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High-Precision Profile Finishing Solution for AC2B-T6 Scroll Compressor Wrap
This case study focuses on the complex profile finishing of an automotive scroll compressor wrap manufactured from AC2B-T6 aluminum. The primary challenge lies in maintaining extreme perpendicularity across the scroll walls, achieving a flawless surface finish without chatter marks, and strictly controlling the tight bottom R-angle during high-speed machining. By engineering a custom 4-flute end mill with highly refined edge preparation and optimized tolerances, Sundi delivered exceptional dimensional accuracy and a significant reduction in cost-per-part for automotive climate control systems.
Project Overview
| Component Name | Scroll Compressor Wrap |
| Workpiece Material | AC2B-T6 Aluminum Alloy |
| Industry Segment | Automotive Tier 1 – HVAC & Compressor Systems |
| Equipment Type | Makino L2 Vertical Machining Center |
| Spindle Interface | HSK-A 50 (Emulsion Cooling 8-12%) |
| Core Challenges | Profile perpendicularity < 0.01 mm, surface roughness Rz < 12.5, eliminating wall chatter marks. |
Profile Characteristic & Requirements
The workpiece presents several technical hurdles that standard tooling often fails to address in high-volume production:
Strict Perpendicularity: Maintaining inner and outer profile perpendicularity strictly under 0.01 mm, requiring exceptional tool rigidity and deflection control.
Surface Finish Quality: Achieving a perfectly smooth, chatter-free groove bottom and side wall with a surface roughness better than Rz 12.5.
Tight Corner Radii: Controlling the groove bottom R-angle to a strict maximum of 0.12 mm.
Precision Tolerance Allocation: Demanding extremely tight tolerance control on the tool itself to match precise machine tool compensation requirements.
Sundi’s Integrated Tooling Solution
We developed a highly specialized finishing end mill to optimize this critical profile machining stage:
Precision Profile Finishing
This stage focuses on achieving the final dimensions, perpendicularity, and mirror-like surface finish of the complex scroll geometry.
The Challenge & Solution:
Refined Edge Geometry: Manufactured with an ultra-fine edge preparation process to virtually eliminate edge serration. This directly solves the issue of chatter marks, ensuring a brilliantly smooth surface finish (Rz < 12.5) on both the walls and the groove bottom.
Optimized Tool Tolerance: Implemented a strictly shrunken tool diameter tolerance (0 to -0.01 mm) for the Φ10 tool. This guarantees optimal baseline accuracy, allowing for highly precise machine tool radius compensation.
Strategic Tool Pathing: Designed to accommodate a tailored multi-pass approach (0.05 mm roughing, 0.02 mm finishing allowance) across 4 internal/external laps. This minimizes cutting forces and deflection, guaranteeing the strict < 0.01 mm perpendicularity.
Machine Environment Constraints:
Cooling: Single-axis external cooling
Max Spindle Speed: 16,000 RPM
Spindle Power: 20 Kw
Max Tool Weight Capacity: 5 KG
Processing data
| Operation (OP) | Tool Diameter D (mm) | RPM (rev/min) | Vc (m/min) | fz (mm/Z) | Feed rate vf (mm/min) | Depth of cut ap (mm) | Teeth (Z) | Allowance (mm) |
|---|---|---|---|---|---|---|---|---|
| Profile Finishing | Φ10 (-0.01) | 10,000 | 314 | 0.01875 | 750 | 0.05 (Rough) / 0.02 (Finish) | 4 | 0.07 |
Proven Results & Efficiency
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Flawless Surface Quality
Consistently achieved a highly smooth, chatter-free finish on both the scroll walls and groove bottom, easily surpassing the strict Rz 12.5 requirement.
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Exceptional Dimensional Accuracy
Achieved a 100% pass rate for the complex scroll profile, successfully maintaining the demanding perpendicularity target of < 0.01 mm and the Max 0.12 R-angle.
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Stable Tool Life
The refined cutting edge demonstrated excellent wear resistance, maintaining sharp cutting action and preventing burrs throughout its full targeted lifespan.
Cost Per Part (CPP) Analysis
Lower percentage indicates higher cost-efficiency per part.
Wuxi Sundi Precision Tools Co.,LTD
- +86 18168312921
- +86 18168312921
- +86 18951588639
- info@sundicuttingtools.com
Our team is here to help you! We provide personalized solutions to meet your unique needs. Contact us to learn more.
Sundi's customized finishing tool completely resolved our surface chatter issues on the scroll wraps. The refined edge preparation delivered exceptional profile accuracy and perpendicularity, and the 16.6% reduction in cost-per-part has been a massive win for our compressor production line.
Automotive HVAC Systems Manufacturing Engineer