LEGO enthusiast Jason Allemann of JK Brickworks created a simple spirograph style LEGO drawing machine that can draw five patterns. Made with just under 100 pieces, it consists of a turntable, an armature, two anchors, and a gear train. He shows how it all works in the video below:
…the central gears will result in the pattern repeating 27 times in one rotation of the paper. You can customize this ratio by replacing any pair of meshed gears. For example, instead of using one 8 tooth and one 24 tooth gear, you can use two 16 tooth gears, or one 12 tooth and one 20 tooth gear.