Buying Stator and Rotor Core Sets: How to Control Matched Drawing Revisions

When buying stator and rotor core sets, approve the two components as one documented configuration—not as two unrelated part numbers. Identify the permitted drawing revision for each component, record their assembly relationship, and connect sample approval, inspection records and shipment labels to that combination.

The revision letters do not have to match. What matters is whether the specific stator revision and rotor revision have been reviewed and released for use together.

Why individual part approval is not enough

A stator core may meet its own drawing while a rotor core meets another drawing, yet the combination may not represent the motor configuration the buyer intended to approve.

This can happen when one drawing changes while the other remains unchanged, or when purchasing orders refer to individual components without identifying the approved pairing.

The practical solution is a set-level configuration record. It should connect the motor platform, stator part number, rotor part number, drawing revisions and required delivery formats.

That record does not replace either component drawing. It tells everyone which drawings belong together.

Create a configuration record before sample release

A useful record should answer four questions:

1. Which stator and rotor drawings define this set?
2. Which assembly drawing or interface specification governs their relationship?
3. What sample evidence supports approval?
4. Which configuration is authorized for repeat orders?

Identify the interface requirements

The motor designer should identify the relationships that require coordinated review. Depending on the design, these may include stator bore, rotor outside diameter, axial alignment, stack lengths and locating features.

Avoid asking the lamination supplier to infer the complete assembled air gap from two nominal diameters alone. Shaft, bearing, housing and assembly variation may also affect the finished motor. The buyer should define the relevant interface requirements and who is responsible for verifying them.

Separate part conformity from motor validation

A dimensional report shows whether measured characteristics meet the agreed component requirements. It does not, by itself, demonstrate that the assembled motor meets its operating targets.

Specify which checks belong to the core supplier and which remain with the motor manufacturer. This distinction helps prevent sample approval from being interpreted more broadly than the evidence supports.

Review changes at the set level

A change to one component should trigger a review of its effect on the approved pair. It does not automatically mean both components need modification.

For example, a revised stator feature may leave the rotor geometry unchanged. The change record should still state whether the existing rotor revision remains approved.

Record the decision rather than relying on an email subject line such as “latest drawing.”

Define the production cut-in point

For an approved change, establish when the new configuration becomes effective. Use an identifiable purchase order, production lot or other agreed reference.

Also decide how to handle:

• Existing finished cores.
• Work in progress.
• Previously approved samples.
• Open orders using the earlier configuration.

Where old and new configurations are not interchangeable, their separation should be explicit.

Make inspection and packaging support the approved pairing

Inspection records should identify the component part number and drawing revision. Where buyers require a set-level review, the approval package should reference both reports.

Packaging should make the delivered configuration recognizable without assuming that every stator must be physically packed beside one rotor.

Some projects may require paired packs. Others may use separate cartons with clear configuration identification. The right approach depends on the buyer’s assembly and receiving process.

Define the permitted quantities, labels and mixing rules before shipment.

Buyer checklist for matched core sets

Before releasing a purchase order, confirm:

• Both component part numbers and drawing revisions are listed.
• The approved stator–rotor combination is recorded.
• Interface requirements and validation responsibilities are clear.
• Delivery format is defined for each component.
• Sample approval identifies the configuration reviewed.
• Drawing changes have an approval and cut-in process.
• Inspection reports reference the correct revisions.
• Labels and packing instructions prevent unintended mixing.

Start with the complete configuration

For a coordinated sourcing discussion, review the stator and rotor core sets product page and the published manufacturing capabilities.

If the project also needs dimensional acceptance planning, use the motor lamination tolerance guide as a separate reference.

Start an RFQ with both drawings, the intended revision pairing, delivery formats and estimated quantities. Feasibility, inspection scope and commercial terms require project-specific confirmation.