Since the numbers were close, although not exact, he was hesitant about what was going on. The customer insisted on trying to balance it again but we had the same exact problem. This time our engineer was sure he made all the correct moves and that something was not acting linear like a normal balance issue. So we recommended bringing the unit to our dynamic rotor balancing center so we could verify the balance condition. The customer was already two days late in starting up the plant and did not want any additional delays but saw no other options as the vibration was too high to continue to operate the machine.

We quickly saw the issue with the fan after a couple of runs on the balancing machine. The readings were always changing and we could hear material inside the fan. Our curiosity quickly had us to drill a hole in the area of the noise and suddenly all kinds of fine dirt and rust started to flow out from the opening. When it was done, we measured six pounds of material was taken from the center of the fan.

Now with all that weight removed, the fan balancing made sense once again. We made a precision balance on the unit to 2W/N and put it back into service. Before the unit started up some personnel took cover but it came up below 0.1 ips and running smoother than ever.

Our engineer learned to trust his instincts. When a rotor does not look like it is repeating, take another run or so to verify it and if the rotor does not show normal linear results then there is soemthing else going on.

So many repairs are band-aids that unfortunately will be revisited in the not too distant future creating the never ending spiral.  These Herculian efforts go unappreciated as eventually the problems overwhelm the department and more heads roll.  Most often the best personnel are let go or the department is outsourced so all the competency and knowledge is lost.    

As many companies learn, in these circumstances during the lean times, predictive maintenance, condition monitoring and NDT technologies can turn this whole situation around.  Instead of running from failure to failure, these technologies identify problems sooner so they are much smaller and much less costly to resolve.  They can identify the specific faults in the equipment so you do not just apply a band-aid to only part of the problem but you fix all the issues.  However if you are not committed to making all the necessary repairs identified by the technologies, then nothing really changes except that now you know that the crack in the bearing cage will probably give out in the next 3-6 months. 

If your management does not believe in you, having this knowledge is an extremely powerful way to turn them to your side.  If they are unwilling to provide you the funds and time to make the total repair, you can become a prophet by explaining the problem and how it will ultimately fail creating additional work in a few months.  Some managers will ignore your wisdom but as your predictions come true you will quickly gain their attention and trust.   

Just remember that knowledge is power and the predictive technologies give you all the knowledge you could ever want.  It is never nice to watch the train wreck as it approaches but sometimes that is the way management wants it until they get the bill.   Now capture the momentum to articulate your argument that the predictive technologies see the future and help you avoid the train wrecks.

A vibration spectrum can show you that you have a bearing problem or a misaligned coupling but wouldn’t you like to verify your analysis with a different technology to confirm those findings. How difficult is it to take an infared scan to see what the coupling looks like and if it confirms your diagnosis.  Or how about pulling out your ultrasound to make sure the bearing sounds rough. 

You will find taking the time to confirm your results will ensure you make the right call.  More importantly you will most likely find additional faults that the initial technology did not even identify.  As a result, you will resolve more equipment problems meanwhile raising the reliability of your plant.

One critical refinement came when Nicholas Akimoff, Vibration Specialty’s founder, developed a balancing machine.  Instantly he became a part of high society in the United States as his new machine allowed Henry Ford to balance his crank shafts and Thomas Edison to balance his motors, generators and turbines.  Suddenly machinery vibration was no longer tolerable and every product required balancing if it were to be accepted by industry.  In fact, during World War II all VSC employees were exempt from the draft because our balancing machines and services were vital to the defense of the country as we balanced all the Navy’s propellers. 

Knowing this history of the evolution of machinery vibration and balancing makes it easy for us to see how the world seems to be forgetting many of the lessons our forefathers spent learning and refining.  Every day we see new and repaired parts such as sheaves, couplings, pumps and fans that are not even balanced or have extremely loose balance tolerances to make them seem as if they were not balanced at all. 

Unlike today, in three quarters of the last century, machinery was built on stout bases with ample concrete and solid I beams.  These extremely solid foundations provided a huge margin of error that even if a machine was improperly balanced it still ran decently. Now everything revolves around the mighty dollar.  Every part must be manufactured with the least amount of material so we can remain competitive by keeping the price down.  As a result, machinery is made of rinky dink sheet metal with L brackets as the foundation.  Then in order to save energy we run this machine on a Variable Frequency Drive motor and wonder why the machine either lasts only a year or is shaking itself to death. 

There is nothing wrong with making machinery with less materials but we must remember nothing is for free.   If you want to save money using less material then you must spend more time designing the system to tolerate all the forces it will encounter.  As we use less and less materials our tolerance for error becomes extremely fine.  We need to become more precise with our balance tolerances, clearances, materials and parts if we expect the machinery to operate well and last for years.  

From where we sit right now, there is no end to this less is more mentality. As a result, this makes VSC’s technologies and services in vibration analysis, infrared thermography, ultrasound, dynamic balancing, and laser alignment even more critical to making your machinery operate well with a long life expectancy.      

One thing we know is if we do not learn from history, we are doomed to repeat it and at this moment it looks like we are heading toward inferior maintenance practice that at some point will bite us.  Predictive and Precision Maintenance are the only solutions that will allow todays equipment to operate as smoothly and as long as it did in years past.