Trackballs are a fascinating input device with some genuinely tricky engineering problems: how do you support a heavy sphere so it spins with almost no friction, how do you sense its rotation accurately in two axes, and how do you keep dust and skin oil from gumming up the works? Scaling one up to "world's largest" size amplifies every one of those problems — bearing loads go up, sensor resolution has to keep pace with a much larger surface, and 3D-printed parts start hitting the limits of what a hobby printer can produce in one piece.

This is Part 1 of what looks like a proper build series from CalebBuilds, walking through the design decisions, CAD work, 3D printing, and prototyping of an oversized desktop trackball. The value here isn't just watching a novelty gadget come together — it's seeing someone reason through mechanical constraints out loud: bearing selection, sensor placement, how to mount a ball that's an order of magnitude bigger than a normal trackball's without it wobbling or dragging.

If you've ever wanted to design your own peripheral or you're curious about the mechatronics behind pointing devices, this is a great first episode to hop on. Small-channel maker content at its best: one person, one weird ambitious project, honest problem-solving.