LEGO LED LIGHT (mini Flashlight, Led Light)




This instructable will show you how to make a cool and very useful mini LED flash light that will prove very useful.

I don't know if this has been made before. I decided to make one because I wanted to make something myself because I find it gives me a sense of achievement.

I was motivated to make this because I hate not being able to find the key hole for my car, this is not only annoying but you can accidentally scratch the paint on your car. (I don't have central locking)

Step 1: Things You Will Need / Ingredients / Materials


> 5mm LED (colour of your choice)

> Small 4x2 LEGO brick (colour of your choice)

> Switch or momentary on switch (I used one of the small square ones because they are easily found and easy to use)

> Small gauge wire

> Soldering iron and solder

> Hot glue gun and glue sticks

> A key ring (I didn't use a key ring but used some thick electrical wire)

> 3 mini cells (I got mine from a A23 battery)!-You_ll-be-Surprised.../

> Some way to hold the cells (see pictures)

> Dremmel (Not necessary but useful)

Step 2: Step 1 --- Lets Get Started

The first thing you will need to do is to hollow out the LEGO brick, I used a dremmel to do this.

After the brick is hollowed out you will need to make a hole at one end for the LED. I used a 5mm LED so I used a 4.5mm drill bit, just to be sure it was a good fit.

After the brick has been hollowed and a hole made for the LED you will need to decide where you want the switch to go. I decided to put mine on the side.

I did a dry fit just to make sure it would all work, it turned out to be a good idea as I had the switch around the wrong way.

Step 3: Step 2 --- Fitting Everything In

Now comes the tricky part, getting the cells to fit into the LEGO brick and to wire up the switch. I used some very small gauge wire since there was only going to be 4.5 volts through the circuit.

To make the cells fit I had to get a small bit of thin plastic and wedge it inside the LEGO brick and hot glue it in place. At the other end I used a small spring to make sure there was a decent connection between the cells. (confused? see pictures)

Once the cells can be secured the wiring can then be set up.

Step 4: Step 3 --- Wiring and Gluing

This step will show you how to wire up your mini LEGO flash light.

It is a very simple circuit to create because it only entails three things: The LED, Switch and cells.

Below is my half ass attempt of a wiring diagram!

Step 5: Step 4 --- Check That It All Works

Now check all your connections and make sure everything is good. If it doesn't work make sure you have connected your switch up properly then test the LED and make sure its in the right way (check polarity) and if it still doesn't work check that all the cells are touching and facing the right way.

Thanks for viewing, as you can see by the pictures below its a pretty bright light. I think i would have preferred a white light but the blue still looks cool and works well.

NOTE: I drilled 2 small holes in mine to connect up to my key chain, this step is not necessary but can be very practical / useful.

If you are having trouble with the key chain i have a picture below of ho mine looks.

Send me pics of all your LEGO Light creations!!!



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    14 Discussions


    Reply 9 years ago on Introduction

     Yes, I just glued it in with some hot glue. When i glued it i also filled the empty spaces inside with some glue just to make sure nothing moved about.


    9 years ago on Step 5

    Very nice, I assume you used a 2x4 lego brick for the underside, my question is do you cut off the circular on th top of it before glueing it on or not - or does it not matter?

    1 reply

    Reply 9 years ago on Introduction

    i started by using a pocket knife but it was taking to long so I got out a dremel and with one of the sanding attachments was able to hollow it out well. hope this helped


    9 years ago on Introduction

    Would it be possible to put the switch inside the lego brick and just have the actual circular button poking out?

    3 replies

    Reply 9 years ago on Introduction

    Yes, it would probably work. It's a good idea but you would have to carve out some of the brick from the inside to make sure the button was able to be pressed.


    Reply 9 years ago on Introduction

    Aaa ye cool I may just leave it on the outside then...also how do you wire up the switch...I have one like yours with 4 all 4 have to be wired together?


    Reply 9 years ago on Introduction

    no, you only have to wire up to 2 of the prongs, its a little bit of trial and error getting the switch configuration right.


    9 years ago on Introduction

    nice ible, I remember trying to make one like this when I was young; however I only got as far as getting a light bulb!