After so adjusting, be sure to get your hangers squarely crosswise of the shaft as readjusted, so that the hanger bearings will lie in a true line with the shaft and not bind it. At all times be sure to have your hangers hang or stand plumb up and down; as, if the bearings are not so pivoted as to be horizontally self-adjusting, excessive friction will be the lot of one end of the bearing with not even contact for the rest of it. The bearing being self-adjusting all ways, square crossing of the shaft line by the hanger line and plumb still remain eminently desirable for appearance's sake.
Before a countershaft can be put up on a ceiling whose supporting timbers are boarded over, or in a modern fireproof structure whose girders and beams are so bricked and plastered in as not to show, it is necessary to positively locate those of them which are to carry the stringers.
It is in the earnest endeavor to properly locate these that the unaccustomed hand turns a wood ceiling into a sieve and a brick one into a wreck. To avoid kitchen and house razing effects, try the following recipe:
We will assume that line _A B_, Fig. 38, laid out by one of the methods previously described, is the center line of the proposed countershaft. The hanger's base length, lateral adjustment and individual foot length call for stringers 4-3/4 inches wide, placed 5-1/4 inches apart or 14-3/4 inches outside (as per sketch). The floor position of the machine to be driven, or the driving point of the main shaft, is so located with reference to the countershaft that one of the supporting hangers must go at or very near _C_, and the countershaft's length brings the other hanger at or very near _D_.
Now between points _C D_ and with due reference to the center line _A B_, lay out the position which your stringers are to occupy. It is self-evident that by confining your beam prospecting to the stringer spaces _E_ and _F_, ultimately, when the countershaft is in place, all the cut-up portions of the ceiling will be hidden from view.
Generally the necessary supporting beams will not all be found within the shaft's length distance _C D_; in such cases continue your cutting in the same parallel line to _A B_, as at _E_ or _F_, going from _C D_ outwardly until you strike the sought-for beams. Having located beams, say 1 and 2, we find by measurement that they are 5 feet apart, and, as beams are generally uniformly spaced, we may start 4 feet 6 inches (go 4 feet 6 inches and not 5 feet, to make sure not to skip beam 3 and thus make a cut that will not be covered by the stringers) from 1 to cut outwardly for the location of beam 3.