Machinery Maintenance

Are Shims Causing a Soft Foot Issue?

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By on May 15, 2018

One of the many things I love about my job is the numerous challenges we face during the field alignment portion of our Precision Shaft Alignment Training. Prior to the training, there were some repeatability issues when attempting to perform a precision alignment on this piece of equipment. One of the main causes of non-repeatability […]

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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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Installation Errors Part 2 – Shims and Shim Handling

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By on May 3, 2018

The difference between luck and success is this; Luck is when you achieve a desired result despite mistakes made along the way. Success is when you follow a known process to achieve the expected result. When attempting a precision shaft alignment, precise practices must be followed. One thing for certain in precision alignment is the […]

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Understanding Spacer Shaft Alignment

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By on April 25, 2018

The majority of precision shaft alignments are relatively close coupled where there are only a couple of inches between the shaft ends of the driver and driven elements. Close coupled alignment quality is traditionally displayed as angle (driver to driven) and offset (at the center of the coupling). The question is what do you do […]

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Dial Indicator Alignment – Bar Sag Still Exists in 2018!

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By on April 17, 2018

And it just may be a lot more than you would think. While visiting a customer site to do an alignment check using the EVO laser alignment tool on a 1750 HP Electric Motor / Boiler Feed Water Pump / 3574 rpm, measurements were taken several times (x3) to make sure the values were repeatable.  […]

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Channel Strut as a Motor Sub-base?

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By on April 12, 2018

At first thought it may sound like a good idea as the specialized fasteners in the channel make it easy to tighten the motor hold down bolts, however in reality it’s a cause for precision shaft alignment issues. Here’s why. A good pump/motor base is engineered to meet specific standards (IE: ANSI, API, etc.) with […]

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Challenging, But Not Impossible!

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By on April 3, 2018

As we trainers travel around the country conducting precision shaft alignment training, we often run into some fairly harsh work environments during the field portion of the training. At times the equipment that needs to be aligned is caked in product from spills or leaks. This can create a significant challenge when attempting a precision […]

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Installation Errors Part 1- Coupling Care and Balance

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By on March 28, 2018

Observing a training class of new mechanics can sometimes be a stressful proposition for a former field Millwright. Especially when said millwright has control issues.  As part of our Precision Shaft Alignment Training, the trainees move from the classroom setting into the field to practice what they have learned. Transferring the knowledge gained in a […]

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Should Soft Foot Be Corrected in Centrifugal Pumps?

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By on March 20, 2018

  In a previous blog I wrote in Jan of 2016 “Soft Foot Concerns in the Stationary Machine?” soft foot in the pump was causing repeatability issues during a precision shaft alignment. https://vibralign.com/other-topics/soft-foot-concerns-stationary-machine/ Soft foot can also distort the pump casing which can change clearances within the casing. This can shorten the life of the […]

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Calculating VFD Motor Speed

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By on March 13, 2018

When using the Fixturlaser Smart Machine Checker (SMC) or any of VibrAlign’s Condition Monitoring Tools, there are typically only two variables you need to know for an accurate diagnosis of your machine.  You need the horsepower of the motor and the correct rotating speed.  This information will usually be stamped on the motor data plate.  […]

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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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Soft Foot! Or Are You Just Pulling My Leg?

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By on February 12, 2018

It’s no joke that many machines operate with high levels of vibration due to soft foot.  These same machines often have a decreased life span due to this condition. Soft foot is a condition that should be eliminated during the precision shaft alignment process, if you’re performing proper alignments at all.  This condition can manifest […]

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Stupid Questions

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By on February 8, 2018

While on the road conducting precision shaft alignment training I run across a wide range of skill level. It is not uncommon to have a lot of questions. I like it when there are questions, that is usually an indication that the trainees are engaged. It is also not uncommon that a question starts with, […]

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