Flywheel Fabrication in Vietnam

Overview of the Flywheel Fabrication Project

This Flywheel Fabrication case study presents how Vietnam Outsourcing (VNO) helped a UK-based company in the woodworking machinery industry find a new and more reliable supplier outside China.

The product, a Square Flywheel, required complex and multi-stage fabrication involving laser cutting, CNC machining, welding, dynamic balancing, and coating. Each process demanded high precision and strict control of dimensional tolerances.

VNO collaborated with a specialized Vietnamese supplier that already produced industrial fans, wing-shaped components, and flywheels—all requiring a closed production cycle. Together, we developed an efficient and repeatable workflow that ensured consistent product quality for international export.

Flywheel Fabrication Process

Step 1 - Laser cut

First, raw steel materials were laser-cut according to the engineering drawing, ensuring accuracy for subsequent machining stages.

Step 2 - CNC machining

Then, CNC machining refined the surface finish and achieved tight dimensional tolerances essential for the flywheel’s balance and stability.

Step 3 - Welding

After that, subcomponents were welded together using controlled heat input to maintain structural integrity.

Step 4 – CNC Machining (Post-Weld)

Once welding was completed, another CNC machining step ensured precise alignment and corrected minor deformations.

Step 5 – Dynamic Balancing

Next, each flywheel was tested and adjusted through a dynamic balancing process to eliminate vibration during high-speed rotation.

Step 6 – Coating

Finally, the surface was coated to protect the flywheel from corrosion and wear, extending its lifespan under continuous industrial use.

Challenges in Flywheel Fabrication

Heat distortion

Details involved large quantity of welding, heat distortion is quite a problem

High speed rotation

Dynamic balancing process for high speed rotating heavy components

Complicated technique involved

The product is a wood cutter in a high-speed rotary wood crusher (also a flywheel), thin-walled structure with large weight and size, complicated production technology.
Laser cutting to create molds, CNC machining, lots of welds to join the sub-parts firmly, CNC machining, and dynamic balancing and painting.

VNO’s Solutions and Engineering Support

To address these challenges, VNO implemented several process improvements and collaborated closely with both local and international engineering teams.

Heat Control and Deformation Prevention:
We applied pre-weld temperature compensation, used anti-deformation jigs, and introduced natural cooling and flattening stages after welding.

Advanced CNC Machining Setup:
The project required 5-axis milling or customized jigs to achieve perfect dimensional accuracy. VNO coordinated machine setup, test runs, and fixture design to optimize production.

Cross-Border Engineering Collaboration:
Throughout product development, VNO’s Vietnam and China-based engineers worked side-by-side with supplier teams. Every sample went through multiple inspection rounds and was approved by the UK QA Manager before shipment.

Summary

After optimization, the flywheel fabrication process achieved a 100% approval rate in the first production run, confirming process stability and repeatability.

Before and after comparision

Duration

4 month

Number of samples

Sample pass

1st Production (before)

Duration

1 month

Number of samples

Sample pass

2nd Production (after)

“This project is rather challenging, because this product can be considered new to the company. However, working with Vietnam Outsourcing give us the determination to accept this challenges. It is also an opportunity for us to improve our process and advance to a higher level of product quality.”

Mr. Kha – Chairman