November 7, 2017
What is the Fixturlaser NXA Runout Probe?
By Stan Riddle
Acoem USA has introduced the Runout Probe, an accessory device for the NXA Pro. I (as a jaded, grizzled old millwright-but a good “company man”) was outwardly excited. But inside, I thought, what’s the big deal? It’s an electronic dial indicator.
That’s what I thought – until I took it for a test drive! I taught an alignment class for a large compressor manufacturer, and brought one to show the class, and to try it out.
What is it good for? As it turns out, quite a lot!
At the company where I was training, one of their pre-alignment procedures is to check coupling concentricity and runout – and document it. With the run out probe, you can save it, document it, and print the results.
- Check gearbox thrust? Doable, and documentable, with the run out probe.
- Check soft foot on the compressor, gearbox, and motor, at the shafts? The run out probe can do that too!
- Check run out of the coupling spool piece? The run out probe can handle it.
- Loosen flanges, and check for pipe strain influence at the shafts? Yes, it can.
- Measure soft foot at the foot? Can do.
Is there more? I’m glad you asked!
- Check for a loose pump base. Mount the probe magnetic base to the pump base, and zero the indicator on the floor. Pry on the base, or step on it, to see if there’s movement.
- Perform a lift check, to check for excessive bearing clearance. Zero the probe on the shaft, close to the bearing, and gently lift the shaft with a pry bar.
- Measure a shim, especially one that is unmarked, or hand cut, to determine its thickness.
- Measure for thermal and dynamic changes on piping, bases, or other structures.
- Check runout (bend) on a piston rod, crank, or other components on a reciprocating machine.
Coupled with the NXA Pro, it’s a run out probe. A dial indicator. A micrometer. A documenter. And a great diagnostic troubleshooting tool!