The start and stop of overhead cranes are resolved through the conflict between the active wheel and the I-beam's trajectory. If there is any discrepancy in the conflicting forces at the active wheels of the crane's main beams on both ends, the crane will eventually develop a twisting swing. Below, we analyze the causes and solutions for different swing conditions.

No wobble at start-up, wobble during interruption:

When there is no significant oscillation during startup but there is during stopping, if the active wheel on the oscillating side follows the oscillation, it can be determined that the cause is uneven braking on both sides. During startup, the motor operates simultaneously, thus no oscillation is displayed. If the active wheel does not rotate with the oscillation, it is not a braking issue; it is simply caused by one side of the active wheel being suspended in the air.

Swing Continues Despite Possible Hiccups in Launch

Twist and oscillation at startup and shutdown typically occur in two scenarios: one side with a motor failure and ineffective braking; or one side with a conflicting force on the active wheel of the end beam, which may be suspended in the air. For the motor failure and ineffective braking situation, a solution can be obtained by listening to opinions and replacing or adjusting the motor, as well as regulating the braking.

There are mainly two types of torsional oscillations during startup and interruption caused by the active wheel suspended in the air:

Due to the uneven height of the flanges on the I-beam's lower web, the I-beam's movement path tread cannot effectively touch the active wheel of the end beam.

The issue lies in the inherent deviation of the I-beam. If the side with excessive deviation is where the active wheel operates, it can lead to poor contact between the active wheel and the running surface of the I-beam's trajectory. In either case, due to the active wheel's inability to make proper contact with the I-beam's running surface during startup, the wheel may roll over but cannot effectively move, resulting in a lag.

As the side that had drifted a certain distance moves forward, it is propelled by the other side. Upon the side coming to a stop, although the active wheel on the side that drifted has stopped rolling, the active wheel that actually creates the braking effect and the I-beam's moving track surface do not meet optimally, resulting in insufficient frictional force. Under the actual effect of inertia, it continues to move forward and will still exhibit oscillation.