Condition Monitoring Expert Tip #10 by Mobius Institute
No, sadly, that is not right. Unless the person has been properly trained, unless the company has specified precision alignment tolerances, and unless the training is followed and the tolerances are achieved, then you are not performing precision alignment.

We see this as a very common problem. Laser alignment systems can achieve terrific results. And a precision-aligned machine is far more reliable than a machine that has been “roughly” aligned with an alignment system, and far superior to a machine aligned with a straight edge. But if your maintenance technicians do not appreciate why that last shim should be installed, and why the motor must be moved such a small amount to the left or right, then those corrections will not be made – and yes, it does matter.

Research by Tedric A. Harris, in the book “Rolling Element Bearing Analysis” (John Wiley & Sons), showed that just 5 minutes (5/60 of a degree) of angular misalignment can reduce the life of a bearing by half. Yes, precision matters!