A mechanical-design course project that followed a small product from CAD and tolerancing through analysis, mold planning, CNC planning, and assembly thinking.
PROJECT AT A GLANCE
The spinner is small, but it touches the complete mechanical workflow: functional requirements become geometry, geometry becomes manufacturing information, and manufactured parts must assemble and perform.
01 / Context
The fidget spinner's small scale made it a useful vehicle for practicing an unusually broad engineering workflow. Its geometry had to hold bearings, rotate freely, feel balanced, and remain manufacturable.
Rather than stopping at a model, the project connected nominal CAD geometry to GD&T, finite-element analysis, mold considerations, CNC planning, and final assembly.
02 / Approach
CAD defined the part and its interfaces, while tolerancing translated functional needs into allowable variation. Bearing fits and symmetry are especially important because small errors can affect assembly and perceived rotation.
FEA provided a structured way to examine loading assumptions, but it had to be interpreted alongside manufacturing. Mold direction, tool access, stock, setups, and assembly sequence constrain geometry differently, revealing why a design cannot be optimized in only one environment.
03 / Result
The result was a course-level design package and an end-to-end view of product realization. It is presented as a learning project, not a commercially manufactured product.
The project’s strength is breadth: one familiar object exposed the chain from design intent to drawing communication, analysis assumptions, process planning, and assembly.
04 / Reflection
A precise CAD model is only the beginning. Functional dimensions, datum strategy, tool access, process capability, and inspection determine whether another person can make the intended object.
A next iteration would define measurable spin and durability targets, build prototypes from competing processes, inspect critical features, and compare test results with the analysis assumptions.