Use Shaft Alignment Tolerances to help solve base- and bolt-bound situations. If, when performing an alignment, a base-bound or bolt-bound situation presents itself, take advantage of using the outer limits of your shaft alignment tolerances to help alleviate the situation. It may be possible to optimally position the machine so that the shafts may be misaligned, yet still remain within the required tolerances.
For example, a machine is horizontally bolt-bound at the inboard feet. It is currently well within its angularity tolerance, but just shy of satisfying the offset tolerance. A possible solution to get out of this situation is to try adjusting the offset by moving the back feet and pivoting the machine about the front feet so as to cause the offset to get a bit closer, while still maintaining the angularity tolerance. As long as the angularity remains within tolerance during this move to achieve the offset tolerance, this is a perfectly acceptable solution. Some laser alignment systems even allow you to test the effect of proposed moves without actually making them, thereby allowing you to determine if a proposed move such as the one described above will work, before you actually do the work of trying it. By evaluating the alignment situation objectively, and planning a move to remain within the tolerance limits of the alignment condition, you can avoid unnecessary moves, machining or hardware alterations to achieve the alignment.
Tip provided by: LUDECA, INC. ALIGNMENT * VIBRATION * BALANCING