Conclusion First (What We Achieved)
In this project, we successfully machined a batch of thin-wall motor housings with:
- Wall thickness: 1.2 mm
- Concentricity: ±0.004–0.005 mm
- Final pass rate: 100%
The key was not just machining, but controlling deformation throughout the entire process.
Project Background
A robotics client approached us with a recurring issue:
Their previous supplier could not maintain bearing alignment after machining and anodizing.
The result:
- Excessive vibration
- Increased noise
- Reduced bearing life
They needed a stable solution for high-speed electric motor housings.
Part Specifications
Material: Aluminum 6061-T6
Wall Thickness: 1.2 mm
Tolerance Requirement: ±0.005 mm (bearing seats)
Quantity: 200 pcs
Application: Robotics motor system
The Engineering Challenges
1. Thin-Wall Deformation
At 1.2 mm thickness, the housing behaves more like a flexible shell than a rigid part.
Key risks:
- Radial clamping deformation
- Vibration during cutting
- Thermal distortion
2. Concentricity Control
The bearing seats on both ends must remain perfectly aligned.
If not:
- Shaft misalignment occurs
- NVH (Noise, Vibration, Harshness) increases
- Product lifespan drops
Why Previous Solutions Failed
Before working with us, the client used a standard machining approach:
- 3-jaw chuck clamping
- Multiple setups
- Conventional finishing
This caused:
- Part deformation during clamping
- Accumulated positioning errors
- Concentricity drift after anodizing
Result:
❗ 35% rejection rate
Our Engineering Solution
1. Custom Clamping Strategy
Instead of standard jaws, we designed:
- 360° wrap-around soft jaws
- Controlled clamping pressure (<2 MPa)
- Even force distribution
This eliminated localized deformation.
2. Single-Setup Machining
All critical features were machined in one setup:
- Bearing bores
- Internal diameters
- Reference surfaces
This prevented:
❗ cumulative positioning errors
3. Stress-Controlled Machining Process
We implemented a staged process:
- Rough machining → stress release
- Thermal stabilization (24h)
- Final precision finishing
This ensured dimensional stability after machining.
4. Precision Boring for Bearing Seats
We used:
- Fine boring tools
- Controlled cutting parameters
- Minimal tool deflection
Result:
- Stable bore geometry
- Consistent concentricity
Final Results
After applying the optimized process:
- Concentricity achieved: ±0.004–0.005 mm
- Pass rate: 100%
- Noise reduction: ~20% (client feedback)
- No deformation after anodizing
Key Takeaways
This project highlights a critical point:
CNC machining thin-wall motor housings is not just about precision cutting —
it is about controlling deformation at every stage.
Start Your Precision CNC Project
If your current supplier is struggling with:
- Thin-wall deformation
- Concentricity issues
- High rejection rates
We can help you solve it with a proven engineering approach.
👉 Upload your CAD file for a quick DFM review.
FAQ
Why is thin-wall motor housing machining difficult?
Because the part easily deforms under clamping and cutting forces.
How do you maintain ±0.005 mm concentricity?
By using single-setup machining and precision boring.
What material is best for motor housings?
6061-T6 aluminum offers the best balance of machinability and stability.
Can anodizing affect precision?
Yes. Without stress control, it can cause dimensional distortion.
