Posts by: Stan Riddle

Pump Vibration – Even Cavitation Isn’t Always Cavitation!

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By on August 2, 2017

Most people who work on, or around pumps are familiar with the term “cavitation”.  It is often used as a catch all phrase for any flow-related vibration on pumps, and is often reported by vibration analysts when: Pump noise level is high, Pump vibration is erratic, with lots of “noise” in the spectrum. But there […]

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Critical Machines? It Depends on Who You Ask

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By on July 20, 2017

I recently taught alignment training at a gas compression site.  These were sharp technicians, and they keep these large gas compressors in excellent shape.  We went out to check alignment between the engine and compressor.  It was great just as I expected, because compressing gas is their only product. So I asked if they had […]

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The Cure for Alignment Frustration!

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By on June 28, 2017

A customer called me, extremely frustrated, because he could not get a good alignment.  “I’ve spent two hours trying to align this stupid pump!” he said.  He blamed the laser, the “cheap” pump his company had, the bad base, his bad trainer (me), and anything else that came to mind. I did not take it […]

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TROUBLESHOOTING MOTOR UNBALANCE

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By on June 20, 2017

Electric motors are almost always well-balanced when they leave the motor manufacturer.  But occasionally, motor unbalance problems are picked up with vibration monitoring tools, such as the OneProd Hawk. Here are some easy troubleshooting methods to determine the cause of unbalance in the motor. An electric motor’s rotor, like any rotating mass, cannot become out […]

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Roughing In Before Precision Shaft Alignment

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By on June 1, 2017

Some people believe that precision laser shaft alignment has evolved to the point where pre-alignment steps, such as roughing in the alignment with a straightedge, are no longer needed.  Well, quite frankly, those people are wrong! The reason for roughing in the alignment has little to do with how accurately the lasers/sensors measure.  It has […]

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Setting Up a Motor-Gearbox for Vibration Measurement

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By on May 25, 2017

Gearboxes are common in industry.  They are used to increase or decrease speed from the driver, provide increased torque, and change direction of power transmission.   There are two main types of commonly-used gearboxes:   GEARBOX TYPE Parallel or Standard Gearbox-one where the input and output shafts are parallel. Bevel or Right Angle Gearbox-one where […]

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Precision Shaft Alignment of Machines With Small Diameter Shafts

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By on April 27, 2017

A VibrAlign customer recently called, stating they were having repeatability problems with aligning a small motor to gearbox to pump.  After some phone conversation, I asked if they could send me photos of the machine, and the discrepancy in the measurements.  After seeing them, I knew what the problem was.   Machines with small diameter […]

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When Should You Replace the Coupling Insert?

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By on March 30, 2017

In industry, many couplings utilize an elastomeric insert or element.  This type of coupling has many advantages, among them: Ease of replacement Ability to absorb torsional loading No need for lubrication Tolerant of slight amounts of misalignment Inexpensive It is important to remember that even though these elastomer couplings can be tolerant of misalignment, the […]

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Hammer Time-and When it’s NOT!

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By on March 8, 2017

    At VibrAlign, we are in the precision maintenance business.  Our tools, our training, and our people, are all about precision maintenance.  While teaching the field alignment portion of our shaft alignment training, at a customer site, we went out to align a particularly troublesome pump.  They didn’t think they were getting the life […]

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The One Tool Missing in Most Aligner’s Toolboxes

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By on January 18, 2017

I am going to pass along to you a gift – one that I believe could potentially cut your alignment times-maybe by more than half!  One that could lessen loosening and tightening bolts, reduce frustration, and increase your “alignment” confidence substantially!  Would you like such a gift? Well, here it is – measure your shim […]

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Alignment Considerations of Machines with Stiff Elastomeric Couplings

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By on December 28, 2016

These types of couplings are quite common in industry, and there are various companies producing similar types of couplings.  They are capable of transmitting large amounts of torque in a reasonably small space.  They also do not require lubrication, and are quite easy to install, in most circumstances.  These attributes make them quite desirable in […]

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Base Bound Machinery Corrections

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By on December 2, 2016

Most aligners are familiar with a bolt bound situation, which occurs when the motor cannot be moved enough to achieve proper horizontal alignment.  A base bound condition occurs when a motor cannot be lowered sufficiently to achieve proper vertical alignment.  Here is an example.  During a customer’s recent pump replacement, the motor was left in […]

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MACHINERY VIBRATION PROBLEMS AND SOLUTIONS, PART 6 – RESONANCE

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By on September 15, 2016

Resonance is when a force causes an object to “resonate”, due to excitation of its natural frequency.  Think of a machine coasting down to a stop.  There are certain speeds in coasting down that excite natural frequencies of the machine components.  This is often observed in the coast down of a bench grinder.  As the […]

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Shim Safety

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By on September 1, 2016

We recently received a customer request about shim safety.  An employee at the customer site had experienced a “near miss” safety issue due to walking too closely to a machine, and getting their clothes caught against a shim.  Since I have a scar on my right thumb caused by a 3 mil shim, I thought […]

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MACHINERY VIBRATION PROBLEMS AND SOLUTIONS, PART 5, MECHANICAL LOOSENESS

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By on August 3, 2016

Mechanical looseness is a very common machine vibration diagnosis.  It is often overused-becoming a “catch all” category for undiagnosed vibration.  It can be caused by a multitude of things that may seem to have no relationship to each other, such as:   Loose bolting                                               Coupling looseness or backlash Belts Too Loose                                           Cracked welds Improper bearing […]

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