Film Canister Flashlight




About: The name Cat’s Science Club comes from my daughter Aly, whom I call Aly Cat. She inspired me to take my love of science, and the fun I have with my students, to as many people as I can. Both my daughters hel...

This film canister flashlight was more fun to build then an Altoids flashlight and feels so much more comfortable in our hands. Don't get us wrong, the Altoids tins are great. We just love the handiness of this little guy and no metal shavings when you drill into it!. We had it out by the pool as a nice affect, hanging in the basement where we needed extra light, by Cool Cat's bed as a night light, Ally Cat took it to school to hang in her locker, and of course we all use it as a flashlight.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Materials

3 Volt Battery (not pictured)
1 to 3 Magnets (depends on your method)
2 Wires (of different color and about five inches long)
Electrical Tape
Film Canister
Hot Glue
LED Holder
Toggle Switch (not pictured)
Wire Cutters

Step 2: Magnets

The first magnet is to hold the flashlight up on magnetic surfaces.

Place a bead of glue into the bottom of the film canister and add your magnet. This will need to be a fairly strong magnet to hold the canister up. We found 1 inch ceramic magnets worked well and did not cost to much.

Step 3: Battery Holder Option 1

We tried two different ways to hold the battery to the wires.  This is the first way but uses two more magnets.

Make sure that the magnets will attract each other and not repel. We suggest marking the magnets.

Expose a large amount of wire, nearly 1 1/2 inches, on each of your wires.

Wrap your wire through the magnet or around the magnet if yours does not have holes in it. Do this for both wires.

Check the polarity of the magnets to make sure they will be able to be attracted to each other and the magnet in the bottom of the film canister.

Place your 3 volt battery between your two wired up magnets. Take note of which wire was touching the positive side and which wire was touching the negative side of the battery. In our pictures we used black for negative and gray for positive.

Glue the magnets into place by gluing the the top, bottom, and a side of your "battery holder".

Step 4: Battery Holder Option 2

Much easier but not as much fun.

Strip the wires leaving about 1/4 inch of wire exposed.

Place the wire on to 3 volt coin battery. Using the electrical tape, tape the wires on to opposite ends of the battery. Make a note of which wire is on the negative end and which wire is on the positive end. In our pictures we have black as negative and gray as positive.

Step 5: Cut and Splice

Cut the negative wire in half.

Splice the wires connected to the battery at both ends of the extra black (negative) wire.

Step 6: Prepare the Toggle Switch

I was a bit worried about soldering but there are great instructables to help you learn how. I got a crash course from Fat Cat and it was not that bad. So here are pictures of my first ever soldering job.

Take the negative wire that is connected to the "battery holder" and wrap it around the outside prong of the toggle switch. Solder the wire to the switch.

Take the extra negative wire (our black wire) and connect that to the center prong on the switch. Solder it on.

Now your switch is ready!

Step 7: Connecting the LED

Most LEDs that we have found have the longer leg as positive. We bent the negative leg (the shorter) up so that we could easily see the difference.

Take the negative wire (black) that is connected to the toggle switch and wrap it around the negative leg of the LED. Solder in place.

Take the positive wire (grey) that is connected to the "battery holder" and wrap that around the positive end of the LED. Solder.

Does the light turn on? No? Try the switch ;-)

Step 8: Prepare the Canister

Drill a hole just slightly larger then the toggle switch switch into the side of the film canister. We found it easier with the lid on. We also liked the hole being in the upper 1/4 of the canister (close to the lid). It felt more natural in the hand.

Drill another hole into the lid of the canister. It was easier to have the lid on the canister while drilling. This hole is for the LED holder. We found that it was a good idea to punch a hole into the lid with a nail and then drill. The drill bit needs to be the right size for the LED holder. Better to start a bit smaller and work your way to a bigger hole until the holder fits.

Insert LED holder into lid.

Step 9: Put Together

Slide switch through the side hole and tighten screws.

Push LED into LED holder.

Hot glue (we actually use a low temp. glue gun) the exposed wires but do not glue to the side of the canister or you may not be able to close the lid. Wires will stick out.

Snap on lid after glue dries.

Step 10: Light It Up!

Turn your film canister flashlight on and try it out!

Step 11: What Was Up With the Magnet?

The magnet was a great idea. The light can hang is some really great places. We have had it in a dark place in the basement, as a night light, and in our lockers.



    • Indoor Lighting Contest

      Indoor Lighting Contest
    • Make It Fly Challenge

      Make It Fly Challenge
    • Growing Beyond Earth Maker Contest

      Growing Beyond Earth Maker Contest

    24 Discussions


    5 years ago on Introduction

    Showed this to my partner and she loved it! Been trying to find uses for the constant accumulation of prescription bottles!

    1 reply

    6 years ago

    I think the hardest part of this project may be simply finding a film can. Where did you get yours, grandpa's abandoned darkroom?

    2 replies

    We hear that a lot but they can be found on e-bay pretty easily. We also have them at but look around you never know what you may find. Old cleaned out prescription bottles should work, for example.


    5 years ago on Introduction

    If making such flashlights is fun and/or educational, this is a fine project. But, you can buy cheap LED flashlights for less than the cost of just one toggle switch.

    Ronald Joseph

    5 years ago

    I made two and sent with my girls to Girl Scout camp. They said it was very helpful and they were happy they had them.


    5 years ago

    I bet that to improve the beam a small parabolic mirror could be stolen off a dollar store flashlight. Cool project, I always love toggle switches.

    Ronald Joseph

    6 years ago

    Very cool. Now if I could figure out away to not have to solder, I could use this with my elementary class. :-)

    3 replies

    simple, where the solder joints are required, such as the switch and the led ect, just twist the wire around the terminal then either electrical tape it or my preferred choice is to slide some heat shrink tubing over the join, then use a lighter, heat gun or even a hairdryer to shrink the tubing, that is the strongest connection without soldering ;) hope that helped :)

    The lid of the film canister is perfect for the one light but we like your idea. Perhaps we will try that. We have some fine tuning to this "flashlight" that we are going to share this coming up week.

    Nice Idea to made a flashlight with those simple parts. Especially the battery holder with two magnets :) Maybe you should describe which type of LED you used, that can be supplied by an 3 V battery.


    6 years ago on Introduction

    I think the altoids smalls work best o yea and why dont u use 3leds