Shaft alignment methods

[Tech Rob]

I could say something really snide like, "I don't think we could cover it all in two days", but I won't (Hey - you opened the door)

You're probably right.

[double bogey]

The outfit I used to work for needed documentation on a couple of jobs so we bought a laser alignment setup. You could learn to use it in about half an hour. I brought a class in on a Saturday and trained them how to use dials (we had a pump on a base). Once they got a handle on that we broke out the laser. All picked it right up. After that our young guys who went to the class could run rings around the guys who didn't want to learn the laser. It also provided printable documentation of the alignment.

[valdelocc]

The outfit I used to work for needed documentation on a couple of jobs so we bought a laser alignment setup. You could learn to use it in about half an hour. I brought a class in on a Saturday and trained them how to use dials (we had a pump on a base). Once they got a handle on that we broke out the laser. All picked it right up. After that our young guys who went to the class could run rings around the guys who didn't want to learn the laser. It also provided printable documentation of the alignment.

all the laser systems are based on reverse dial alignment, I've never use the laser but I see guys using it and its pretty simple, straight forward system, the computer tells you what size shim and where to put it, the only reason I still use indicators is money, the laser cost 10 times or more the price of the dial indicator setup, I also think that by dummy down our trade we are shooting ourselves on the foot.

[Tommy knocker]

You really can't go wrong with the thumb up, left eye closed method.

[passintyme]

I use a good ol stick rule on belt drive units.. I teach the newbies the 4 point rule on straight edges and use dial for the big boys... Everyone is correct when they say it is a dying art. I only do about twice a decade, which makes for a poor showing on my part.

[double bogey]

Just for grins, take a shaft and fix your indicator to it. Zero the indicator and then turn the shaft over and see what it reads.

[DeltaT]

Pictures and/or videos would be nice.

[Tech Rob]

Just for grins, take a shaft and fix your indicator to it. Zero the indicator and then turn the shaft over and see what it reads.

If you zero it at the top, I think it'll read sightly negative on the bottom of the shaft due to sag.

[double bogey]

If you zero it at the top, I think it'll read sightly negative on the bottom of the shaft due to sag.

This, it really suprised me when a coworker showed this to me. Shook my confidence with the dials.

[coolerik]

You really can't go wrong with the thumb up, left eye closed method.

Yup

[valdelocc]

This, it really suprised me when a coworker showed this to me. Shook my confidence with the dials.

well my friend, the laser is also prone to sag and one of the first steps for indicator or laser alignment is to compensate for sag, around -2 mils, I blame gravity for it.

[klove]

This, it really suprised me when a coworker showed this to me. Shook my confidence with the dials.

Why would it be an issue? Sag is nothing but a natural force that's going to be repeatable if the setup is the same. Simply set your indicator up on a piece of pipe or shaft over the same span as your work will be done, zero, roll 180°, read the sag, compensate at 12 o'clock before starting your vertical parallel reading and read 6 o'clock directly. Longer the span, worse the sag. If you test the runouts on all parts and they're within tolerance, then the only part of the process that sag is an issue for is the vertical parallel. Sag is the reason that I use face and rim instead of reverse indicator. Easier for me to deal with in that manner.

[Keep'N It Cool]

Dial indicators work, but when a customer requires documentation laser alignment is the way to go. The company I work for has a laser alignment tool for shaft alignment. Most of our trucks have Pulley Partners for Pulley and belt alignment. The laser shaft alignment tools are not cheap, I think around 5k for a cheap one and like 15k for the high end if not more. With a laser alignment you have a calibrated instrument to tell you you have it right. When we higher a vibe and alignment company they use a laser alignment, but also have dial indicators to check run out.