Precision 6061 Five-Star Spline Hub Flange with Stress-Relief Machining for Thin-Thick Transition Control

We successfully manufactured a precision 6061 aluminum five-star spline hub flange for a compact transmission application. This complex structural component features five radiating arms with thick-to-thin wall thickness transitions and internal arc-shaped lightening slots, presenting significant machining challenges — including stress concentration at transition zones, post-machining distortion, and internal corner clean-out in curved weight-reduction features. Through optimized machining sequences, stress-relief strategies, and custom fixturing, we delivered dimensionally stable hub flanges with clean internal geometry.

Project Overview

Key Technical Highlights

• Stress-Relief Transition Control: Implemented balanced material removal sequences and staged machining to manage stress concentration at thick-thin arm transitions, preventing post-machining distortion and maintaining flange flatness ≤0.01mm.
• Distortion Prevention Strategy:
  • Symmetrical Machining Sequence: Alternating material removal across radial arms maintains balanced stress distribution throughout the machining process.
  • Low-Stress Fixturing: Custom workholding solutions minimize clamping distortion while providing secure part retention.
  • Intermediate Stress Relief: Controlled machining pauses allow stress relaxation before final finishing passes.
• Internal Arc Slot Clean-Out:
  • Specialized Toolpath Strategies: Optimized contouring toolpaths with smaller-diameter finishing tools achieve clean internal corners in arc-shaped lightening slots, eliminating stress risers and material buildup.
  • Corner Radius Optimization: Minimal achievable corner radii maintained while ensuring proper material removal and surface finish in confined internal geometries.

Quality Verification

Each component underwent comprehensive inspection using CMM measurement for radial arm positional accuracy (±0.015mm), flange flatness (≤0.01mm), and overall dimensional tolerance (±0.02mm), supplemented by visual inspection of internal arc slot corners and surface finish verification.

Industry Applications

This solution demonstrates our expertise in precision transmission component manufacturing, ideal for:
✓ Compact transmission hub flanges ✓ Micro-drive system components ✓ Lightweight power transmission parts ✓ Robotic drivetrain elements

Why Partner With Us?

• Proven expertise in stress-relief machining for thick-thin transition components
• Advanced distortion prevention strategies for complex geometries
• Precision internal feature machining with clean corner finishing
• 12+ years of precision manufacturing experience across transmission and robotics sectors