ENGINEERS, machinists and general mechanics are often called upon to turn their hands to a shafting job. We recognize that all of the following cannot prove new or even suggestive to most of our readers; still, some of it for all, and, mayhap, all for some, may not come amiss.
[3] Contributed to Power by Chas. Herrman.
We all know that to have belting run rightly on pulleys located upon parallel lines of shafting the shafting must be in absolutely correct parallel. The slightest deviation, even to a 1-16 inch, often imparts a marring effect, through poorly running belts, to an otherwise faultless job.
Fig. 30 shows how to line a countershaft as regards parallelism with the driving shaft when the countershaft's end-centers are availably situated for thus measuring. _A_ is the countershaft, _B_ the main shaft, _C_ is a stick of proper length about 1-1/2 inches in thickness and width, _D_ a heavy nail--about 20-penny will do--driven into _C_ far enough from its end _E_ to allow of _C_'s resting squarely upon the top of the shaft _B_.
Rest the measuring rod upon the main shaft, keeping the nail in touch with the shaft, so that when the _F_ end is in contact with the end of the countershaft the stick shall be at right angles to the main shaft, and then mark the exact location _a_ of the countershaft's end-center on the stick. Do the same at the other end of the countershaft. If both marks come at the same spot, your counter is parallel; if not, space between these two marks will show you how much and which way the counter is out.
It may only be necessary to shift one end in or out a little; and then, again, it may be that to get into line you will have to throw one end all the way in one direction and the other all or some in the opposite direction. But, whichever it be, do not rest content until you have verified the correctness of your adjustment by a re-measurement.
The nail should be well driven into _C_, so that its position will not readily change, and it should, preferably, be slant driven (as shown in Fig. 30), as it thus helps to keep the stick down in contact with the shaft.
Where an end-center is not available or where there is no clear space on the main shaft, opposite a center, the method shown in Fig. 31 can generally be used.