Beyond Manual Sanding
Hand sanding is labor-intensive, difficult on complex internal geometry, and prone to uneven pressure spots. For production runs of 20 to 500 parts, automated mechanical finishing provides consistent industrial aesthetics.
1. Bead Blasting
Bead blasting bombards parts with fine media (typically 60 to 120-grit soda lime glass beads) using pressurized air (4-6 bar):
- Aesthetic Result: Removes the shiny gloss of FDM thermoplastics, blending layer boundaries into an even, satin-matte finish.
- SLS Depowdering: For nylon SLS prints, bead blasting removes stubborn sintered semi-melted powder particles from exterior crevices.
- Cycle Time: Under 60 seconds per part in a standard blast cabinet.
2. Vibratory Tumbling
Vibratory tumblers place parts in a vibrating bowl filled with abrasive media and liquid surfactant:
- Deburring Stage: Heavy triangular ceramic media removes support pockmarks and sharp edges over 2-4 hours.
- Polishing Stage: Walnut shell media impregnated with polishing compound provides a smooth semi-gloss sheen over 8-12 hours.
At FamilyMake, batch tumbling and bead blasting give local African prototypes the polished surface quality of global consumer electronics.
