Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #1 – Learn Some New Moves

Of course, the #1 reason is that, with a strobe light, you can learn to do this (ok, maybe…😉)

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #2 – Phase Analysis

One of the most powerful diagnostic tools we have is phase analysis and using a strobe light is a versatile and powerful tool towards that end. As with Frequency Confirmation, you will need a phase-capable strobe for phase, one capable of communicating with your analyzer (and an analyzer that supports that function, of course).

Phase with a strobe light is a exercise in recording (or remembering – we recommend recording) visible data. You are looking at the angular location of the key, or another mark, as you move the sensor from location to location, often recording the results on a bubble diagram on some rudimentary drawing you’ve made of the machine and base. Obviously, this will not be nearly as accurate as a tach or photo-eye but unless you are balancing, using clock face numbers is sufficient for a general phase analysis. Surveying the diagram often reveals an anomaly that, in turn, leads you to the fault and the solution.

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #1 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #3 – Frequency Confirmation

For the next two reasons, you’ll need the super duper extra special strobe light that communicates with your data collector and does phase. Requiring a sensor, the analyzer actually triggers the strobe light using the vibration signal, thereby freezing whichever component is the source. This is particularly effective on belt drives, where three separate rotational speeds exist.

Understanding spectrum analysis means understanding that the frequencies displayed are calculated with a margin of error. By using the measured signal to trigger the strobe to flash, it will flash at a rate that 100% freezes the component generating that signal, removing ALL doubt as to the source. So why would anyone rely on an assumption when you can remove all doubt by executing a simple test? I don’t know but I do know that I once found, only because of this test, a fault at a frequency that was 1 cpm different than 1x. It was, in fact, the only thing that stopped what would have been a $30,000 mistake.

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #2 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #4 – Belt Inspections

Belt inspections are singled out from other types of inspections due to the difficulty of using a strobe light on a lower frequency and belts often run at <500 rpm. Rather than a simple key or mark, you are trying to find some recognizable lettering on the back of the belts at a relatively slow flash rate – it can be virtually impossible.

An easier technique is to flash at least 1000 cpm or higher and lock in on a multiple of belt rpm rather than 1x. Once you have a lettering pattern frozen, you can tune away slightly and perform the same slow motion inspection on the belts, accurately assessing belt condition even while flashing at 2x or 3x belt speed.

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #3 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #5 – Belt Drives: Bent Shafts and Pulley Wobble/Runout

Although a dial indicator would be the preferred method for accurately determining the degree of faults like these, a strobe can often help when the machine cannot readily be shut down. We start with the same basic Slow Motion Study approach (are you sensing a pattern…?)

Starting with the driven shaft, by lining up the edge of the pulley or shaft with a fixed point on some structure behind it, you can watch for any movement of the shaft that shouldn’t be there in both the radial direction (runout, eccentricity, bent shaft, etc.) and the axial direction (cocked pulley, bent shaft, etc.).

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #4 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #6 – Structural Looseness

Ever see amplitudes increase drastically at 1x? Did you know that a strobe light is a great way to inspect for structural looseness, often the cause of such a sudden increase (literally – something broke)? To do this, we utilize the very same Slow Motion Study techniques we discussed previously.

By tuning to the frequency of interest and then tuning slightly away from that, you will be amazed at some of the things you can see happening on the structure. Sometimes you need to play a bit with your flash rate but you will find this to be a useful technique in finding broken welds, loose feet, housing distortion, loose and broken fasteners and many more causes of abnormally high amplitudes.

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #5 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.

Top 10 Reasons Why a Strobe Light is an Analyst’s Best Friend: #7 – Verifying 1x

One mistake I’ve seen made over and over is an analyst fails to verify that what they believe to be 1x is actually 1x. This happens for one simple reason: more than one single flash rate will cause a single mark to appear. What about 1/2x, when the flash rate is once every two rotations? Or 1/3x?

The simple test is to double your flash rate from what you believe to be 1x. If two marks appear, meaning you are now flashing twice per rotation, you are correct. If not, you have more work to do.

This tip is provided by Scott Dow, Senior Instructor of Mobius Institute.

Come back to our blog next week to read #6 in our Top 10 Reasons Why a Strobe Light is an Analyst's Best Friend. To learn more about IMVAC and the event nearest to you, visit vibrationconference.com.