Establishing a laser shaft alignment programme
A laser shaft alignment programme is a standardised regime for aligning coupled rotating machines — motors to pumps, fans or gearboxes — using laser-detector tools rather than straightedges or dial gauges. It sets alignment tolerances by speed, records every job, and treats precision alignment as a routine reliability task rather than an occasional fix.
What it is
Shaft alignment corrects the offset and angularity between the shafts of two coupled machines so they rotate on a common centreline. A programme formalises this: it specifies the laser tools used, the tolerance bands applied at different running speeds, soft-foot and thermal-growth correction, and the documentation kept for each machine. It turns alignment from a craft skill exercised inconsistently into a repeatable, auditable practice.
Why it is done
Misalignment is one of the largest contributors to premature bearing and seal failure on rotating equipment, and it also raises vibration and absorbed power. Dial-gauge methods are slow and error-prone, so misalignment often goes uncorrected or is checked only roughly. A laser programme makes precise alignment fast enough to do every time a coupling is broken, extending bearing and seal life and cutting repeat failures.
How it is done
Machines are catalogued and assigned tolerance classes based on running speed, with tighter limits at higher speeds. Before alignment, soft foot is checked and corrected so the machine sits flat, and thermal-growth targets are applied where hot running shifts the centreline. The laser tool measures offset and angularity in both planes, and shims and lateral moves are made until the readings fall inside tolerance. Each completed job is recorded with its final figures so trends and recurring problems are visible.
- Set tolerance classes
- Check soft foot
- Apply thermal targets
- Laser measure offset
- Shim and move
- Record results
What to watch for
The frequent failures are ignoring soft foot, which makes the machine impossible to align repeatably, and aligning cold without correcting for thermal growth so the machine runs misaligned once hot. Treating alignment as a one-off rather than checking it after any coupling work also lets misalignment creep back in unnoticed.
Related practices
Transitioning to condition-based maintenance
Rolling out reliability-centred maintenance
Running an asset criticality ranking exercise
Related topics
Vibration Analysis · Condition Monitoring · MTBF (Mean Time Between Failures)
Common in: Food Processing · Chemicals · Power Generation · Paper & Packaging · Cement