In industrial settings, rotating equipment such as pumps and motors demands exact alignment to operate efficiently around the clock. A frequent installation flaw—soft foot—occurs when machine feet fail to contact a flat foundation uniformly, or pipe strain exists, causing machine frame distortion that misaligns critical components such as bearing bores. This twisting or bending of the machine frame undermines the precision of machined internals, leading to vibration, wear, and inefficiency. Correcting soft foot is straightforward and vital, preventing these issues and ensuring long-term performance.
Why Flatness Matters: ANSI/ASA Guidance
Machine feet are designed coplanar and flat for stable mounting. Uneven bases introduce undesirable distortion. Per ANSI/ASA S2.75-2017, baseplate flatness (coplanarity) is paramount, requiring less than 2 mils of spacing between feet. Flatness directly affects shaft alignment; verify it first using a straightedge or dial indicator before installation.
Streamlined Correction Process
- Shim for Contact: Fill foot gaps with shims, limiting to 3–4 per foot for rigidity.
- Rough Alignment: Install the machine and achieve perform rough shaft alignment.
- Soft Foot Check: Use your laser alignment tool’s soft foot program, such as that in the intuitive Easy-Laser XT series, to provide clear graphical feedback on bolt adjustments. It identifies distortions in real time, guiding precise corrections without trial and error—this step is typically needed only once.
Valuable Resources
For practical insights, LUDECA’s free Soft Foot Find-and-Fix Infographic and 5-Step Shaft Alignment Procedure offer clear visuals and steps to implement effectively. These tools simplify detection and resolution, enhancing installation outcomes.
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Alignment by Daus Studenberg CRL