Light up your LEGO #1

There is no doubt that adding lighting to a LEGO model will enhance it’s appearance – it adds a degree of life to it, enhancing lines, lightening shadows and highlighting features which may otherwise be a little obscure.  LEGO have offered lighting for at least 50 years, originally in the form of a light brick, with the options of a filter, and more recently with power functions, providing a pair of LED lights.  We now also see self-contained light bricks in recent sets.IMG_0691-2.jpg

While earlier  LEGO® sets used standard filament bulbs,  more recently builders have been able to look to Light Emitting Diodes (LEDs) to provide versatile lighting solutions. Recently,  LEGO builders have been incorporating lighting into their builds more often than ever before.

The systems used vary from simple ‘bulb and battery’ solutions, through to custom solutions for individual LEGO Sets.  There are also sophisticated, microprocessor controlled solutions available, providing preprogrammed sequential lighting patterns.  Miniaturisation of  LEDs means that they are now able to be incorporated in LEGO builds, with minimal rebuilding required for wiring.

Today, I would like to present a couple of simple options for cheap and easy lighting solutions, that can enhance your models.  In the future, I will present some examples of other, more sophisticated lighting solutions.

But First – What is an LED?

A Light Emitting Diode (LED) is a semiconductor that exhibiting electroluminescence: that is, what a current is applied across it, light is emitted.  Initially  emitting infrared light, LEDs emitting red light were first developed in the early 1960’s using a Gallium-Arsenic semiconductor.   Bright LEDs, emitting useful levels of lights were not commercially available until the 1990’s with white LEDs becoming available in the early 21st Century.  Typically, white LED’s are naturally blue, with a yellow/orange coating that exhibits a degree of fluorescence in combination with the blue light from the LED.annotated LED

The LED has two connections, the anode and cathode. Connect the anode to the positive terminal of the battery, and the cathode to the negative, and voilá: let there be light. Now,  being a diode- that is a semiconductor that allows current to pass in only one direction – if the LED is connected the wrong way round, no light is emitted. As you can see with the LED, there is a long wire, and a short wire.  This coincides with the round edge and the flat edge of the LED respectively, in turn this is, by convention the anode and cathode.  SO the long wire/round side connects to the positive terminal of the battery.

Now, the majority of LEDs purchased as single units have difficulty dealing with significant voltage. Typically, they work best across the range of 3 to 6 volts. A larger voltage than this being applied requires a resistor to be added reduce the voltage across the LED.  I vividly recall the day when, as a teenager recklessly dabbling with things electronic, I attached a red LED to the terminals of a 9Volt battery. It glowed red, then bright red, and smoke started to appear. There was an ear splitting crack and the light was gone. As was the plastic covering the LED. If I were to try it again, I would definitely use eye protection.  The Rambling Brick does not endorse the application of higher voltage to individual LEDs.  Seriously: don’t try this at home.

Quick and Dirty single LED Lighting.

I purchased some mixed LEDs: red, yellow, green; 5 and 3mm in diameter from an electronics store for around $AUD0.30 each.IMG_0704

The coin shaped 3 Volt CR2032 cells are a little mIMG_0651ore expensive, but can be found in a number of places. I found a packet of 8 for $AUD4 at a large Swedish flatpack furniture retailer.

I normally tape the LED onto the battery, and use Blu-tac or similar to attach it to the roof of a MOC.

You can achieve a similar effect using an electronic tealight candle.  These often have the advantage of a built in flicker circuit: great for simulating candlelight or a fire. You need to disassemble the tealight assembly and extract the LED and battery.  There will be damage to the case.  Do not worry: you will not be using it again.  I purchased six electronic tealight candles for $AUD3 at a homewares store.

This type of light is generally bright enough to use for around 12 hours, but you may notice the brightness drop off with time. This is useful for a short term light ( a day or two at a public exhibition, or a couple of photo sessions), but the battery will easily become exhausted over the course of a multiday show – essentially requiring daily replacement.


Installing just one in the ceiling of the Heartlake City Pizzeria had a remarkable effect on the downstairs ambience:

Left: No light; Centre: with a light, front view; Right: with light, rear view.

You do need to be careful with the Q&D setup.  It is important not to create a short circuit by having the LED leads touch each other, or connect the positive and negative sides of the battery directly.

As you can see from the pizzeria above, a simple light can enhance a simple model.

How does all this relate to LEGO system connections?

A 5mm LED can fit very snugly into a tube e.g. the base of a transparent brick (1×1 square or round), or a hole accepting a rivet style technic connector, such as a beam. Be aware though, the flange on the base prevents it passing through the hole completely.

Examples of a 3mm LED passing through a hollow stud, or through a brick with studs on the side, allowing for the LED to be redirected.

The 3mm LED will pass into, but not through, a 3.2mm hole, such as might be found in an Ehrling brick or similar. A little sandpaper may help it through a little more.

A little creative bending of the leads allows a 3mm LED to be placed inside a brick with studs on the side, and use a transparent plate as a diffuser, as seen with this jewellery store model.diamond

Not So Quick and Dirty String of Lights.

I recently obtained a string of 20 LEDs, powered by 2 AA cell batteries. Again, this cost

A clustered string of lights enabled this emerald city to glow in a delightful fashion.

around $AUD5 at a homewares store, but you may be able to do better.  I have encountered 2 types of LED string previously: one with a fixed cowling over the light – typically about 5-10mm long, and a little less than 5mm in diameter.  These were able to fit into 1×1 cylinders to provide luminescence for a microscale Emerald City that I built a few years ago.

The current version features wires with lacquer insulation – no bulky plastic – and small LED’s – less than 3mm. The LED casing seems to be a blob of resin, rather than a fixed plastic case.  I was able to draw the LED string through the 3.18 mm holes in a cylinder brick, or a 1×1 with 4 studs on the side,  This makes for easy threading of the string through a small hole in the wall or similar. the wires also fit between the flanges of some 1×1 round plates studs next to each other – allowing multiple lights to be positioned together. The gap between LEDs on this string is approximately 14 studs.

This string of ‘Twinkle Lights’ runs on 3 Volts, from AA cells. The wires are thin, and can fit in the gap between a round stud, and a brick adjacent to it; or through small holes in bricks.  If there is more length than you can use, simply cut off the excess LEDs: they are wired in parallel, so if one is broken, others will continue to work (unless the wire is damaged).  A hobby knife can be used to scrape lacquer of the wire to make it usable for other projects, but this is beyond the scope of this project.


Using this ‘Twinkle light, I set out to light up the 31605 Creator 3-in-1 town house.

One of 2017’s creator sets, fitting into a small scale modular building, this set is an excellent source of tan and sand green, and dark red bricks, as well as light stone grey masonry bricks. The rooftop garden, tree, fire escape, fences and brick built creatures (dog and bird) all provide detail to enhance the place of this building in the street. It’s a simple build, taking about an hour while being distracted by television.

This building provides some special challenges:  it has 2 sections, with multiple floors. To help fix the lights in place, I use plates with holes down the middle, and thread the LEDs through the holes (with the wire returning through the same hole.  I was able to hold it (roughly) in place by building up on the top of the plate with a plate and studs, to prevent the lights pulling through.

My standard lighting module for roof mounted downlights. If you don’t have plates with holes in, you can use normal plates, with the lights mounted at the front of them.  The studs remain useful to wrangle the wire in that situation.

I installed these units in each room, as well as a couple of lights in the basement fire place. Additional plates were installed in the ceiling, to redirect the wires.  I managed to tuck wiring into the ceiling of each room, but there remained visible wiresIMG_0710

I promised Quick and Dirty: this modification took around an hour, and I found all the pieces I needed to complete it in my collection, but is NOT neat and tidy.  I have not attempted to build the wiring through holes in the walls.  There are a few locations where this could work quite well.  I also did not do the obvious thing, which would have been to illuminate the streetlamp.

The final effect:

You can see the worth that the lights add to the model, as well as the additional detail within the building, such as the mini figures.


While not every room is thrown into bright illumination, there is no doubt lighting adds  warmth and atmosphere to the model.

In summary:

While this modification does not make a perfectly lit building, with completely concealed wiring, the lighting does enhance its appearance.  There are some additional challenges that could be met, including lighting the rooftop garden, and the tree, and also providing illumination for the street lamp.

A string of ‘Twinkle Lights’  is inexpensive, and allows and a high level of customisation for the model.  I recently found a much longer version, with 103 LEDs, for $AUD 10.  This could be cut into useful lengths of rigged LEDs (BUT I was setting out to create a non soldering, simple solution, so it is beyond the scope of this article.

Likewise, a simple ‘LED and coin cell’ light can add a remarkable amount of life to a LEGO® campfire, or for adding a simgle light to a building in a quick and simple fashion.

Both of these solutions are relatively inexpensive, and simple to implement. I cannot claim either of them as my own, but I have seen them rolled out in multiple MOCs that I have seen at shows over the years.

Have you used lights to enhance a LEGO® model that you have built, either a kit or MOC? Did you use more than the LEGO Powerfunction LEDs?  Why not comment below.

In the future, I will have a look at some of the customised lighting kits, as well as microprocessor controlled lighting systems that add a great deal more to your model.

Play Well!



5 thoughts on “Light up your LEGO #1

  1. I used woodland scenics plug and play nano lights – Individual leds plug into a lighting box and this plugs into mains and you can link huge distances via expansion boxes/more lighting hubs (great for lighting a whole length of buildings). Wires thin enough to work just putting the wire on brick/plate in your building between studs and the next brick/plate on top – can integrate while you build. No batteries and blissful simplicity. USA company but export to other countries. Sold in model shops – mostly used by railway modellers. Yes they cost more, but long term cheaper than batteries, and no issues running out of power while on show for however long you want them on for.

  2. I use the twinkle lights in my builds. I set per floor (shortened of course) and i run it around the studs below the final plate around the floor. However it can be very bright so i only do that for offices and shops and cut the lenght very short for living rooms and bedrooms. It takes time and if you do it right the bricks will still snap into place and the AA battery pack is at the back of the building.

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