1. Soft Foot Diagnosis & The Soft Foot Wizard

2. Detection vs. Correction
The amount of Soft Foot detected does not equate to the required Soft Foot correction!

3. Some Types of Soft Foot Rocking (Highest values diagonally opposed.)
Angled (Bent foot; bowed baseplate, angled soleplate.)
Squishy (Too many shims, dirt, etc.)
Induced (External forces: Pipe strain.)

4. Rocking Soft Foot (highest values diagonally opposed)
Some Types of Soft Foot
Rocking Soft Foot (highest values diagonally opposed)
Three types:
Short foot rocking soft foot:
Parallel airgap under foot with largest soft foot reading.
Tapered airgap (inwards) under diagonally opposite foot.
Even Rocking soft foot:
Inward tapers under both diagonally opposite soft feet.
High Foot rocking soft foot:
Outward tapers under both diagonally opposite soft feet.
Larger soft foot value on foot nearest the high foot.

5. Soft Foot Diagnosis
The type of soft foot can usually be determined by comparing the measured values.
Different types of Soft Foot yield different combinations of values.
Diagnosis and correction is expedited by recognizing the type of soft foot problem, then seeking appropriate additional data required to solve it.

6. Diagnostic Process
Number inside circle represents a laser soft foot reading. 12 10 6 3
Number in parentheses represents a shimming correction to make. 20
(Step Shim) 16 8
Numbers in the corners of each foot represent feeler gauge value of the air gap measured. 25
Arrow represents direction of taper of airgap, from highest to lowest.

7. Rocking Soft Foot
Imagine this condition on your machine. The front right foot is short. If you tighten the anchor bolt, the foot will bend until it can’t bend any more. Then, if you continue tightening the anchor bolt, you’ll either break the foot off, or distort the rest of the machine frame. If the foot does not break off...

8. Rocking Soft Foot
Suppose the short foot is now tight to the base. The frame is distorted and under stress. How will that stress relieve itself as you loosen each of the anchor bolts in turn, always with the others tight? Obviously, the short foot will come up as fast and as much as you allow it to, if you loosen its bolt.

9. Rocking Soft Foot
On the other hand, if the short foot is tight, the opposite corner (the back left foot) will also come up if you let it. So the machine “rocks” diagonally. Now imagine for a moment what the air gaps under each of these feet will look like, if you loosen these feet...

10. Rocking Soft Foot
Laser system indicates Soft Foot values greater than 2 mils at diagonally opposite corners. 15 15 12 9 12 14 1 2

11. Short Foot Rocking Soft Foot
Please view our QuickTime video on rocking soft foot in action... Available as a separate download from our Learning Center page.

12. Induced Soft Foot
Laser tools will show soft foot values on two, three or even all four feet of the machine. The two highest values tend to be along the same side or the same end of the machine frame.
The distribution pattern of the values does not match any angled soft foot patterns.

13. Induced Soft Foot
Laser tools will show soft foot values on two, three or even all four feet of the machine. The two highest values tend to be along the same side or the same end of the machine frame.
If you suspect pipe strain, the Optalign Smart will let you check for that and quantify its impact on the shaft alignment, so you can take this information to the pipe fitters as proof of the problem...
The distribution pattern of the values does not match any angled soft foot patterns.

14. The Soft Foot Wizard

15. Laser Alignment Systems
Rotalign Ultra is ideal for soft foot because:
It has a high resolution sensor for accurate detection.
It will diagnose the problem and suggest a solution for it.

16. Diagnosis: Example with Laser

17. Example Diagnosis

18. Example Diagnosis: Rocking Soft Foot found

19. Diagnosing the Solution

20. Diagnosing the Solution

21. Diagnosis & Solution Finished

22. Diagnosing the Solution
An Angled Soft Foot Problem

23. Diagnosing the Solution
An Angled Soft Foot Problem, cont.

24. Conclusions Soft Foot diagnosis & correction is always a challenge.
Consistently accurate Soft Foot diagnosis is possible.
Rotalign® Ultra makes this a breeze!

25. Thank you!