Italian Musical Instrument Supplier × Honscn Manufacturing: CNC Precision Machining for High-Performance Drum Ball Nuts

Project Challenge: The triple challenge of balancing functionality and acoustic performance​

Complex structure and high precision requirements​

• The four ball nuts are made of nylon (PA66) and brass (C36000) respectively, and need to achieve a concentricity tolerance of ±0.02mm and a surface roughness of Ra≤0.8μm. The matching accuracy between the nut spherical surface and the drum head bracket directly affects the resonance transmission during striking. Traditional processing technology is difficult to balance complex curved surfaces and high precision requirements. ​

Invisible test of acoustic performance​

• The customer emphasized: "Small flaws on the surface of the nut will cause sound distortion." The shock absorption characteristics of nylon and the resonance conductivity of brass need to be precisely balanced. Any residual processing stress or surface ripples may cause the drum sound to be turbid and lack of sustain.​

Difficulties in adapting multi-material processing​

• The low melting point of nylon (260°C) and the high hardness of brass (HB 80-100) are in sharp contrast. The same processing parameters cannot meet the molding requirements of the two materials. Traditional equipment is prone to nylon deformation or brass tool wear.

Solution: CNC precision machining and acoustic optimization​

Customized CNC machining process​

• Dual-path programming strategy: Develop independent CAM machining paths based on the characteristics of nylon and brass. Nylon nuts are cut at low temperatures (cutting temperature ≤ 80°C) with diamond-coated tools to avoid softening and deformation of the material; brass nuts are milled at high speeds (speed 12,000rpm) with an internal cooling system to reduce tool wear and ensure surface roughness of Ra ≤ 0.6μm. ​
• Five-axis linkage surface forming: Using DMG MORI five-axis CNC machine tools, complex spherical structures are formed in one go through five-axis linkage technology, and the concentricity tolerance is controlled at ± 0.015mm, which is 25% higher than the three-axis machining accuracy.​

Acoustic-guided surface treatment​

• Nano-level polishing process: The brass nut is electropolished to remove 0.01mm of the surface layer to eliminate processing stress; the nylon nut is treated with vibration grinding + chemical coating to form a 0.005mm dense lubrication layer to reduce the friction noise with the drum head bracket. ​
• Acoustic simulation test: The Danish B&K acoustic analyzer is introduced to install the nut on the standard drum rack for 1000+ simulated knocking tests. The surface texture is adjusted through spectrum analysis, and the sound attenuation rate is finally achieved. ≤3%, which is much better than the industry average of 5%. ​

Full process quality control​

• First piece 3D scanning verification: Use German Zeiss Industrial CT to perform 1:1 digital modeling of the first piece, and correct 0.005mm level slight deviations by comparing with the design drawings; ​
• 100% full inspection mechanism: Each batch of nuts must pass the three levels of size inspection, surface roughness measurement and knocking sound quality inspection to ensure zero defective products outflow.

Project Results: From Sample Approval to Volume Production​

Key Metric Achievements

Customer Comments​

"The nuts made by Honscn exceeded our expectations for acoustic performance! The smooth surface and precise size make the drum sound purer and fuller. What's even more surprising is the 12-day delivery, which perfectly matches our new product launch plan!"​

—— Luciano Rossi, Director of Customer R&D

Industry value: Precision manufacturing enables innovation in musical instrument acoustics

This case showcases Honscn Manufacturing's leadership in precision machining for musical instrument components, especially in applications sensitive to acoustic performance and surface quality. By integrating customized CNC machining, acoustic optimization techniques, and end-to-end quality control, we empower global musical instrument brands to achieve breakthroughs in both sound quality and manufacturing precision.