3D Printed Bike Light (rear) Without Battery




Hi buds !

Here is the second version of the 3D printed universal bike light for the rear of your bike !

HD quality for the timelapse is available !

Step 1: What You Need

Take everything you need : (kit available soon !)

Magnets (could work with hard drive ones)

coil from a relay ( you can find in any electronic shop)

2x LEDs 10000 mcd or more if you find to shine in the night !

2x 10-32 Screws and bolts to tight the light

2x 4-40 screw and bolts to tight the magnet on the wheel

Ring which fits on your bke ( you can find from old bike parts) soon 3D printed

Rubber bands

3D printed parts :

Support of the coil

Top of the box

Link to fix the light on the ring of

Tools :


Soldering iron

Eventually glue

Atmosphere to assemble it :

Music : free of your choose, I suggest nice radio, classics works well, Rolling Stones, Nina Simone, Vivaldi…

Friends : try to find cyclist they’re often more interested

Well… stop joking, let’s assemble it ! Count 5-10 minutes to do it

(As for everything the more you prepare the fastest it goes !)

Step 2: Solder the LEDs

Take the 2 Leds and the coil.

Solder it so that each LED is in a different way, one positive, one negative.

The electricity you’re making is a wave, so the aim is to take the positive AND the negative side of the wave. LEDs only works in one way !

Step 3: Solder the Coil

Solder the coil

Once done, solder the 2 LEDs on the coil

And cut the mustach of those cute Leds ;)

Step 4: Clean the Desk

Don't forget to put those small things in the garbage

So easy to let it down and it finishes in your foot or in your favorite pet's mouth.

Step 5: Assemble the 3D Printed Things

Take the 3D printed parts and put the coil with the LEDs

inside, it should fit perfectly

Same with the top, normally no glue is required.

Step 6: Prepare Before Fix It to the Bike

Take the screws ans bolts and assemble the parts so you would be able to fix it on your

Step 7: Magnetize Your Wheel !

take the magnet and put screw it on your bike.

Step 8: Adjuste the Light to Your Bike

Fix the light on your bike and adjust it so the magnet

passes in front of it, as close as possible, but it should touch it ! This is friction less system ! Feel free to make it touch if you want but that’s not the aim and it won’t last as long as expected.

Step 8 : Test it, just turning the wheel, ask someone to do

Step 9: Test It


it, just turning the wheel, ask someone to do it and check the angle which the light is is seen by cars.

Step 10: Cycle Safe Days and Night !

Now you’re able to ride all night long with a light without

battery !

Show off on cycle path, take pictures, send me some, and share the « one bike one light » project to your friends and neighbours.

« Everyone should have access to batteryless bike light, this is my first step to upgrade the world »

Please pay it forward.


Step 11:



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    9 Discussions


    2 years ago

    Nice one!

    Would it work with a Sigma bike computer magnet?

    It would be a lot smaller and easy to just screw on...

    1 reply
    Alex Poptuonoko

    Reply 1 year ago

    definitely not,

    You need power to power your LED and small magnets don't have enough strength to give a sufficient power.

    It will work, but definitely you'll pay the price by a lower brightness.


    2 years ago

    So freaking cool. What program did you use to design the parts?

    2 replies
    Alex PopJON-A-TRON

    Reply 2 years ago

    I used solid but I'm moving on fusion 360 to make it more universal

    JON-A-TRONAlex Pop

    Reply 2 years ago

    That's why I use it. I'm hoping that since it's free, more people will get into 3D modeling.


    2 years ago

    Very well engineered and executed! What material did you print the parts in?

    1 reply
    Alex PopDylanD581

    Reply 2 years ago

    I actually use PLA which works pretty well, a kit would be very soon online !

    what is your 3D printer ? ( ps I just received a wood filament, would be interesting ^^ too easy too easy ..)


    2 years ago

    Add more Magnet to the wheel and you will see the different.

    Morre safer.

    1 reply
    Alex PopElecTea

    Reply 2 years ago

    Thanks man ! I tried out but not seemed to be really really different, maybe magnets were too big, it should be better to have smaller ones chqnging quickly the field through the coil, but really appreciated ! thabks for your suggestion