Case Study: Capo Bar & Yoke

Process: Metal Additive Manufacturing (AM)

Material: MIM-17-4 PH stainless steel

Density: 99.5% of theoretical

Hardness: 38 HRC

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End Use and Function

The capo is a device that temporarily shortens banjo strings, raising their pitch and allowing musicians to change the key of open-position chords easily.

Fabrication

Manufactured from MIM-17-4 PH stainless steel, the capo components are produced in their as-printed-and-sintered state with a relative density of 99.5% and a hardness of 38 HRC. Manufacturing tolerances are tight, with hole diameters held to less than 0.038 mm (0.0015 inch) and an overall yoke profile precision of 0.025 mm (0.001 inch). A slight bending operation shapes the parts, while polishing achieves the required finish. No secondary processing is involved.

Results

The capo delivers enhanced design flexibility and significant cost savings—50% compared to traditional machining. All critical components are sourced from a single manufacturing process, allowing for streamlined iterations. The additive manufacturing method also promotes material recyclability and reduces the carbon footprint, making it a more sustainable option for production.