Rolling Ball Bearing Model

A textbook ball bearing, rendered as a print-ready mechanism. This is a rolling-element bearing in miniature: a broad outer race rings a stepped inner race, and between them sits a full circle of spherical balls, evenly spaced around the raceway so the whole assembly can spin. The image shows it from two angles — a flat ring behind and an angled view down the central bore — making the geometry of races and rolling balls easy to read. It's an engineering shape, not an ornament: clean, functional and satisfyingly mechanical. Great for STEM demos and classroom show-and-tell, as a chunky desk fidget, or as a working detail inside a larger mechanical build or model. Print notes • For a spinning result, print the outer race, inner race and balls as separate parts and assemble — captive balls need generous clearance (0.3–0.4mm) to roll. • PETG or ABS give smoother, longer-wearing races than PLA; a fine layer height keeps the ball seats round. • Orient the rings flat on the plate to avoid supports inside the bore; deburr the raceways before assembly. • Also machinable — the concentric races turn cleanly on a lathe or CNC — but it's happiest as a printed teaching or fidget model. A drop of dry PTFE lube frees up the spin.