Accelerating EV Manufacturing with High-Precision Aluminium Battery Fixture Machining
The Challenge
A Tier-2 automotive tooling supplier supporting the UK’s rapidly growing electric vehicle (EV) manufacturing sector required a specialist subcontract partner to produce precision battery module assembly fixtures for a new production line. These fixtures were not vehicle components but production tooling used to accurately position battery modules during automated assembly and quality inspection.
The project presented several manufacturing challenges. The primary fixture body was machined from aerospace-grade aluminium 7075-T6, incorporating complex 3D profiles, deep weight-reduction pockets, multiple datum surfaces, and over 80 precision-drilled mounting locations. Flatness tolerance across the primary locating surface was specified at 0.02 mm, while threaded inserts required perfect positional repeatability to ensure compatibility with robotic assembly equipment.
The customer also faced an aggressive production deadline, leaving little margin for multiple subcontract suppliers. They needed a manufacturing partner capable of consolidating machining, finishing, component marking, and mechanical assembly into a streamlined workflow. Leveraging extensive experience in CNC machining Scotland and precision engineering Dundee, Strategic Innovations developed a manufacturing strategy focused on speed, precision, and process efficiency.
The Engineered Solution
Following a collaborative design-for-manufacture review, our engineering team optimised machining operations to minimise setup changes while maintaining exceptional geometric accuracy.
Each billet underwent initial roughing on our 5-axis CNC milling centres using adaptive high-speed machining strategies that maintained constant cutter engagement throughout deep pocket machining. This significantly reduced tool loading while improving metal removal rates and preserving dimensional stability across the lightweight aluminium structure.
Rather than producing each machined face in separate operations, simultaneous five-axis machining enabled multiple compound angles, locating faces, and complex contours to be completed within a single workholding setup. Consolidating machining operations reduced cumulative tolerance variation while improving consistency between production batches.
Critical dowel locations and precision mounting bores were finish-machined using dedicated probing cycles to verify datum positions before final interpolation. Surface finishing passes utilised fine step-over strategies with balanced carbide tooling, achieving sealing and locating surfaces with consistent Ra 0.6 µm surface roughness.
Several stainless-steel locating pins and threaded alignment bushes supplied within the fixture assembly were produced using CNC sliding head turning, ensuring repeatable dimensional accuracy across hundreds of identical components while significantly reducing cycle time compared with conventional turning methods.
To improve traceability throughout the customer’s manufacturing facility, every fixture received permanent laser marking containing individual serial numbers and batch identification.
The completed project also incorporated comprehensive sub-assembly engineering, where our technicians installed precision bushes, hardened inserts, threaded fasteners, and customer-supplied locator components before carrying out final inspection and packaging. Delivering a fully assembled fixture eliminated secondary assembly work for the customer and enabled immediate integration into their automated production line.
By combining advanced machining capability with integrated finishing and assembly services, Strategic Innovations successfully provided a complete subcontract manufacturing solution from raw material through to production-ready tooling.
The Outcome & Operational Impact
The integrated manufacturing strategy generated measurable operational improvements for the customer.
Project results included:
- 52% reduction in machining setup time through consolidated 5-axis operations.
- 35% faster production lead time by removing multiple external subcontract processes.
- Surface finish consistently achieved Ra 0.6 µm on all critical locating faces.
- Positional tolerances maintained within ±0.01 mm across production batches.
- 22% reduction in overall manufacturing costs through single-source subcontract manufacturing.
- Faster production line commissioning thanks to fully completed assemblies delivered ready for installation.
This project demonstrates how modern subcontract manufacturing UK partners can support rapidly evolving industries through intelligent machining strategies, integrated production services, and practical engineering expertise. By combining 5-axis CNC milling, CNC sliding head turning, precision finishing, and sub-assembly engineering, Strategic Innovations Dundee Ltd helped its customer accelerate production while maintaining exceptional machining quality.
Have a complex engineering component, tooling project, or production bottleneck? Send your technical drawings and RFQ to the engineering team at www.strategic-innovations.co.uk for a comprehensive manufacturing evaluation.
