Describe the basic steps to align two shafts using dial indicators.

Describe the basic steps to align two shafts using dial indicators.

• A. Align by eye and then recheck with a dial indicator.
• B. Attach indicators to measure runout, check for soft foot, adjust using shims to bring indicators within tolerance, recheck alignment.
• C. Tighten both shafts until they are hard to move.
• D. Replace bearings and start over.

Answer: (B)

Measuring with dial indicators turns misalignment into numbers you can correct. Start by mounting the indicators so their probes contact stable reference points on the shafts or their mounting surfaces, then rotate the shafts to read runout and the relative position of the two shafts. Check for soft foot—the condition where the machine base or mounting surface isn’t flat, so tightening bolts changes the readings. If soft foot is present, add or remove shims under the feet until readings stay consistent within the specified tolerance. With the readings within tolerance, adjust the mounting (often by trimming shims or nudging the components) to bring the shafts into proper alignment in both the horizontal and vertical directions, then recheck through a full rotation to confirm stability. Finally, tighten all fasteners and reverify. Eyeballing the alignment isn’t precise, and forcing tightness won’t reliably fix misalignment, while replacing bearings is not part of the alignment process.

Measuring with dial indicators turns misalignment into numbers you can correct. Start by mounting the indicators so their probes contact stable reference points on the shafts or their mounting surfaces, then rotate the shafts to read runout and the relative position of the two shafts. Check for soft foot—the condition where the machine base or mounting surface isn’t flat, so tightening bolts changes the readings. If soft foot is present, add or remove shims under the feet until readings stay consistent within the specified tolerance.

With the readings within tolerance, adjust the mounting (often by trimming shims or nudging the components) to bring the shafts into proper alignment in both the horizontal and vertical directions, then recheck through a full rotation to confirm stability. Finally, tighten all fasteners and reverify.

Eyeballing the alignment isn’t precise, and forcing tightness won’t reliably fix misalignment, while replacing bearings is not part of the alignment process.