Hybrid Fabrication: Combining Desktop CNC and Multi-Material 3D Printing
Bridging the gap between additive and subtractive methods allows makers to achieve industrial tolerances at home. We break down the CNC and 3D printing hybrid workflow.
The maker and prosumer manufacturing space is shifting from a reliance on standalone toolsets toward a hybrid manufacturing workflow. While high-resolution 3D printing excels at creating intricate internal cavities, complex infill patterns, and organic geometries, it often falls short on critical flat faces, bearing seats, and tight mechanical tolerances.
By combining additive 3D printing with subtractive desktop CNC milling, engineers can achieve industrial-grade precision in a small shop environment.
In this process, a part is first printed slightly oversized using an engineering thermoplastic like Nylon-CF or Polycarbonate. The print is then transferred to a desktop CNC mill, using locating pins or a reference touch-probe to align the coordinate system.
The mill is programmed to clean up mating faces, face off surfaces, and bore out bearing pockets to precise tolerances within hundredths of a millimeter. This combination enables the production of functional, end-use mechanical components with complex geometry and highly accurate interface surfaces.
This hybrid approach also opens up unique design opportunities for embedded components. For instance, a user can pause a 3D print mid-way to drop in threaded brass inserts, sensors, or wiring harnesses, and then print directly over them to seal them within the plastic core.
Once fully printed, the CNC mill can accurately cut precise o-ring grooves or register pins on the outer shell. This methodology eliminates the structural weakness often associated with post-print drilling and manual assembly, yielding a monolithic, highly functional end-use enclosure.