Shaft Alignment Calculator

Shaft Alignment Calculator

This calculator will assist with shaft coupling alignments by determining the required motor foot moves from coupling alignment measurements. Use the calculator with diameter & face dial indicator readings or equivalent direct laser readings

A Simple Motor Foot Move Calculator

Instructions:

  • Measure the setup dimensions and enter them into the calculator. Face dia. is at indicator contact point.
  • Mount dial indicators on the outside diameter & front face of the movable machine coupling flange
  • Set both indicators carefully to zero at the top
  • Rotate each machine away and back to the top position to confirm reading repeatability
  • Now rotate both machines 180 degrees and read the dial indicators at the bottom position
  • Enter the bottom indicator values into the calculator (“+” dir’n is against indicator)
  • The displayed foot shim values shown in the yellow boxes are required to reach a true alignment
  • Positive moves are UP, negative moves are DOWN
  • Horizontal moves are calculated in a similar way from dial readings at 3 and 9 o’clock positions

Indicator sag may cause significant errors in this method, and depends on the length and rigidity of the dial indicator mounting bars. To compensate, it is necessary to measure total sag (TIR) using a rigid bar and enter this value in the sag input box. The calculator will compensate for this sag error.