When is a LEGO creation, not just a bunch of bricks stacked atop each other? When these bricks are transformed into working machines, like a Rolls-Royce engine (above), a go-kart (bottom), or even a robotic arm. Continue reading to see five of the world’s most complex LEGO creations.

5. Robotic Arm

Unlike other LEGO creations, Max Shepherd used the bricks to create a robotic arm that mimics the full range of motion of a human hand, and can even lift a couple pounds. The softest grippy hands we have seen don’t look human at all, so this is quite a feat. Watch the fingers curl softly around a water bottle or other object.

4. Go-Kart

This may not be the fastest homemade go-kart, but it’s definitely one of the most unique. Simply put, it “makes use of 48 Lego Mindstorms NXT motors and 16 NXT battery packs, has working headlights and taillights and can support the weight of a 222-pound adult man; it is constructed exclusively from Lego parts, too – no cheating.

3. Motorized Wheelchair

Geek and brick master Simon “Burf” Burfield has built the world’s first motorized LEGO wheelchair. At 44-pounds, it was made “from six Lego Mindstorms NXTs, 12 Mindstorms motors, 12 Lego Mindstorms touch sensors, 12 Rotacaster mult-directional wheels and a ‘whole load of Lego Technic.'” It’s not the fastest wheelchair available, but where it falls short in speed, it makes up in carrying capacity. Burf says that his Lego wheelchair can carry a 90kg person (198 pound). Right now, the wheelchair is driven by a four-direction joystick, but Burf hopes to get Bluetooth working so that it can be controlled by an Android device.

2. Land Rover Defender

More than just a model, this 2800-piece LEGO Land Rover Defender 100 by “Sheepo” actually works. Made with 2800-pieces, “it has fully functional steering, a five-speed transmission with reverse, two-wheel and four-wheel drive modes for serious off-roading, full suspension, and working disc brakes on every wheel.” As with any Lego creation that’s worth its weight in bricks – in this case almost seven pounds – Sheepo’s Land Rover is even more impressive underneath its detailed body which can be easily removed with just four pins.

1. Rolls-Royce Engine

Believe it or not, this life-sized Rolls-Royce Trent 1000 engine was made with 152,455 LEGO bricks, weighs 677 pounds (307kg) and measures 6.56-feet long (2m). More than just a sculpture, it also shows its inner workings, “including everything from the large fan blades which suck air into the engine down to the combustion chambers where fuel is burned.” The engine’s blades rotate just like the real thing, though given their plastic construction, they remain a little slower and a little less powerful. While the real engine weighs in at 1.25 tons, the LEGO replica still weighs a hefty 676 pounds and measures 4.9 feet long and 6.5 feet wide.

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