What play must be eliminated before performing laser alignment?

In the context of laser alignment, eliminating torsional flexibility is crucial because this type of play can introduce significant inaccuracies in the alignment process. Torsional play refers to the rotational movement that occurs in shafts or couplings under load. If there is any give or flexibility present in the system, it can lead to misalignment when the machinery is in operation, as the shafts may not maintain the intended alignment under different operational conditions.

Effective laser alignment requires a rigid connection between the components being aligned to ensure that they operate true to their intended axis. If torsional flexibility is present, it could cause the laser readings to fluctuate, resulting in a misalignment that is not reflective of the actual operational state of the machine. Therefore, addressing and eliminating this aspect helps ensure a more precise and durable alignment.