# Do you align shafts?



## BBQ (Nov 16, 2010)

MDShunk said:


> Do you align shafts


Is that like docking?

If so no.


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## drsparky (Nov 13, 2008)

No way, the millwrongs have the equipment, parts and training. I am glad they do it when you see them shimming big motors, looks like a pain in the butt.


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## HARRY304E (Sep 15, 2010)

BBQ said:


> Is that like docking?
> 
> If so no.


This is what he is talking about...
http://www.maintenanceresources.com/referencelibrary/ezine/fiveerrors.html



http://www.pump-zone.com/articles/39.pdf


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## BBQ (Nov 16, 2010)

HARRY304E said:


> This is what he is talking about...
> http://www.maintenanceresources.com/referencelibrary/ezine/fiveerrors.html
> 
> 
> ...


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## HARRY304E (Sep 15, 2010)

BBQ said:


>


 Thanks for the encouragement..:thumbup::laughing::laughing:


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## Mike in Canada (Jun 27, 2010)

Millwrongs? Very nice, Mr. Sparky.

I am also a journeyman millwright, so yes I align motors. That having been said, it doesn't happen that often. A week or two ago I was changing motors on four pumps, and I aligned all four, but it was a very minimal alignment, and it was the first time in a year that I'd aligned any. In this day and age where virtually all inline motor set-ups are either close-coupled (where the pump bolts directly to the face of the motor, and needs no alignment) or at least they use an elastomeric coupling like a lovejoy or similar, the alignment is not nearly as big a deal as it once was. With a solid coupling you needed to be well within a thou or you would be vastly shortening the life of the bearings in both the pump and motor. I've personally seen extreme cases where the input shaft of the pump cracked right off because the alignment was off by about half a degree.
In a case like that you'd clock out the couplings and the feet, and it might take an hour or two to do a proper job of a 20 horse motor. Nowadays, unless it's a 100+ HP motor all I use is a 6" scale to align the coupling faces. The couplings will take a reasonable amount of misalignment before there is trouble.
There are still times when a motor needs to be aligned properly, and the specialists use lasers and whatnot to align motors much more quickly than we could with dial indicators. Still, with a 6" pocket scale and 10 minutes I can get a motor close enough for normal use with an elastomeric coupling.
Of course, you need to run it and do the 'laying of hands' to verify that everything is good. Guys who do a lot of alignment would have vibration meters, etc.


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## drsparky (Nov 13, 2008)

Mike in Canada said:


> Millwrongs? Very nice, *Mr. Sparky.*
> 
> I am also a journeyman millwright, so yes I align motors. That having been said, it doesn't happen that often. A week or two ago I was changing motors on four pumps, and I aligned all four, but it was a very minimal alignment, and it was the first time in a year that I'd aligned any. In this day and age where virtually all inline motor set-ups are either close-coupled (where the pump bolts directly to the face of the motor, and needs no alignment) or at least they use an elastomeric coupling like a lovejoy or similar, the alignment is not nearly as big a deal as it once was. With a solid coupling you needed to be well within a thou or you would be vastly shortening the life of the bearings in both the pump and motor. I've personally seen extreme cases where the input shaft of the pump cracked right off because the alignment was off by about half a degree.
> In a case like that you'd clock out the couplings and the feet, and it might take an hour or two to do a proper job of a 20 horse motor. Nowadays, unless it's a 100+ HP motor all I use is a 6" scale to align the coupling faces. The couplings will take a reasonable amount of misalignment before there is trouble.
> ...


 It's Dr. Sparky, I didn't spend six years in Evil Medical School to be called "mister," thank you very much.


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## Big John (May 23, 2010)

Mike in Canada said:


> ...In this day and age where virtually all inline motor set-ups are either close-coupled...or at least they use an elastomeric coupling like a lovejoy or similar, the alignment is not nearly as big a deal as it once was....


 Thank goodness for that. Almost all the motors I replace have some sort of flexible coupling, belt, or chain that will tolerate quite a few thousands of alingment-ineptitude on my part.

-John


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## miller_elex (Jan 25, 2008)

I used to do it on a fairly regular basis with shim kits and a dial mike.

Even if you pull the motor to replace bearings, I'd keep track of where everything was and mike it.

Here the pipefitters do all that stuff.


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## electricmanscott (Feb 11, 2010)

We bring somebody in with laser alignment equipment. It's so futuristic. :laughing:

Leave it to the "pros".


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## John Valdes (May 17, 2007)

When I worked in industrial, it was the electricians job to align the motor as well as hook it up.
If it was super important, we would have someone laser align it. But in most every instance we did it ourselves.


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## dowmace (Jan 16, 2008)

I have always aligned and shimmed motors myself. But I have proper training and tools and all that BS that goes with things of that nature. I don't suggest that everyone do it their self there are plenty of electricians I barely trust to make up a recep.


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## erics37 (May 7, 2009)

No, I don't "align shafts."

I don't do it at work either.


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## Jlarson (Jun 28, 2009)

I do, dial indicators or lasers. Although lately with almost everything I work on now I can do the same thing Mike in Canada does and just use a little metal rule.


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## micromind (Aug 11, 2007)

It depends on the type of coupling, speed, and HP of the motor. 

If it's a basic Lovejoy that's under 100HP, then all I use is a steel rule and feeler gauges. 

Other types or higher HP, I'll use a dial indicator. Especially if it's 3600 RPM.

Some I won't do at all.


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## oldtimer (Jun 10, 2010)

John Valdes said:


> When I worked in industrial, it was the electricians job to align the motor as well as hook it up.
> If it was super important, we would have someone laser align it. But in most every instance we did it ourselves.


 When I worked at an iron ore mine, we did the alignment (motor to pump example), but we usually worked with a millwright.

It worked out great.


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## miller_elex (Jan 25, 2008)

micromind said:


> If it's a basic Lovejoy that's under 100HP, then all I use is a steel rule and feeler gauges.
> 
> Other types or higher HP, I'll use a dial indicator. Especially if it's 3600 RPM.


Yeah, I haven't done anything above 40hp, and all pumps and fans. I'll let the big boys do that 300hp circ pump.


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## TOOL_5150 (Aug 27, 2007)

BBQ said:


> Is that like docking?
> 
> If so no.




You browse the internet too much... :laughing:

~Matt


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## MDShunk (Jan 7, 2007)

Mike in Canada said:


> Millwrongs? Very nice, Mr. Sparky.
> 
> I am also a journeyman millwright, so yes I align motors. That having been said, it doesn't happen that often. A week or two ago I was changing motors on four pumps, and I aligned all four, but it was a very minimal alignment, and it was the first time in a year that I'd aligned any. In this day and age where virtually all inline motor set-ups are either close-coupled (where the pump bolts directly to the face of the motor, and needs no alignment) or at least they use an elastomeric coupling like a lovejoy or similar, the alignment is not nearly as big a deal as it once was. With a solid coupling you needed to be well within a thou or you would be vastly shortening the life of the bearings in both the pump and motor. I've personally seen extreme cases where the input shaft of the pump cracked right off because the alignment was off by about half a degree.
> In a case like that you'd clock out the couplings and the feet, and it might take an hour or two to do a proper job of a 20 horse motor. Nowadays, unless it's a 100+ HP motor all I use is a 6" scale to align the coupling faces. The couplings will take a reasonable amount of misalignment before there is trouble.
> ...


I was mainly wondering, because I tore up a $5,800 gearbox. It was within spec of the coupling (woods elastomeric), but not within the gearbox mfgr's spec. The coupling guy was called in by me. He said that their spec is only how much misalignment the coupling can tolerate, and that the driven unit manufacturer's spec still needs to be followed. That being so, the .012" misalignment I had was within spec for the coupling, but not the .002" the gearbox mfgr wanted.


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## pudge565 (Dec 8, 2007)

I will probably learn how to do it at work being general maintenance right now. That is if a motor takes a crap that is coupled. When we change clutches or the transmission coupling (not the motor to drive) we place the shims in a way that we can put them right back in where they came from.


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## Big John (May 23, 2010)

MDShunk said:


> ...That being so, the .012" misalignment I had was within spec for the coupling, but not the .002" the gearbox mfgr wanted....


 Hard way to learn a lesson, but thanks for sharing it. Honestly, I would've expected the coupling to take up the slop so it wouldn't have even occurred to me that the gearbox would have seen the misalignment. 

I've installed many a flexible coupling based on that theory. I'm gonna be more careful now.

-John


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## McClary’s Electrical (Feb 21, 2009)

MDShunk said:


> Electricians's work often involves changing failed motors. Very often, these motors are inline coupled by some means to driven equipment. This is properly a millwright's job to align and shim the motor. Some electricians do it. Do you align shafts yourself, sub it out, or tell them to get someone?


 

It depends on what it is. If it's 100 HP on an air compressor with a lovejoy coupling that is allowed by the manufacturer to run +or - .015 then I'll use my dial indicators and feeler guages and line it up myself. If you'd like I'll post some pics of my alignment tools. 

But in the case of the 4160 generator that I posed pics of, I had Nicky Allen with Electrical Equipment come in and laser line it for us. The machine he has is really slick. You type in the dimensions on the footprint. You then align laser facing each other on each shaft. Then make one full rotation. The computer then tells you exactly how much shim to put under each place, and tells you which way the motor needs to move to be inline. No guess work.


The biggest motor I have ever personally done myself was 400 HP and I've done several of those. Dial indicator and feeler guages is all you need.


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## miller_elex (Jan 25, 2008)

mcclary's electrical said:


> The biggest motor I have ever personally done myself was 400 HP and I've done several of those. Dial indicator and feeler guages is all you need.


I don't know how you came to be such a pimpster.


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## MDShunk (Jan 7, 2007)

pudge565 said:


> I will probably learn how to do it at work being general maintenance right now. That is if a motor takes a crap that is coupled. When we change clutches or the transmission coupling (not the motor to drive) we place the shims in a way that we can put them right back in where they came from.


That will get your height right in elevation view, but does nothing for angular misalignment in plan view (view from above). Both are equally important. Just putting the shims back under the same feet is only 1/2 the job (assuming same motor). If it's the same motor, the last guy might have doweled it, so that will set your angle for you. If no dowels, you still got to break out the dial indicators or whatever you use. I'll admit I'm surprised that so many guys only use a 6" steel rule.


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## pudge565 (Dec 8, 2007)

MDShunk said:


> That will get your height right in elevation view, but does nothing for angular misalignment in plan view (view from above). Both are equally important. Just putting the shims back under the same feet is only 1/2 the job (assuming same motor). If it's the same motor, the last guy might have doweled it, so that will set your angle for you. If no dowels, you still got to break out the dial indicators or whatever you use. I'll admit I'm surprised that so many guys only use a 6" steel rule.


Hmm interesting. I don't know what you mean by doweled it. Our couplings wont allow for an angular misalignment I don't think due to the design although I may be totally wrong.

After some research they allow for a bigger misalignment margin. This is what we have installed. http://pt.rexnord.com/products/couplings/steelflex_grid_couplings/steelflex.asp


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## Mike in Canada (Jun 27, 2010)

MDShunk said:


> I was mainly wondering, because I tore up a $5,800 gearbox. It was within spec of the coupling (woods elastomeric), but not within the gearbox mfgr's spec. The coupling guy was called in by me. He said that their spec is only how much misalignment the coupling can tolerate, and that the driven unit manufacturer's spec still needs to be followed. That being so, the .012" misalignment I had was within spec for the coupling, but not the .002" the gearbox mfgr wanted.


 That's ugly. If you were only twelve thou off then you should have been fine. It could be that the gearbox was a dud and they're hiding behind the alignment to avoid a pay-out. Still, you make a good point... if the warranty requires strict alignment then you have a choice to make. I could have easily made the same error.


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