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.

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 1½ 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.

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 B¹; carry the line over to A at A²; now sweep the loose A² end of the line toward pulley A until the line just touches pulley B's rim at B². When the line so touches—and it must just barely touch or the measurement is worthless—A¹ and A² 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.

Instead of the nail used in methods 1 and 2, use a board about 8 to 12 inches long and of a width equal to considerably more than half of shaft B's diameter. By nailing this board x to the measuring rod c at any suitable angle, you will be enabled to reach from the end a well into the shaft B, as at b, and from b² well into A, as a². By keeping the board x along its entire length in full contact with the shaft B at both 1 and 2, the angular position of rod C is bound to be the same in both instances, and you will thus (by the use of a square, as in Fig. 31) be enabled to aline A parallel with B.

In all instances of parallel adjustment here cited it is assumed that both the alined and the alined-to shafts have been, as to secure accuracy of result they must be, properly leveled before starting to aline.

The above methods apply to cases where the shafting is already in place. Where, however, shafting is being newly installed before the work can be proceeded with, it is necessary, after determining on the location for the shafting, to get a line on the ceiling in parallel with the driving shaft to which to work to. Mark that point A which you intend to be the center line for the proposed shafting upon the ceiling (Fig. 34).

Rest your measuring rod upon the driving shaft and at right angles to it, with the nail against it. Hold your square with the stock below and the tongue against the side of the measuring stick, so that its tongue extremity touches the ceiling mark A, and then mark a line on the rod along the tongue side A. Move your rod along the driving shaft to the point where the other end of the proposed shafting line is to be, and, squaring your stick to the driving shaft with the tongue side A on the marked line of the stick, mark your section point on the ceiling. Draw a line or stretch a string between these points, and you have a true parallel to work to.

Owing to the supporting timber B's interference, a square had to be used; but where the ceiling is clear the rod can be cut to proper length or the nail be so located as to allow of using the stick extremity C for a marking point.

When a pulley is handily situated on the driving shaft, the method shown in Fig. 35 can be used to advantage.

Let somebody hold one end of a line at 1, and when you have got its other end so located on the ceiling that the line just touches the pulley rim at 2, mark that ceiling point (we will call it 3). In the same way get your marks 4 and 5, each farther back than the other and, for the better assurance of accuracy, as to just touching at 2, remove and readjust the line separately each time. If now a straight line from 3 to 5 cuts 4, your line 3, 4, 5 is at right angles to the driving shaft and a line at right angles to this will be parallel to the shaft.

The plumb-bob method is so familiar and, where not familiar, so easily thought out in its various applications, that we deem it useless to touch upon it.

The stringers or supporting timbers of drop hangers should be equal in thickness to about one-fifth of the hanger drop.

Where the stringers run with the hangers and crosswise of the shaft, both feet of a hanger base are bolted to the same stringer, and this should be from 1¼ to 1½ times the width of the widest portion of the hanger base. As the hanger is securely bolted to its stringer, this extra width is in effect an enlargement of the hanger base, and thus enables it the better to assist the shaft's end motion.

Where the stringers run with the shaft and crosswise of the hangers, the two feet of the hanger base are each fastened to a separate timber, and these should be equal in width to the length of one hanger foot, plus twice the amount of adjustment (if there be any) the hanger's supporting bolt slots will allow it. In reckoning hanger adjustment, be sure to figure in the bolt's diameter and to bear in mind that to get the utmost adjustment for the countershaft the bolts should originally be centered in the slot; thus a 13/16 à 1½-inch slot, as it calls for a ¾-inch bolt, leaves a ¾-inch play, and this play, with the bolt in the center of the slot, allows of 3/8-inch adjustment either way. Without this extra width addition any lateral adjustment of the hanger would result in leaving a part of the hanger's feet without stringer support. Such jobs look poorly, and often run still more poorly. Fig. 36, in its two views, will make the above points clear.

In the stringing of countershafts whose hangers have no adjustment it often happens, despite all care in the laying out, that they come 1/8 to ¼ inch out of parallel. A very common and likewise very dangerous practice at such times is to substitute a smaller diameter supporting bolt instead of the larger size for which the hanger foot is cored or drilled, and to make use of the play so gained for adjustment.

That shafting so carried does not come down oftener than it does is due solely to the foresight of the hanger manufacturers. They, in figuring the supporting bolt's diameter as against the strain and load to be sustained, are careful to provide an ample safety margin for overload, thus enabling the bolt substituted to just barely come within the safety limit under easy working conditions.

The largest-sized bolt that a hanger will easily admit should invariably be used, and for alinement purposes either of the following slower but safer methods should be used.

Rebore the hanger-supporting bolt holes in the stringers to a larger size, and use the play so gained for adjustment. It is not advisable, however, to rebore these holes any larger than to one and three-quarter times the diameter of the bolt to be used; and the diameter of the washers to be used on top of the stringers should be diametrically equal to at least twice the size of the rebored holes. That the washers used, under such conditions, must be of a good proportionate thickness goes without saying.

When the reboring method cannot be used—as when the hangers are carried by lag screws, lag-bolts, bolts screwed directly into supporting iron girders, etc.—it is evident that hanger adjustment can be secured by packing down one foot of the hanger base, as shown in Fig. 37.

The piece of packing (necessarily wedge-shaped) between the hanger foot B and the stringer A tilts the bottom of the hanger forward. The size of the wedge regulates the amount of adjustment. Wedge-shaped space D, at foot C, should also be packed out so as to avoid throwing undue strain upon C's extremity c. If now, the foot c of the countershaft's other supporting hanger (No. 2) be similarly and equally packed, as B of No. 1 hanger, the shaft will have been thrown forward at one end and back at the other, and thus into line. The equal division of the adjusting wedge packing between the opposite feet of the two hangers enables a limited packing to do considerable adjusting without any undue marring effect; and, further, insures the shaft's remaining level, which evidently would not be the case if only one hanger were packed down.

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 4¾ inches wide, placed 5¼ inches apart or 14¾ 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.

Where the building's beams run parallel to the shaft, Fig. 39, mark the counter's-center line A B, and then mark the spaces—as determined by the countershaft length, floor position of the driven machine or the driving point on the main shaft—to be occupied by the stringers C D, and, starting from the center line A B, cut outwardly each way to the desired beams 1 and 2.

Where the center line as laid out (before the position of the ceiling beams was known) brings it close to or directly under a supporting beam, it is generally advisable where possible to step the counter back or forward to a central position between the beams.

Where shafting is already in place in a building, no matter on what floor, valuable measurements as to beam location can thus be had from the plainly in sight and the reasonably deducible. Lacking in-place-shafting to go by, the walls, columns and main girders always clearly indicate the crosswise or parallel run of the ceiling beams to the proposed shafting line.

In the usual method of locating the timbers of a boarded-over ceiling, a brace and bit, or a nail, can be used for the purpose. If shy of an awl, and in preference the other two ways, force or drive a chisel (cold chisel or wood) in between a tongue and groove of the ceiling boards in stringer space (Fig. 38) E or F, and thus spring the boards sufficiently apart to insert a compass saw. With the extremity of a 12-inch saw a very little cutting (along the tongue and groove, as this shows least) will enable you to locate a beam, since they generally run 8, 12, 16, 20, 24 and 30 inches apart.

Always, on locating your beam, run the point of your compass saw down the whole of the timber's width, so that any nailed-on pieces will not lead you into a false estimate of the beam's thickness.

Figs. 40 and 41 make this point and its object clear. The saw, in Fig. 40, being stopped by A, naturally leads to the inference that A B is the timber's thickness. By running down the timber, as in Fig. 41, the saw's point sticking at a acts as a sure detector. This precaution should be taken on both sides (B and A) of the timber, and then, when the lags are screwed in, they can be sent home safe and true in the center of the timber.

It often happens that in boring for the lag screws the bit strikes a nail and further progress at that point seems out of the question. When so situated, take your bit out, and running the lag screw up as far as it will go, by sheer force swing it three or four turns up further than the point where your bit struck. Removing the lag and replacing the bit, it will be found that the nail has been forced aside and the way is now clear.

Hook bolts (Fig. 42) or—as our across-the-sea cousins call them—"elbow bolts," despite all assertions to the contrary, are an easy, safe and economical stringer fastener or suspending device.

Figs. 43 and 44 illustrate two very common abuses of the hook bolt. In the one (Fig. 43), instead of the bolt proper lying snug up against the beam flange with the whole of its hook resting squarely upon the beam's flange, its supporting countershaft is turned into a menace to limb and life by this "chance it" kind of erection. In the other (Fig. 44), though the bolts do lie snug against the flange, the hook being out of sight and no means being provided for telling whether the hook lies, as it should, at right angles to the web of the beam, even if properly placed at installation, timber shrinkage, vibration or a slight turn of the bolt when tightening the nut, all constitute dangerous factors tending to loosen or entirely loosen the hook's grip upon the beam flange.

Fig. 43 suggests its own remedy. As to Fig. 44, a screwdriver slot (made by a hacksaw) at the nut end of the hook bolt and running in the same direction as the hook, Fig. 45, will at all times serve to indicate the hook's position and, allowing as it does of a combined use of screwdriver and wrench, it can be used to prevent the bolt's turning when being tightened.

Where two or more hook bolts are placed close together on the same beam flange, a plate, preferably wrought iron with properly spaced confining pins for the hooks, may be placed between the beam flange and the hooks as in Fig. 46. Its benefits are obvious and so likewise is the use of a small, square, wrought-iron plate with a bolt hole through its center instead of hook bolts.

The various styles of beam clamps carried by the hardware and supply trade all have their good points, and though the C of their cost may seem to loom large, it is not a whit more emphatic, taken all in all, than the W of their worth.

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