6061T6 Aluminum Harmonic Reducer Housing 5Axis CNC Machining Case Study 4Axis Milling TurnMill Composite

This case study details our complete machining process for a harmonic reducer housing used in a collaborative robot. This component demanded extremely tight geometric tolerances and superior surface finish, presenting a typical challenge that showcases our machining capabilities.

The raw material was a 6061-T6 aluminum alloy forging. Our engineering team first reviewed the 3D model to identify critical mating surfaces (bearing seats, wave generator mounting bore) with strict tolerance requirements (all at H6 grade), and developed a optimized machining strategy.

• Step 1 - Rough Machining: Used a Vertical Machining Center (VMC) for initial cavity milling to quickly remove the bulk of the material, leaving a uniform 0.5mm stock allowance for finishing.
• Step 2 - Semi-Finishing & Benchmarking: Transferred to a 5-axis machining center. First, we precisely milled the bottom face and locating pin holes to establish an accurate datum. Then, utilizing 5-axis simultaneous machining, we performed semi-finishing on the complex curved surfaces and irregular features.
• Step 3 - Critical Finishing: The most crucial step. Using ultra-precision Japanese tungsten carbide end mills in a temperature-controlled environment, we performed fine milling and boring on the bearing bore and end faces. By carefully adjusting spindle speed, feed rate, and depth of cut, coupled with ample coolant, we ensured dimensional stability and achieved the required surface finish of Ra0.8. The flexibility of the 5-axis machine allowed the tool to maintain the optimal contact angle with the workpiece, guaranteeing perfect geometric accuracy.
• Step 4 - Deburring and Cleaning: Experienced technicians performed meticulous manual deburring, particularly on all cross-holes and sharp edges. The part was then thoroughly cleaned and dried in an ultrasonic cleaner.
• Step 5 - Surface Treatment: As specified by the customer, we applied a hard anodizing treatment (black) to increase surface hardness and wear resistance.

Upon completion, our quality inspector performed a full dimensional scan inspection using a Coordinate Measuring Machine (CMM), comparing the results against the original 3D model. All critical dimensions, including concentricity and face runout, met and even exceeded the drawing specifications.

The final product perfectly met the customer's assembly requirements, achieving zero-clearance fit with internal components. The customer highly commended our machining precision and process control, and the project has now moved into the mass production phase.