Shaver Linear Motor Housing

The Challenge

• A 0.5 mm thinnest wall held to a ±0.03–0.05 mm tolerance, with no room for straightening afterwards.
• Full plating coverage with no pitting or blistering. The usual polishing step deforms a wall this thin and pushes the dimensions out of tolerance.
• Threaded holes and through holes that must still pass go/no-go gauges after plating.
• A delivery rate of 5,000 pieces a day or more.

Process Approach

• The thinnest section is 0.5 mm with a tolerance of ±0.03 to 0.05 mm. Gating, overflow and die water cooling were reworked to eliminate cold shuts in the thin wall and uneven shrinkage between thick and thin sections.
• Ejector-pin locking was added to the mould to control the outward distortion of the thin side-core wall as the die opens. Dimensions are held within ±0.02 mm and no straightening is needed before assembly.
• A new polishing sequence on dedicated fixtures solved the deformation that polishing a thin wall normally causes before plating. Plating coverage is now full and even, with no pitting or blistering.
• More than 90% of the holes are formed in the die, which saves cost. Only a small number need secondary CNC work, which raises the Cpk on hole position and improves volume delivery capacity above 5,000 pieces a day.
• The mould was designed with allowance for machining and finishing, and threads are cut with a special tap so M1.5 threads still pass go/no-go gauges after plating.

About Xiuhui

Dongguan Xiuhui Precision Technology Co., Ltd. is based in Houjie, Dongguan, and specialises in precision structural and cosmetic parts in zinc and aluminum alloys. Thin walls, tight tolerances and plated surfaces are the work we take on, and most of our projects start as a casting problem someone else could not solve. Customer size does not decide whether we engage; the engineering does. Customers and industry peers are both welcome to contact us about zinc and aluminum die casting.

Parts cast and finished on the same lines include the Optical Module Housing and the Bluetooth Earphone Front Cover.