Ten mechanism families to build and explore

This collection replaces the earlier fabrication interpretation. Explore real construction-part models with animated assembly and free illustrated booklets. Reviewed existing models are not relabeled as new catalogue additions.

• Pendulum Educational article and challenge Retained bob and pivot; chosen animation timing is not a measured period.
• Slider-crank Educational article and challenge Offset slider equation and full-cycle closure; paired guides and retainers.
• Four-bar linkage Educational article and challenge Full-cycle joint closure; retained pivots and braced ground frame.
• Rack and pinion Educational article and challenge Captured guide constrains rack escape across the authored ±8 mm travel.
• Worm drive Educational article and challenge Supported and retained shafts; reviewed worm pitch, direction and full mesh cycle.
• Differential Educational article and challenge Manual carrier bench with independent retained half-shafts; internal gear visuals are simplified.
• Escapement Educational article and challenge Contact-controlled release and retained supports; chosen timing is not physical clock accuracy.
• Cam and follower Educational article and challenge Mesh-fitted follower contact, fixed drum support and actual follower retainers.
• Lever Educational article and challenge Retained pivot; equal gear-only moments do not certify whole-body balance.
• Spur gear train Educational article and challenge Both meshes phased and checked; retained shafts and ideal equal-end speed lesson.