← Knowledge base · seed/03-drive-train.md

Drive train troubleshooting

Symptoms of a dragging brake

A partially engaged brake produces a recognisable pattern on one wheel side:

• motor current well above the fleet average while driving (E-MOT-502)
• motor temperature climbing steadily over hours until thermal derating (E-MOT-503)
• lower top speed and longer mission durations
• battery drain roughly twice the fleet median
• brake release feedback mismatch warnings (E-MOT-507)

Inspection

1. Take the robot out of service; a dragging brake can overheat the motor winding.

2. With the robot on stands, release the brake from the service menu and rotate the wheel by hand. It should turn freely with no grinding.

3. Measure the brake air gap: nominal 0.3 mm, replace the brake if above 0.5 mm.

4. Check for debris (stretch film, tape) wrapped around the axle.
5. After the fix, run a 30-minute test mission and compare motor current to fleet average.

Battery impact

Increased friction converts battery energy into heat. Abnormal drain usually returns to normal once the mechanical cause is fixed; check the battery state of health only if the drain persists.