But his most recent project –a LEGO mosaic printer– is easily the most impressive yet. It’s essentially a cross between a 3D printer, a traditional inkjet printer, and a scanner. Built with a LEGO Mindstorms EV3 set, the machine can scan an image, and then create a mosaic of it.
The printer is constructed completely out of LEGO parts and prints exclusively with LEGO bricks. The machine uses an EV3 color sensor to scan the source image and saves the data to the Mindstorms unit, which is then used to print multiple copies of the image directly from the scanned image data.
The printing plates used in the printer operate on a gravity-feed system. The printer’s head is basically a 1 x 1 LEGO round plate capable of picking up and placing other plates within the printer. The LEGO printer can hold up 450 plates in up to nine colors.
As you can see in his video demonstration, the first row on the printing plate is referred to as the legend. The legend instructs the program where to pick up the colors that are needed for the image from the printer’s supply.
Initially, Allemann had wanted to scan his desired images and have them pixilated based on the colors of the plates in his supply, but his EV3 color sensor wasn’t advanced enough to handle the task, so he had to work with pre-pixellated images.
Allemann documented his progress in a series of additional videos, where he explains each part of the production process in great detail. He even alludes to an upcoming LEGO-based 3D printer!
