customization case
Successful Customized Non-Standard Bearing Projects For Global Equipment Manufacturers
Custom Non-Standard Miniature Precision Bearings for a Local Micro-Motor Manufacturer — A Full Case Study
Introduction — When Standard Bearings Are Not Enough
For every manufacturer of micro-motor products, the quality of the rotating assembly is the single most decisive factor between a reliable product and a field failure. At the heart of that assembly sit two small but critical parts: the motor shaft bushing and the end cap bearing seat. These components must locate the shaft precisely, support radial and axial loads, resist wear under continuous rotation, and hold a concentricity that often measures in micrometers. Yet for a growing number of applications, standard off-the-shelf bearings simply cannot deliver.
This case study presents a complete, real-world example: a micro-motor manufacturer located in our own local district — literally on the same street as our facility — came to Jakstar Bearing with a recurring problem in its motor shaft bushing and end cap bearing seat assemblies. Through non-standard custom miniature precision bearings, we were able to eliminate premature failure, stabilize dimensional consistency, and secure a long-term production partnership.
Background — About the Customer
The customer is a well-established micro-motor manufacturer based in our local area (Wuxi, Jiangsu, China), producing small DC motors and brushless motors for household appliances, small pumps, automotive auxiliary devices, and light industrial equipment. Like many manufacturers in this segment, they operate on tight margins and extremely high quality expectations: one rejected batch can delay an entire assembly line.
For years, the customer sourced standard miniature bearings from multiple suppliers. Because their motors are customized for different OEM clients, however, the shaft and end cap designs vary from order to order. Standard bearing sizes did not always match the required dimensions, and where they did match, the tolerance and precision levels were inconsistent across batches. This inconsistency became a chronic source of returns, rework, and — worst of all — reputation damage with their own OEM customers.
The Challenge — Why Standard Bearings Failed
The customer raised three specific problems, all centered on the motor shaft bushing and end cap bearing seat:
1. Dimensional Mismatch on the Shaft BushingThe motor shaft bushing must sit tightly on the shaft while rotating smoothly inside the housing. In several new motor models, the shaft diameter did not correspond to any standard bearing bore. Forcing a standard bearing onto a non-standard shaft created excessive preload, overheating, and premature noise.
2. Concentricity Failure on the End Cap Bearing SeatThe end cap bearing seat requires the bearing bore and the outer seat to be perfectly concentric — in our customer's case, within 0.005 mm. Standard bearings supplied by their previous vendors showed run-out beyond the allowed limit, causing vibration and eccentric rotation that shortened motor life dramatically.
3. Inconsistent Heat Treatment and HardnessFor motor shaft bushing applications, the component material must combine wear resistance with dimensional stability. The customer's standard bearings varied in hardness (RC 52–56) and surface finish between batches, making assembly tolerances unpredictable.
In short, the customer needed more than a bearing — they needed non-standard custom precision components engineered to match their exact motor geometry, delivered with repeatable quality and full inspection documentation.
Our Solution — Non-Standard Custom Miniature Precision Bearings
After a detailed review of the customer's drawings, sample shafts, and end cap bearing seat specifications, our engineering team proposed a complete non-standard custom solution. Here is what we delivered.
Custom Dimensional Engineering
We manufactured the motor shaft bushing and end cap bearing seat components to the customer's exact drawings, covering dimensions that fall outside standard miniature bearing ranges. This included:
Custom bore sizes matched precisely to the customer's non-standard shaft diameters;
Custom outer diameters fitted to the end cap bearing seat housings;
Controlled clearances (C2–C4) selected per the specific running conditions;
Custom widths and chamfers to match assembly fixtures.
Because we produce across the 60, 62, 63, 67, 68 and 69 series, and are equally comfortable producing non-standard bores within 30 mm, we could cover the customer's full range of micro-motor sizes from one single supplier.
Precision, Materials, and Heat Treatment
For this non-standard custom project, we specified SUJ2 bearing steel (GCr15) — the industry-standard high-carbon chromium steel for precision bearings — with heat treatment to RC 52–56. This gave the motor shaft bushing the hardness to resist wear over long duty cycles while maintaining dimensional stability through the grinding and lapping processes.
H3: Micro-Level Tolerances and Full Inspection
The most demanding requirement was concentricity of 0.005 mm. Our process controls achieved this through:
Precision grinding of both bore and outer surfaces;
Lapping of critical chamfers and contact faces;
100% full inspection of dimensional, concentricity, and surface finish parameters;
Random sampling inspection on every batch as an additional layer of assurance.
Every batch shipped with a complete inspection report, giving the customer auditable proof of quality — a level of documentation their previous suppliers could not provide.
Implementation — From Prototype to Stable Production
We followed a phased approach to de-risk the customer's switch to non-standard custom miniature precision bearings:
Drawing & Sample Review — We verified every critical dimension, including bore tolerance, outer diameter tolerance, height, chamfer angles, and concentricity.
Prototype Sampling — A small batch of samples was produced and tested by the customer on real motors. This validated the end cap bearing seat fit and shaft bushing performance under load.
Small-Batch Trial Order — Once samples passed, we delivered a small production batch (matching the customer's 320-piece order size) with full inspection reports.
Scale-up & Repeat Supply — After three consecutive on-time, defect-free batches, the customer moved us to recurring supply status.
The customer's engineers particularly valued that we could adjust the design on request — changing clearances, chamfers, or materials quickly as their OEM orders evolved. This flexibility in non-standard custom work is exactly where a dedicated miniature bearing specialist outperforms a generalist bearing trader
Results — Measurable ImprovementsThe switch to our custom miniature precision bearings produced clear, quantifiable results for the micro-motor manufacturer:
| Improvement Area | Result |
| Premature bearing failure | Eliminated — no field returns in the first two production quarters |
| Vibration / eccentric rotation | Resolved via 0.005 mm concentricity control on the end cap bearing seat |
| Dimensional consistency | 100% within drawing tolerance across all batches |
| Assembly rejection rate | Reduced significantly due to uniform shaft bushing fit |
| Supplier management | Consolidated to a single reliable supplier for all miniature sizes |
| Long-term partnership |
For a micro-motor producer, every percentage point of reduced rejection translates directly into profit margin. By stabilizing the motor shaft bushing and end cap bearing seat assemblies, we helped the customer protect both their margins and their reputation with OEM clients.
Customer's WordsJakstar understood our problem from the first call. Our shaft bushing and end cap bearing seat had been our biggest quality headache for two years, and the non-standard custom approach fixed it in one project. The 0.005 mm concentricity is consistently held, the documentation is complete, and delivery is always on time. They are now our trusted partner for precision miniature bearings
Why Jakstar Bearing for Non-Standard Custom Miniature Bearings?This case is not an exception — it is our standard way of working. Choose us for custom miniature precision bearings because:
Series Coverage: 60, 62, 63, 67, 68, 69 series plus non-standard bores within 30 mm;
Custom Engineering: dimensions, tolerance, material, and lubricant made to your drawing or sample;
Micro-Level Precision: concentricity to 0.005 mm, precision grinding and lapping;
Full Documentation: inspection report with every batch, 100% full inspection plus random sampling;
Flexible Batches: from prototype sampling to stable recurring supply;
Local Advantage: as a supplier located in the same region, we offer fast communication, short lead times, and easy on-site visits.Conclusion — Custom Non-Standard Bearings Are the Reliable Path
The takeaway is simple: for micro-motor applications, the motor shaft bushing and end cap bearing seat demand a level of precision that standard bearings often cannot provide. Non-standard custom miniature precision bearings — engineered to exact drawings, held to micrometer tolerances, and backed by full inspection — are the dependable solution.Jakstar Bearing helped a local micro-motor manufacturer transform a chronic quality problem into a stable, long-term supply relationship. If your production faces similar challenges with motor shaft bushing, end cap bearing seat, or any custom rotating component, we would welcome your drawings for a free evaluation.
Contact Jakstar Bearing
Ready to discuss your non-standard custom miniature precision bearings project? Send us your drawings or samples for a quotation, or schedule a visit to our facility. We serve customers worldwide and look forward to working with you.Jakstar Bearing — Precision Miniature Bearings, Custom-Made to Your Needs.
