How to improve the assembly efficiency and quality of electric scooters
A moving assembly line boosts e-scooter productivity and quality by splitting the vehicle into short, standardized, error-proofed stations. One-time fixture and AGV pull cut handling 90 % and line-side inventory to 4 h; parallel sub-assembly balances work at 93 % and halves takt to 45 s. Servo spindles with real-time torque curves lift first-time yield to 99.5 %; mid-line hi-pot, leak and CAN tests slash early field failures from 1 500 ppm to 380 ppm. Blockchain traceability recalls lots in 30 min. The result: 800 units per shift, 99.5 % FTY, scalable, data-driven mass production.
- Six levers for higher efficiency
1) Takt-time compression: 30 min → 45 s
An 80-m smart e-scooter line (East-China site, 23 stations) now runs at 45 s takt, giving 800 units/day. Line length is 40 % shorter and head-count 28 % lower for the same output.
2) One-time fixture, zero re-handling
A patented “skid + friction-roller” conveyor keeps the frame located once. It passes six module stations (motor, battery, controller, wheels, brake, lighting) with no re-lift. Internal transport per unit drops from 260 m to 18 m and logistic share of cycle time from 12 % to 2 %.
3) Parallel sub-assembly, shortest main line
Hub-motor pre-assembly runs in parallel: bearings, stator heat-shrinking and end-cover tightening are finished in 35 s; the main line only adds two flange bolts in 42 s. Line balance reaches 93 % and OEE 85 % vs. 65 % industry average.
4) Error-proof tightening, FTY 99.5 %
120 electric servo spindles upload torque-angle curves to MES in real time; any out-of-spec event stops the line. First-time yield rises from 97.2 % to 99.5 % and rework stations fall from six to one.
5) Smart logistics, 4 h on-line inventory
AGVs + e-Kanban deliver large parts every 2 h and small parts every 4 h instead of the usual 1.5 days. A 30 000 m² plant cancelled two rented warehouses, saving CNY 2.4 M/year in rent.
6) Mixed-model flexibility, 0 min change-over
RFID identifies the model automatically; conveyor width, fixture height and program parameters switch on the fly. Three scooter variants can be mixed with 0 min downtime and 92 % capacity utilisation, 18 points above a dedicated line.
- Five quality gates
Gate 1 – Incoming material block
A “key-component smart gate” at line entrance 100 % scans battery packs (BMS version, cycle-life record) and hub motors (hi-pot & leak-test report). Non-conforming parts are automatically diverted, ensuring defect-free launch.
Gate 2 – In-process error proofing
Electronic work instructions on 32-inch screens plus infra-red part counters: any extra or missing pick triggers an immediate alarm. Result: zero stop for wrong-part fitting in 12 months vs. 3.8/month on the legacy line.
Gate 3 – 200 % torque control
Class-A bolts (wheel, motor, suspension) are tightened by a servo spindle and immediately re-tightened by a second data-collecting spindle; if the two torque-angle curves differ by >3 % the unit is locked. Zero field claims related to torque have been reported for 11 consecutive months.
Gate 4 – In-line testing replaces off-line sampling
A mid-line “3-in-1 test island” performs:
- Hi-pot 800 V/20 mA, 2 s
- Air-leak 30 kPa, 15 s, ΔP <50 Pa
- Full-vehicle CAN handshake, 120 signals
All results are VIN-linked and cloud-stored; 80 % of type-approval tests are completed on every unit. Early-life field failures dropped from 1 500 ppm to 380 ppm.
Gate 5 – End-to-end traceability
A “one-vehicle-one-dossier” system writes 160 critical part numbers, supplier lots, operator IDs, equipment IDs and ambient data into a blockchain ledger. Market issues are traced to lot level in 15 min and affected vehicles locked in 30 min, cutting recall cost by 60 %.
- Reference sites
| Region | Site profile | Key line features | Annual cap. | Benchmark results |
|---|---|---|---|---|
| East-China | Smart e-scooter plant | 45 s takt, 3-in-1 test island, AGV pull | 600 k | 92 % OEE, 380 ppm early failures |
| South-China | Export scooter hub | 6 mixed lines, imported test equipment, modular design | 500 k | 12 test devices, exports to 60 countries |
| Central-China | E-moto integrated plant | Blockchain traceability, CMM, chassis-dyno emission | 1 M | 400 ppm early failures |
| Tai-Cang (Yangtze Delta) | High-automation site | Poka-yoke build, 0.2 mm bearing press, double-torque | 300 k | 99.5 % FTY, 85 % OEE |
- Take-away
By turning “whole-vehicle” work into repeatable, data-driven and error-proofed stations, the moving line delivers measurable, scalable gains: 45-second takt, 99.5 % first-time yield and early-life failure rates below 400 ppm. These are the systemic benefits that continuous-flow assembly brings to high-volume e-scooter production.