First you need to gather up all of the materials you will need. Below is a list of the following items needed to conduct this project:

• 2 D batteries
• 2 5” pieces of #22 copper insulated wire w/ the ends stripped off
• A toilet tissue roll – cut to 4” in length
• A 3 volt flashlight bulb
• 2 brass fasteners
• 1” X 3” cardboard strip
• A paper clip
• Small paper cup
• Tape

Are you ready? Let’s get started. Push the brass fasteners through the tube and attach the paperclip. The paperclip will act as your on/off switch. Attach a wire to each fastener on the inside of the tube. Next, tape your batteries together (+to-) and place inside the tube. Take one end of wire and secure it to the bottom of one battery’s negative terminal. Take other wire and insert it through a hole in the center of the cardboard strip (the hole needs to be large enough to fit the bulb through). Then twist the wire around the bottom of the bulb and insert the bulb into the cardboard strip. This strip, when taped to the tube, will position the bulb for contact with the positive terminal on the battery. Punch a hole through the bottom of your paper cup and push the bulb through the hold. The cup will then act as your reflector. Secure with tape.

What happened? Did the flashlight work? It should have. If not, make sure your wires are connected securely. Back in 1898, the first flashlight was constructed and this is almost the exact same project.

30 Responses to How to Build a Flashlight

  1. pearl lyn says:


  2. nikita says:

    thanks you helped me a lot!!!!!!!!!

  3. got says:

    this is boring

  4. annalucy says:

    good one it’s cool for children to learn

  5. james B Davison says:

    Can you also use C cell battorys for the flash light. I’m restoring a boat that has a wheel house. The wheel house is 6 1/4 x 6 1/2 x 3″ I would like to light up the inside of the house.

    Jimmy D

  6. Ryan says:

    you shouldnt of skipped the procedures like at one point the screen went black and the one step was done but no one new how to do that step

  7. vvvvvvvvvv says:

    bad video quality. voice not clear

  8. ilze says:

    What a lovely project! We did it in class and the kids loved it. Just wanted to say thank you.

  9. Jenny says:

    Hi There,

    Love your experiment, my son is doing this for Intel Science week. We have been trying to get light working but it is not coming on. We have the brass fasteners and d cell batteries and we have a 2.4volt bulb which lights our flashlight with the same d cell batteries. Not sure where we are going wrong.

  10. kaytlyn wright says:


  11. kanarra says:

    This man talk a little bit toooooooooooooo much!

  12. onedirectioner#1 says:

    i am doing this for my last minute projects i am prying for it to work

  13. onedirectioner#1 says:

    i love it

  14. polly says:

    its simple and awesome

  15. Ezra says:

    this helped me so much on my school report!! Thank YOU

  16. MOrgann says:

    this didnt work its soo lame i swear sorry but it just dont work!

  17. Jimmy says:

    Need to have the paper clip touching both brass fasteners.

  18. Ali says:

    I love it AWESOME

  19. Matthew says:

    This is neat! Great little science experiment for kids to build their very own flashlight. Could imagine kids building their own flashlights for camping and cub scouts.

    Thanks for sharing the video.

  20. akhil kumar says:

    It helped me a lot in my science project

  21. shreyansh mallick says:

    I was worried about my project but this help me a lot

  22. jeniebai says:

    how long the, improvised flashlight give light

  23. jeniebai says:

    please reply?

    • Brittney Miller says:

      The flashlight run time will depend on the exact size bulb you use and the lifespan of your D batteries.

  24. leandre says:

    I never thought making a flashlight would be so easy:)

  25. ewob nerual nasuat alen says:

    I actually love this like oh my gosh i think my lifee has changed now. it gives me such a sense of worth, i can achieve anything now! Thanks so much!!!!!

  26. AbbuGail says:

    Nice !! 😀 it help me alot

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