Categories: Shaft Alignment

Stacking the Deck Can Get You in Trouble!

By on November 13, 2011

The photo to the right was taken at a recent training class. The maintenance guys at this facility were excellent aligners. They were adamant about getting their shaft alignments to “better than excellent” levels. They believed in preparing the surfaces of the base and the motor before installation. Their company spent thousands of dollars re-working piping and bases to minimize the chance of pipe strain or bolt bound conditions.

They were careful to measure, correct, and record their alignments accurately. They did so many things – so well!

And yet, questions remain…

How many shims do you see? Could the shim stack have been consolidated to reduce the number of shims? Could the thinner shims be “sandwiched” between the thicker ones so they would both be out of the way and not curl up like the ones in the photo? Could the flaking paint have been removed with a wire brush so it does not get between the shims–in essence becoming a partial, enamel shim? How much more work would it have been to go back to the shop, and cut a few pieces of ½” plate to use a one big shim under each motor foot?

You may be saying to yourself, “But you guys at VibrAlign don’t know how it is where I work!”

Yea, we probably do.

And we found out a long time ago that the extra ten minutes it takes it takes to get a few thick, clean, flat shims may well shave minutes, or even hours, off of the alignment process. It will minimize the risk of soft foot, increase your accuracy and repeatability, and cause you to tighten and loosen bolts much less.

Stacking the deck will get you in trouble!

About the Author

Stan Riddle joined VibrAlign in 2008. He has over 35 years experience in aligning industrial machinery. Stan received his AAS Degree in Machinist Technology from Surry Community College in Dobson, NC, and also holds a diploma in Industrial Systems Technology from Forsyth Technical Community College in Winston-Salem, NC, where he was also an instructor in the program.

Stan began his maintenance career working as a machinist and millwright for companies such as Weyerhaeuser, R.J. Reynolds, and Tyco Electronics. He also has over 25 years experience in Predictive Technologies, such as vibration analysis, thermography, oil analysis, and ultrasonic inspection. He is a certified Level III Vibration Analyst with the Vibration Institute, and is a Past Chairman and Board Member of the Piedmont Chapter.

Stan and his wife live in Yadkinville, NC.

4 responses to “Stacking the Deck Can Get You in Trouble!”

  1. Lambert Wang says:

    Hi Stan,

    I thought this kind of “stack up” problem will just happen in my plant only. Hummmm, no surprise right? It happens any where. I have few photos I took from our equipment recently and I can share with you if you give me the web link.
    Thank you,

    Lambert Wang
    Inteplast Group. Amtopp Div., PDM crew
    101 Inteplast Blvd., FM1593
    Lolita, TX 77971
    Tel: 361-874-3940
    Fax: 361-874-3974
    Email: lwang@amjk.inteplast.com

  2. Stan Riddle says:

    Lambert, we’d love to have the photos. I’ll email you directly.
    Thanks-Stan

  3. Rusty Castleman says:

    Unfortunately this is not just a “plant” problem. Skid-mounted machines often come from the manufacturer this way. I once did an alignment on a new compressor and apparently all they had was 0.005″ shims because each motor foot had over 20 shims under it!

  4. Rusty says:

    I also don’t like to see a mix of shims from different manufacturers (pick a brand and stick with it) and especially sizes – looks very unprofessional at the least. If it looks “right” then it’s more likely to be right.