Laser Alignment and Readings Repeatability

After taking readings, with a laser alignment system, when making corrections, how often do you have to correct and correct again? Frustration sets in?

Precision alignment with a laser system should take no more than two corrections. However, to achieve this end, several things should be checked before starting the work.

Are you one of those who encounter some repeatability issues? Or needing several corrections? Do you think your laser system is not working as it should?

Here are important points to check to help you with the task at hand;

Ambient vibration (environment); you can adjust the acquisition time with most of the laser system on the market. With ambient vibration detect in the area, you should adjust to a longer acquisition time, so it doesn’t affect your alignment results.
Cleanliness of laser and receptor filters; always do a verification of your laser and receptor filters before starting the alignment. Dirty filters can distort the results. Cleaning technique: 1) Clean off dirt with air can. 2) Get a Q-tip and tip one side in isopropyl alcohol and clean 1 shot. 3) Wipe off alcohol with other side of Q-tip and make sure it is all clean.
Soft foot; soft foot verification is essential to results repeatability. You can use either the application in your laser alignment system, runout probe, (dial indicator) or a shim (each corner of each foot). Whatever the technique, it is important to ensure that no angular and short foot is present under each foot, if not corrected, it could cause a vibration residual.
Mechanical Looseness (bearing); Your results will never repeat if one of the bearing as an excessive clearance, caused by wear. You will need to replace the bearing before carrying on.
Backlash (coupling); the non-repeatability of the degrees between each head can result in false readings. Always keep the coupling in the same direction and if possible, rotate in the same direction as the equipment. Do not have over 0.5 degrees between each head at every measurement.
Non-rigid base; unfortunately, this is often out of your control. If you have a non-rigid base, it will be impossible to get a precision alignment results. The equipment will move between each correction and tightening.

These are some points to consider during your next precision alignment. Always remember, work well and slowly, to work quicker.