Misalignment rarely announces itself directly — it shows up disguised as a coupling replaced too often, a bearing that never quite lasts its rated life, or a seal that keeps weeping. An annual laser alignment check on every motor-pump and motor-fan set catches the root cause before it gets blamed on the wrong component. Here is what that check should actually cover.
The Real Cost Of "Good Enough"
A shaft that's within a millimetre by eye can still be badly out of tolerance for a laser system. That gap quietly consumes bearing life, seal life, and energy through every hour the machine runs — costs that never show up on the alignment line item.
Three Checks Before The Laser Even Comes Out
Skipping these makes every reading after them unreliable.
Soft Foot
Checked at each mounting bolt before touching alignment — a soft foot moves the whole result once torqued down.
Baseplate Condition
Cracked grout or a warped baseplate makes any alignment temporary, however accurate the reading was today.
Coupling Condition
Worn elements or damaged coupling faces can mask a true reading or introduce vibration of their own.
Cold Reading vs Thermal Growth
| Stage |
What's Measured |
Why It Matters |
| Cold alignment |
Shaft position at ambient temperature |
The starting point every calculation builds from |
| Thermal growth offset |
Expected shaft rise once at running temperature |
Corrects the cold target so it's aligned once hot |
| Hot check (if fitted) |
Actual running-temperature position |
Confirms the offset calculation was correct |
Tolerance Bands By Speed
Under 1000 RPM
Loosest band — still worth doing right, since low speed doesn't mean low downtime cost.
1000–3000 RPM
Where most plant motor-pump and motor-fan sets sit. Tolerances tighten noticeably here.
Above 3000 RPM
Tightest tolerance band — small offsets translate into large forces at these speeds.
A one-off alignment printout gets filed and forgotten until the next failure. Teams that sign up for Oxmaint attach every alignment report to the asset's history, so the next technician can see what tolerance band it was set to and when it's due again — or book a demo to see the alignment record workflow live.
Q
Is annual alignment enough, or only after a coupling change?
Both. The annual check catches drift from baseplate settling or foundation movement that happens even without any work on the machine, while any coupling replacement or motor swap should always trigger its own alignment check.
Q
Why does soft foot get checked before alignment, not after?
Because torquing down a machine with a soft foot physically twists the frame, moving the shaft position. Any alignment done first is invalidated the moment the soft foot is corrected afterward.
Q
Does every machine need a thermal growth offset applied?
Only ones with a meaningful temperature rise between shutdown and running condition, such as many pumps and larger motors. Smaller, low-thermal-rise equipment often aligns fine to the cold target alone.
Keep Every Alignment Report On The Asset, Not In A Drawer
Soft foot checks, tolerance bands, and thermal growth offsets logged against each motor-pump and motor-fan set, with the next due date tracked automatically. Sign up for a free trial to set up your first rotating asset record, or book a demo to see the alignment history view live.
