders, but plastic work just the same way.
Once you have your holders grab your drill bits. Find one that is as close to the size of your LED Holder as possible. Line it up in the back of your holder, as thats the part you're actually sticking into the tin.
Always err on the small side. You can always drill a larger hole, but you can never drill a smaller hole.
Step 3: Prepare Your Tin
Drilling an Altoids tin takes a bit of practice and patience. If you have an extra tin around (or if you screw up badly) do some practice holes. Get a feel for the pressure and force you need BEFORE you destroy the tin you're working.
Grab your drill and whatever drill bit you've chosen.
Before drilling choose the spots you want to drill first, and mark them with a marker. Otherwise you'll end up with holes that are off centered or all over the place.
Hold the drill in your dominate hand. The tin in your non-dominate hand. Have the tin on a table for leverage.
Now press the drill bit into the mark you made on the tin. Just a bit of a press to make a very small indent.
Now lightly press as you start drilling. Let the drill bit do the work for you. If you press hard against the tin you will mangle it.
Do that for each of the LED spots and the button spot.
BEFORE YOU GO ON put the holders and switch in the holes. If for nothing else to make sure they fit. If they don't fit you'll need a bigger drill bit, or use a file, or use a Dremel.
At this time you can also put some electrical tape down under the LED holders and switch. This helps insulate the tin so you don't end up with any shorts later on.
STEP 4: Prepare the LEDs
While we're only using two in this project you can easily use more or LEDs of different colors.
***If you're using Chrome LEDs you'll need to put the LED legs through the little plastic or rubber "holder" that comes with it BEFORE you do any soldering. If you forget this you have to start everything over again.***
Grab your LEDs. You'll see two legs. The short leg is Negative and the long leg is Positive.
Bend the short Negative leg upwards on both LEDs. This helps us remember that the leg is negative, and we need it up for later.
Now grab your resistors. Wrap a resistor to each of the long Positive legs of your LED.
(If you want to be super awesome with wire twisting, follow the photos.)
Then wrap the other ends of the resistors together. You should now have a Y shape.
STEP 5: Stripe the Battery Holder
Take your AA battery holder. Cut the wires about half way. (A lot of people leave the black Negative wire uncut. It honestly doesn't matter if you do or not.)
Strip both wires that are still attached.
Then take the Red Wire and twist it together with the back end of the resistors. (The bottom leg of the Y you made.)
You've not actually made nearly a completely circuit. If you wanted you could put in some batteries and then touch the black wire to the short LED leg and the LED should light up. Its always a good idea to test along the way.
STEP 6: Soldering
Soldering can be scary for the first time user. Don't fret though, it's something that is within your grasp.
When soldering you want to keep a couple things in mind.
1) Never touch the solder directly to the iron.
2) You want to heat up both wires.
3) Its the heat from the wires that will melt the solder.
If both wires are not hot enough the solder won't grip properly. It takes some practice, but it's a skill that even middle school kids can learn.
Take the soldering iron in your dominate hand. The solder in your other hand.
Put the tip of the iron against the place where you want to solder. In this case, the area you twisted the LED and Resistor together.
Once you're touching the iron to the metal, count to five. Now touch the end of the solder to a nearby spot on the wire. If it doesn't melt, just count to five again. (If it's not melting you might not be touching the soldering iron to the wire enough.)
Solder will flow around both of the wires. Once you've got a bit of solder remove both the iron and the solder. Let it cool for a moment and inspect it. It should be cool to the touch within 30 seconds.
Do this to both LEDs and to where the battery pack connects to the resistors.
Use a wire cutter to snip off any extra bits of LED or resistor that is poking out.
STEP 7: Hooking Up the Switch
If doing this project with a group of kids, it's best to wire everything OUTSIDE the tin before putting them in. This way they have more room to work, and if something does go wrong it's easy to replace a part.
(I actually have the kids in my class make the entire circuit on a table before we even solder. It depends on your group of kids and their skill levels.)
As an adult I like to start putting things in the tin at this point. More specifically the LEDs.
Pop the LEDs into the holders so that the Negative leg (which should be sticking at a right angle) is pointed straight up.
Angle the two Negative legs so they're pointing at each other, and give them a small twist. If you can only connect a small amount that's perfectly fine. A little twist is all we'll need.
Take the small scrap of wire you cut off the battery holder (or any other wire you have around) and strip it on both ends.
Wrap one end around the two Negative LED legs. It doesn't have to be perfect, it just needs to hold.
Take the other end and hook it up to one leg of your Switch. Take the Negativeend of the Battery Pack (black wire) and hook it up to the other leg of yourSwitch. The best way to do this is to thread it through the hole in the leg of yourSwitch.
Solder. Just be quick when doing your switch as most likely parts of it are plastic, and plastic melts. A quick five count and then put your solder on. Don't be afraid to back off and try again.
*** Toggle Switches ***
If you're using a toggle switch like I have in my pictures you may have three legs. You must use the middle leg. After that it doesn't matter in this project. It also doesn't matter which wire you put where, as long as one wire is connected to the middle.
STEP 8: Enjoy
Pop the battery pack into place, and throw in some batteries and you're done. Well I guess you could throw some hot glue all over it if you're super paranoid about short circuits, but as long as you've properly use electrical tape (translation: used insane amounts like me) you should be fine.
You now have a fully functional flashlight.
I highly recommend this project for all starting DIY people. It works for both kids and adults. It gives you a practical gadget that you can actually use or give as a gift to someone. Or, push come to shove, start your own little online business with.
The coolest part about this is that after you get the basics down you can honestly start doing insane variation on it. Multiple switches and toggles controlling different colored LEDs. Make it solar powered. Make it blink. You're a smart person and you have limitless options out there. Try some.
I hope this write up was helpful. If you'd like to see some more of my designs or kits, go and check out my website BrownDogGadgets.com. Most of the stuff on there has been tested out with the kids in my middle school science classes.
Here is a PDF with more pictures on how to make this Altoids Flashlight: Make-an-Altoids-Flashlight.pdf