Coupling Tolerances vs. Shaft Alignment Tolerances, revisited

We have several blogs discussing the differences between coupling alignment tolerances and precision shaft alignment tolerances (see links below). As stated in those blogs the coupling manufacture’s tolerances are for the coupling. As maintenance professionals we are concerned with the coupling, however we are more concerned with the bearings in the machines. Precision shaft alignment…

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Know Your Alignment Tolerance

VibrAlign and Fixturlaser have done what we can to make the precision shaft alignment process quicker and easier for the end user of our tools. To assist maintenance personnel during an alignment a tolerance table “pops up” on the display unit screen (of our tools) when entering dimensions for the machines being aligned. The tolerances…

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Setting Tolerances in Fixturlaser Shaft Alignment Tools

Fixturlaser Shaft Alignment Tools come pre-programmed with generally accepted industry tolerances for electric motor driven machinery.  These tolerances are based on the motor RPM and will give you an “endpoint” in the alignment process (based on the measured offset and angular misalignment at the center point of the coupling in both the vertical and horizontal…

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Alignment Considerations of Machines with Stiff Elastomeric Couplings

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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Back Off Jack Bolts for Improved Alignment Results

Millwrights and mechanics know the benefits of using jack bolts to precisely control the horizontal position of the movable machine when performing a precision shaft alignment. However, we also see the tendency to tighten the jack bolts, on both sides of the movable machine, either before or after tightening the hold down bolts. Tightening jack…

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Fudging Your Shims? Go The Same Direction.

When performing a precision laser shaft alignment, it is best to add or remove shims exactly as the display unit indicates.  There are circumstances when this may not be possible due to your assortment of shims, or when you want to “fudge” your shims slightly to keep the total number of shims low. (Clink for…

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Reduce Force to Maximize L10 Bearing Life

Simply put, L10 bearing life is the number of service hours that 90% of bearings will survive or conversely 10% of bearings will have failed. L10 life: is the preferred term in specifying bearing life and is defined by The American Bearing Manufacturers Association (ABMA). A bearing life equation is: This calculation assumes proper installation…

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Coupling Tolerances vs. Shaft Alignment Tolerances, What’s The Difference?

Plenty! This question still comes up fairly often in our training classes. If you look any of the coupling manufactures installation instructions there is a chart for the maximum allowable misalignment based on the coupling size. These tolerances are for the coupling, what about the machines the coupling connects? Shaft alignment tolerances are more about…

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