Special Report
“Can a 25 mm Motor Last 10 Years?”
—A Full “Find-Fix-Root-Cause” Story of ASLONG JGA25-310
“Can a 25 mm Motor Last 10 Years?”
—A Full “Find-Fix-Root-Cause” Story of ASLONG JGA25-310
Date: 1 Sept 2025
By: ASLONG Quality & Product Center
By: ASLONG Quality & Product Center
1. Problem Statement – A Customer’s “Challenge Letter”
In March 2024, a major European smart-home brand (code-named H-Home) adopted the JGA25-310 for its new motorized curtain track. After 50 000 units hit the market, field data showed a 0.4 % “intermittent stalling” complaint rate within just six weeks.
Customer’s ultimatum:
Customer’s ultimatum:
“Cases concentrate on high-frequency users (>4 cycles/day). After 6-8 months a 2°-5° dead-zone appears. Provide a permanent fix within 30 days or we switch suppliers.”
2. Problem Definition – 5 Whys in Brief
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Why stalling? → Microscopic debris on the output shaft.
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Why debris? → Grease film breaks down, tooth surfaces scuff.
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Why film breakdown? → Grease flash-point only 80 °C; curtain boxes hit 55 °C in summer.
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Why choose that grease? → Original spec assumed 25 °C lab conditions; extreme use-case matrix missing.
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Why missing matrix? → Scenario validation skipped the “high-temp + high-cycle + side load” combination.
3. Quick Containment – Three Moves in 30 Days
| Action | Lead Time | Result |
|---|---|---|
| High-temp grease swap | 7 days | 120 °C food-grade complex-lithium grease; wear ↓ 92 %. |
| Secondary tooth-profile correction | 10 days | Tip relief 0.015 mm; contact patch ↑ from 40 % to 75 %. |
| 100 % loaded run-in | 13 days | New station: 15 min @ 3 kg·cm; stalling reproduction rate → 0. |
4. Root-Cure – 90-Day “Three-Phase” Validation
Phase 1 – Design
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Magnet upgrade: +12 % flux → +20 % torque margin → lower tooth pressure.
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Bearing evolution: Oil-impregnated bush → 685ZZ ball bearing; axial play 0.08 mm → 0.02 mm.
Phase 2 – Manufacturing
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Vacuum carburizing: Gear surface hardness HRC 58 → 62, wear life × 2.
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In-line SPC: Real-time mesh-noise monitoring; out-of-spec parts auto-locked.
Phase 3 – Validation
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Three-condition matrix (55 °C / 85 % RH / 12 cycles per day) × 1 000 h accelerated test:
Zero failures, zero stalls, grease evaporation < 3 %.
5. Quantified Results
| Metric | Pre-Fix | Post-Fix |
|---|---|---|
| Field return rate | 0.4 % | 0.02 % |
| High-temp 1 000 h wear | 0.04 mm | 0.005 mm |
| Customer follow-up order | Suspended | 3 M units / 3-year locked price |