Fully-Automated LEGO Car Factory Can Churn Out Three Vehicles in a Row

Banana Gear Studios has created a fully-automated LEGO car factory, which is one of the most impressive projects to emerge in recent years, or at least in our eyes. This time, instead of spitting out a single, simpler LEGO car, the factory produces three in fast succession, each gliding off a ramp as a fully completed model.

At the center of this operation is a 3-axis gantry system built with LEGO Technic pieces. This overhead setup moves a slim grabber precisely along the X, Y, and Z coordinates. Long axles operate as rails supported by rollers, allowing the entire thing to move smoothly. To ensure precise accuracy down to a fraction of a millimetre, the builder added some tensioned chains to minimize any backlash. Early iterations of the factory had problems with the gantry flexing and swaying while moving quickly, so the builder beefed up the support with some diagonal struts and an extra layer of beams, which totally altered the structure.

Each car is divided into seven standardized sub-assemblies: chassis, front wheels, rear wheels, engine, front body, rear body, and windscreen, all of which are stored on pallets in predetermined positions with identical size and connection points so that they can be used for all car variations. The grabber removes one sub-assembly at a moment, transports it to the central assembly platform, and secures it with a controlled downward press. A small wiggle during installation guarantees that everything lines up perfectly, compensating for any minor variances in stud type or minuscule size deviations. Once the growing automobile is complete, it simply rolls off the platform onto an exit ramp.

Getting the factory to be reliable was a big pain, as Banana Gear Studios initially only got around 94-95% of the attachments just right, then he worked out numerous mods to get it even higher, altering movement offsets, press time, and even battery voltage to get things operating smoothly. Even more impressive, the entire sequence was programmed using the LEGO Mindstorms hubs, which mapped out each step on a 3D grid to ensure consistent output.

The next major accomplishment was a pallet-swapping device, which eliminated the need to manually swap large amounts of parts for each new car. A rotational assembly with three pallets spins clockwise and is led by a locking system that keeps everything neatly lined up; a second Mindstorms hub controls all of this via Bluetooth, ensuring that everything works together in harmony. After one car is completed, the system simply switches the pallets with the next set of parts, allowing the factory to continue constructing three vehicles back to back with no effort. There are still a few little hitches here and there, such as a stopped rear body or a dropped part that miraculously pops into place, but the overall flow is still very seamless.

This concept offers a lot of room for customization; by playing with the pallet system to shift between different sets of parts mid-assembly, utilizing a color sensor grid (red, blue, yellow) and a simple selection, the factory can construct some really wild and wacky cars. One run may result in a hybrid car with an orange chassis, white wheels, and a red engine. The vehicles themselves are just some simplified LEGO Speed Champions styling, kept nice and compact at only 8 studs wide and 20 studs long to keep everything under the grasp of the grabber and the gantry’s 32-module axle restriction.
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