... alignment 10 Alignment parameters 10 Angularity, gap and offset 11 Short exible couplings 14 Spacer shafts 15 How precise should alignment be? 18 Alignment tolerances 18 Troubleshooting 21 Coupling ... indicators (reverse indicator, rim and face, double rim for example) the comparison of measurements and the application of tolerances can be problematic. Additionally the fact that rim indicator ... a very long, exible shaft begins to rotate, the bow of the shaft tries to straighten out, but will never become a perfectly straight line. It is important to understand that the axis of rotation...