LIFE-SIZE LEGO BUGATTI
Want to build your own supercar? Here’s how Lego built a drivable, life-size Bugatti Chiron replica from a million pieces of plastic
We’ve found the ultimate Christmas gift: a Lego Bugatti Chiron. You can buy the model kit now, but not before reading how Lego built a life-size one from over a million pieces of plastic…
When Lego announced that its next deluxe Technic model would be a Bugatti, the company invited us to visit the car maker’s test track in Germany. Not to see the small model, but something more mind-blowing: Lego has built, from over a million pieces of Technic, a life-size Lego Bugatti Chiron… That actually drives.
Weighing around 1,500kg, the car is built pretty much solely from Technic pieces, with the exception of a steel frame (necessary for supporting all that weight), wheels (necessary for being round in a way that Lego is not), hydraulic brakes, power steering, a roll cage (just in case), and a few other mechanical pieces that really can’t be made of plastic.
It’s the first Lego creation of this kind of scale to be built without using glue to hold the pieces together, and that also means it’s the first time Lego had to build load-bearing sections purely from Technic. Even more impressive is that the car was so complex, the computer modelling systems the team normally uses couldn’t handle all of the design, so most of it was planned by hand.
“The first beams were built on a table, and we were testing the properties of them and what they could withstand,” explained Pavel Volný, an engineer on the project.
We were curious about how the team kept track of how it was going to look and fit together at the final stages with no fully planned model to refer to. “We almost lived together for like a quarter of a year,” said Pavel. “We were discussing things ad hoc, on the spot. We had to be sure that each and
every member of the team had the right information at the right time.”
The need for the car to support its own weight on Lego connections alone led to some complications in the way it was built, from the centre out. For a start, the body isn’t connected to the steel frame in any fixed way. Instead it just sits on it, held in place by gravity and a brick structure that wraps around the frame.
STUCK IN THE MIDDLE
This approach meant that once the team started building on top of that core structure, they were kind of stuck with it. “In the beginning we had to make a lot of decisions with the design crew, because we knew that it wouldn’t be easy – or even possible – to change things,” explained Pavel. “If you want to change some special part which is inside, I’m not sure you’d be able to reach it. But we decided that we definitely need to change the engine and make it easy to change.”
The engine is a feat of engineering in itself. The car is equipped with a huge power pack built from Lego Technic Power Functions motors. Normally, these do things such as making conveyer belts move on models only a couple of feet long. Here they make a full-size car drive. The trick is sheer numbers: over 2,300 Technic motors are connected into one huge engine block. This is divided into 24 motor packs, each comprising 96 individual motors. On top of that, 96,768 Lego gears transfer the power to a 3D-printed carbon fibre gear wheel, connected to the drive shaft.
The end result is a whopping 5.3 horsepower, aimed to push the car up to around 30kph. This, admittedly, doesn’t quite match up to the 1,479 horsepower and 400kph (248mph – that’s electronically limited) of the real Bugatti Chiron.
In fact, the engine was the most challenging part of all from a mechanical perspective, and not just because it includes well over 100,000 parts connected intricately. The first version was running way too hot: 70°C, to be exact. The motors couldn’t be changed for something else, and it couldn’t be made much larger, so the team experimented with reducing friction. They ended up using Teflon washers and silicon grease around the rotating parts, which reduced the temperature to a safer 32°C.
Having conquered the trials of the structure and the engine, one huge challenge remained: how to best mimic the curved look of the Chiron using the square angles of Lego.
The colour was relatively easy…
96,768 LEGO GEARS TRANSFER THE POWER OF
2,304 ELECTRIC MOTORS TO A 3D-PRINTED CARBON FIBRE GEAR WHEEL
Technic pieces were specially created in the correct hues to copy the look of the real Chiron. However, the pieces were still the same hard shape.
The solution to this problem is the most visually spectacular aspect of the entire car, and mind-blowing in its ingenuity: they created a Lego fabric. The mottled effect you see in these pictures is a result of the Lego Chiron’s outer ‘skin’ being made of triangles built from Technic pieces, in two different sizes, all tessellated together. Hold a sheet build from this design out flat and it flexes, like a woven material.
The car itself has an underframe of Lego, with a series of pillars sticking out from it, at different heights. The ‘skin’ is mounted onto these pillars, and so the way it sits over them creates those all-important curves.
Each of the pillars is actually a linear actuator, which means they can all have their heights individually adjusted by reaching through the gaps in the skin and screwing. It means the skin’s shape can be fine-tuned, even when it’s on the car, to make sure the organic look is perfect. This was originally done by hand, but it was wrecking the team’s wrists. A drill was too powerful to do it precisely, so they built a custom low-power electric drill for this specific purpose out of – yep, you guessed it – Lego.
Recreating the look has been managed even better in other areas. To echo the carbon fibre weave areas on the original car, a special weave of Lego was created for those parts. To create the dramatic rear lights, the first ever transparent Lego Technic bricks had to be produced.
That wasn’t the only extra mile the Lego team went to for the lights. They run on an electrical system (controlled through an app, which talks to an adapted smart home controller buried deep in the body) that makes them light up in a pattern that copies exactly the way the original Chiron lights up when turned on, playfully flashing along the strip of its headlights.
The final crucial detail to get right was the rear wing. The Lego car’s five horsepower may mean it doesn’t have the need for a dramatic air brake, but it’s not a Chiron without one. The Lego car’s wing is pneumatically powered, with the air stored in eight Lego Technic pneumatic tanks. They take a few seconds of priming, but then it’s just a matter of a tap in the app to raise the wing to its brake position.
Agonisingly, our visit to the Buggati test track was on the only rainy day they experienced there all summer, so we couldn’t actually test the drivability (and comfort of that all-Lego interior). Well, we guess that’s the peril of a gappy, plastic electric car.
RIGHT During construction, and with the car all in one piece, the team starts adding details and layering on the Lego skin
LEFTThe inside is fully detailed and faithful to the original, though perhaps a tad pointier when it comes to curves
LEFTEarly sketches of the concept for the skin, which looks a little like designs for the Spider-Mobile
It has the menacing look of the actual car, despite having the power of an elderly donkey