For the field portion of a recent training class, the decision was made to check the alignment on a plastic extruder. At first glance, checking the alignment of the motor shaft to gearbox input shaft is pretty straightforward. However, the output side of the gearbox had two shafts, so maybe this is not so straightforward. And to complicate things a little more, there are three more chambers coupled together for a total of four sets of couplings.
A little intimidating for someone that may be new to precision shaft alignment!
So we needed to simplify things if possible. I could not get a topical photo of the extruder, so here is a sketch of how we approached this alignment.
The decision was made to make the highlighted shafts collinear. Once this was verified, verification that the other shafts were collinear would then take place. The final result? 0.3mil (0.0003”) out of tolerance for the entire machine.
In my humble opinion, pretty darn good!