Posts by: Stan Riddle

You Can’t Perform Precision Alignment on Un-precise “Stuff”!

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By on May 11, 2018

Alan Garbers with Johnson Controls International contacted me regarding an alignment problem, and asked for my advice.  Here is a condensed version of his email. A client rents portable chillers, and related equipment. They built a 125HP portable pump skid with a Bell & Gossett pump on a VFD. I was there to commission the […]

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The Soft Foot Primer (Part 3) How to REALLY Minimize Soft Foot Every Time

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By on March 4, 2018

It is both possible, and desirable, to minimize the negative effects of soft foot.  While it may be difficult to completely get rid of soft foot, it can typically be reduced to a few mils, if the following techniques are used. PREPARATION AND CLEANLINESS CLEAN! If you remove the motor, wipe the feet clean, before […]

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The Soft Foot Primer (Part 2) Vibration and Alignment Problems Related to Soft Foot

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By on February 26, 2018

Most industrial maintenance mechanics who are involved with precision shaft alignment are familiar with the phenomenon of soft foot.  From an alignment standpoint, soft foot causes: Changes in alignment values, between when the hold down bolts are loose, and when they are tight. Non-repeatability in alignment measurements, especially if the bolts are not tightened in […]

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The Soft Foot Primer (Part 1) Are You Measuring Soft Foot, or Just Its Effect?

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By on February 19, 2018

Most laser alignment tools include a soft foot function. However, in truth these tools haven’t measured ACTUAL soft foot, instead they have measured the EFFECT of soft foot at the shaft or coupling as that is where the laser heads or sensors are mounted.  While the EFFECT of soft foot is important, correcting the ACTUAL […]

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The Role of Fasteners in the Alignment Process

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By on January 24, 2018

Fasteners are a critical component of the precision shaft alignment process, yet the importance of fasteners is many times overlooked.  If bolting is not selected, assembled, and torqued correctly, it can make the precision shaft alignment process less accurate, more difficult to achieve, and potentially harmful to the machines. While there are always unusual circumstances, […]

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Why You Should Perform Shaft Alignment as Part of Your PM

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By on December 27, 2017

James Pekarek, one of our trainers, wrote a blog entitled “Performing Alignment Checks as Part of Your Preventive Maintenance”. https://vibralign.com/shaft-alignment/performing-alignment-checks-part-preventive-maintenance/ It is a great article, and good advice.  I recently shared this blog post, and the advice, with a customer of ours.  Here’s why. I taught a training class at a large water plant in […]

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Is It Mils, or Thousandths, or What?

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By on December 1, 2017

On occasion, we are asked, “What are these numbers on the screen?”  All our alignment tools (and most others) can be configured in Imperial or Metric.  Most US users use Imperial (inches, feet, and so on). When we say, “Your laser displays in mils”, we’re asked, “What’s a mil?” Definition – [mil] noun. 1. a […]

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What is the Fixturlaser NXA Runout Probe?

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By on November 7, 2017

VibrAlign has introduced the Fixturlaser Runout Probe, an accessory device for the Fixturlaser NXA Professional.  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!  […]

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Fix the Easy Things First!

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By on October 26, 2017

One of the hallmarks of a good maintenance technician is the ability to troubleshoot – not just using vibration tools, or volt meters, or laptops with Ethernet plug-ins, but the ability to troubleshoot machinery in their minds.  In other words, the ability to visualize what the problem might be. “Fix the easy things first” is […]

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Vibration Sensor Mounting Tips

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By on September 13, 2017

A vibration sensor (or accelerometer) measures vibration-simple, right?  But how and where you mount the sensor is CRITICAL to getting good information.  Here are some good tips to keep in mind. 1. Mount the sensor as close to the bearing location as you can safely do it. These sensors can measure vibration anywhere on the […]

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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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