How a 434 mm Precision Sleeve With 0.02 mm Concentricity Moved From Drawing to Production
A customer needed a 434 mm long sleeve with an Ø11 mm outside diameter, Ø5 mm inside diameter and 0.02 mm concentricity requirement. Manufacturing the component as one long piece while maintaining the required relationship between the inner and outer features presented a practical manufacturing challenge.
After reviewing the requirement with the customer, a two-piece manufacturing approach was proposed. The sections were manufactured separately and then precision assembled. Prototype verification confirmed the required dimensions and concentricity range, followed by customer use testing and a formal order for 20,000 sets.
The Drawing Requirement
The project began with a customer drawing for a long precision sleeve.
The key dimensional requirements included:
- 434 mm overall length
- Ø11 mm outside diameter
- Ø5 mm inside diameter
- 0.02 mm concentricity requirement between the relevant inner and outer features
Individually, these values describe the required component.
The manufacturing challenge appeared when they had to be achieved together on the same long, slender part.
The Manufacturing Challenge
The Difficulty Came From the Combination of Geometry and Precision
The main challenge was not simply producing an Ø11 mm outside diameter or an Ø5 mm inside diameter.
The component was 434 mm long while only Ø11 mm in outside diameter, and the required relationship between the inner and outer features had to remain within the specified concentricity range.
Manufacturing the sleeve as one long component while maintaining that relationship was difficult with the available manufacturing approach.
This created an important question before production:
Rather than proceeding directly into production, the manufacturing approach was reviewed with the customer.
Manufacturing Review
Review the Required Result, Not Only the Original Manufacturing Route
The drawing defined the result the component needed to achieve.
The next step was to determine a practical way to manufacture and verify that result.
After discussion with the customer, a two-piece approach was proposed.
The purpose of the proposal was not to change the functional requirement.
The objective was to find another manufacturing path capable of achieving the required relationship between the features after assembly.
The customer agreed to evaluate the approach through prototype testing before moving forward.
Prototype & Verification
The Manufacturing Approach Was Evaluated Through Sampling
A prototype was produced using the agreed two-piece approach.
During prototype evaluation:
- the required dimensions were within range;
- the assembled sleeve met the required concentricity range; and
- the mating relationship between the relevant features was controlled during assembly.
This prototype stage was important because the proposed manufacturing approach needed to demonstrate that the assembled component could still achieve the required result in practice.
The customer then evaluated the component in use.
Project Result
From Manufacturing Review to a 20,000-Set Order
After customer use testing, the component performed as expected for the customer's production requirement.
Drawing Requirement
Manufacturing Challenge Identified
Manufacturing Review
Two-Piece Approach
Prototype Verification
Customer Use Test
20,000-Set Production Order
What This Case Demonstrates
This case does not mean that long precision sleeves should generally be divided into multiple sections.
That is not the lesson.
The important point is that a completed drawing defines the required engineering result, while the practical manufacturing route may still need to be evaluated.
In this project, the interaction between:
created a manufacturing challenge that was not useful to treat as four isolated specifications.
They had to be considered together.
The drawing remained the definition of what the component needed to achieve.
Manufacturing review helped determine how that requirement could be translated into a practical component.
When a Similar Review May Be Useful
Not every drawing-based component requires this level of manufacturing discussion.
A review becomes more useful when a component combines factors such as:
The objective is not to redesign components unnecessarily.
It is to identify manufacturing considerations early enough to discuss them before they become production problems.
Frequently Asked Questions
Why was the sleeve not manufactured as one long component?
The combination of the 434 mm length, Ø11 mm outside diameter, Ø5 mm inside diameter and 0.02 mm concentricity requirement made the one-piece approach difficult with the available manufacturing approach. A two-piece solution was therefore discussed with the customer and evaluated through sampling.
Did the two-piece approach change the required concentricity?
No. The purpose of the manufacturing review was to find a practical way to achieve the required result. The assembled prototype was verified against the required concentricity range.
How was the proposed approach validated?
A prototype was produced and evaluated. The dimensions were within the required range, the assembled sleeve met the required concentricity range, and the mating relationship between the relevant features was controlled during assembly. The customer subsequently tested the component in use.
What happened after prototype testing?
After customer use testing, the component met the customer's production expectation and a formal order for 20,000 sets followed.
Does Gorgeo always recommend changing a drawing when manufacturing is difficult?
No. Manufacturing review does not automatically mean changing a customer's design. The purpose is to understand the engineering requirement and determine whether the intended manufacturing approach can achieve it reliably. If another approach may be useful, it can be discussed and validated with the customer before production.
Have a Drawing With Challenging Geometry or Tolerances?
If a drawing is moving toward prototype or production, manufacturing review can help identify how geometry, tolerances, critical fits and verification requirements interact with the manufacturing approach.
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