As alignment professionals we all want to do the right thing and perform the best shaft alignment possible; however there may be a time when you have to choose and knowingly leave a machine slightly misaligned for the short-term until other corrections can be made to the equipment to get it to an “alignable” condition.
For example; while performing a Verti-Zontal Compound MoveTM on a motor pump set, during the OJT portion of a Fixturlaser XA Pro training class, the mechanics found the motor to be bolt-bound when making the live horizontal adjustment. The FeetLock Function of the XA was used to easily correct the bolt-bound condition with a small adjustment to the motor and pump.
Prior to that, the class found the motor was just “slightly” bolt-bound. They could adjust the rear feet to get the horizontal angularity in tolerance but the offset was slightly out of tolerance.
Conversely by adjusting the motor’s front feet they were able to get the horizontal offset in tolerance but the angularity was then slightly out of tolerance.
After several failed attempts to get both the angular and offset coupling values in tolerance, via only adjusting the motor, the FeetLock Function was utilized as previously stated.
This however let to the question: What if, at this point in time, you could not move the pump and had to leave the machines slightly misaligned until other corrections can be made to get the equipment into an “alignable” condition. What would you choose? Slight angular misalignment or slight offset misalignment?
So dear VibrAligners, we would love to hear your comments as to which condition you would choose and your reasons for doing so.
5 Comments
For me, it would depend on the coupling type, but most flexible couplings are more tolerant of a slight angular misalignment than they are of offset misalignment. In your example, I would probably choose to leave it out angularly.
Excellent topic! Anyone else?
Good information
I agree with Stan…on both counts.
When machinery is misaligned or unbalanced it causes increased energy usage. This leads to increased costs for running the equipment as well as decreased life span of the equipment itself. Today, most maintenance personnel rely on compound alignment techniques, which allow them to adjust shafts along both planes at the same time.
I would go for Slight offset misalignment if it is a tire type coupling
I would go for slight angular misalignment if it has a less flexible type coupling.
Really like your articles always learn loads