Grit on Instagram: "This creator spent months engineering a fully functional mechanical marble clock made entirely from 3D printed parts. What started as a simple maker project quickly became a complex test of precision engineering, patience, and problem solving. Tracks jammed. Lifts stalled. Entire sections had to be redesigned, reprinted, and carefully hand-finished just to achieve accurate timing. The balance between gravity, friction, and gear alignment turned this DIY marble clock into a tr