Rest _C_ on top of both shafts and at right angles to the driving shaft _B_. With _D_ pressed against _B_, place a square on stick _C_, as shown (stock in full contact with the top of the rod, and the tongue running down the side of it). Slide along _C_ toward _A_ until the side of the tongue touches the shaft the other side of _A_. Now mark a line on the stick down tongue. Do the same at the other end of your countershaft and the two resultant marks will be your parallel adjustment guides.
It often happens that a counter, or even line shaft, is end driven from the extreme end of the main or jack driving shaft with its other end running beyond the reach of the driving shaft, as shown in Fig. 32.
It is evident that neither method 1 nor 2 can here be applied to solve the alinement problem. If the driving pulley _B_ and the driven pulley _A_ are both in place, the following method can be used to advantage.
Fasten, or let somebody hold, one end of a line against pulley _B_'s rim at _B_^1; carry the line over to _A_ at _A_^2; now sweep the loose _A_^2 end of the line toward pulley _A_ until the line just touches pulley _B_'s rim at _B_^2. When the line so touches--and it must just barely touch or the measurement is worthless--_A_^1 and _A_^2 of pulley _A_ must be just touched by or (if _B_ and _A_ are not of a like face width, as in Fig. 32) equidistant from the line.
A single, two-hanger-supported length of shafting thus lined is bound to be in parallel; but where the so adjusted shaft line consists of two or more coupling-joined lengths supported by more than two hangers, only pulley _A_'s supporting portion of the shaft between its immediate supporting hangers 1 and 2 is sure to be lined; the rest may be more or less out.
To make a perfect job, fix a string in parallel with shaft length 1 and 2, stretching along the entire length of the adjusted shaft, and aline the rest of the shaft length to it.
When there are no pulleys in place to go by, or when, as occasionally happens, the wabbly motion of pulley _B_ (when running) indicates that, having been inaccurately bored or bushed, or being located on a sprung shaft length, its rim line is not at right angles to the shaft line, the method shown in Fig. 33 can be resorted to.