Part 3

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 × 1-1/2-inch slot, as it calls for a 3/4-inch bolt, leaves a 3/4-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 1/4 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 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.

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.

IV

TRUING UP LINE SHAFTING

IT is assumed, for the purposes of this description, that the modern style of shafting, increasing in diameter by the 1/2 inch, is used, and that all pulleys and belts are in place. We will take a line composed of sizes ranging between 3-15/16 and 2-7/16 inches. This gives us four sizes, 3-15/16, 3-7/16, 2-15/16 and 2-7/16 inches in the line.

We will first consider the plumb-bob. The accompanying sketch, Fig. 47, illustrates a good one.

The ball is 1-1/2 inches diameter, and the large end of the tapered stem 1/2 inch in diameter, turned parallel for a short distance at the lower end. The two thin sheet-steel disks, 1 and 2 inches in diameter, are drilled to fit snugly when pushed on to the 1/2-inch part of the stem, and stay there until pulled off. These disks are turned true. This arrangement of plumb-bob and disks enables us to deal with five sizes on one line, and there are not many lines that contain more.

Now having our plumb-bob ready, we will stretch the line. The stretchers should be set horizontally by nailing a strip of wood, say 1 × 1-1/2 × 12 inches, with a piece at each end to form a space between it and the wall, or place of location in line with the edge of the shaft, as in Fig. 48. The top of this stretcher should be low enough to clear the largest pulley, and high enough to clear the hat of your tallest man. You would perhaps find it convenient to go between the spokes of a large pulley.

Now having located your stretcher, find approximately the position of your line, and drive a nail a foot or more below it in a vertical line, and another nail anywhere for convenient winding. The advantage of this plan is that the line can be easily adjusted as it merely passes over the stretcher, and is free to respond to movement either way; then when the final adjustment is made, and is ready for its final stretch, it is only necessary to pinch the line to the nail with one hand, while the other is at liberty to unwind, stretch and rewind the line without fear of its shifting.

The line being adjusted over the stretchers, we will now proceed to set it. Begin at the 2-7/16-inch end, by throwing your plumb line over the shaft and setting your line at that end, right with the _center point_ of your bob. Having done so, go to the other or 3-15/16 end of your line, and set the line so that the edge of the _ball_ of your bob just touches it. Now go back to the 2-7/16 end and see that the necessary adjustment did not alter it. Having proved this, give your line the final stretch and try if it is right at both ends. You now have a center line (though the edge instead of the center of the shaft is used) that may remain up for days if necessary without fear of disturbance.

It is best to go over the whole line first, before disturbing anything; so starting at the first hanger at the 2-7/16-inch end, throw your plumb line over the shaft, and record on the floor in chalk beneath it whether it is O. K. or wants to go either way, and how much; then go to the next hanger, and so on to the end. A short study of the conditions enables one to correct the faults, with a knowledge of the requirements, and consequently in the least time and with the least trouble.

Now suppose we start at the 2-7/16-inch end to inspect the line, we use the center point of the bob on the line so long as we are testing 2-7/16 inches.

When we get to the 2-15/16-inch part, which is 1/2 inch larger, we use the half diameter of the stem, the edge of which should just touch the line.

When we come to the 3-7/16-inch part, 1 inch larger than 2-7/16, we use the 1-inch disk, slip it on to the stem, and when it just touches the line with its edge it is O. K.

The 3-15/16-inch, being 1-1/2 inches larger than the 2-7/16-inch, will be right when the ball of the bob is in light contact with the line.

The 2-inch disk would be suitable for the next size, and other disks or modifications of the bob proper might be made to suit circumstances.

Now having straightened the line, the next process is to level it. As in some cases your pulleys will be too close to place your level where you want, make a light iron frame as per Fig. 49, making the suspending members of sufficient length to admit of your reading the level conveniently when standing on the floor. Hang your frame on the shaft, and put your level on the straight-edge below; in this way travel along the shaft, placing your frame where convenient. Be sure that one end of your frame does not rest on a shaft of different diameter, a key, keyseat, or anything to distort the reading.

Never be content with trying your level, especially an adjusting level, one way; always reverse it and try again; for if it is out of truth at the start, you might want to go through the roof or down cellar at the finish. Get into a habit of reversing your level, and so prove your work as you proceed.

V

APPARATUS FOR LEVELING AND LINING SHAFTING

THE first apparatus explained in this chapter was designed by the late Chas. A. Bauer, and is a highly perfected instrument.

For those who have lined and leveled shafting with an engineer's transit and level it is unnecessary to say anything of the advantages of that method over the cruder methods usually employed. It is not only done much more rapidly and economically, but the greater accuracy with which the work is done goes on paying dividends in decreased friction and loss of power and in lessening of wear.

The apparatus we now illustrate (Fig. 50) has at the top a hook, which is passed over the shaft, as indicated; on the straight portion of this hook are two sliding jaws which are so set that the shaft will just pass between them. Set into the face of this hook is a commercial 6-inch steel rule which facilitates the setting of the jaws, and they are of course so set that the tubular portion of the hook or leveling rod is centered vertically under the shaft. Within the outer tube, which is about 1 inch outside diameter and nicely japanned, is another tube, and inside this a third tube, these being arranged _à la_ telescope slide, and clamps being provided so that the length or distance from the shafting to the target may be anything desired from 4 to about 10 feet. At the lower end of the third or inner tube is a swiveling head to which the target is attached, and nurled nuts at this point give means of adjusting the sighting point of the target to the exact hight of the transit or level sighting line.

The target is a brass plate 5-1/2 inches diameter, on the face of which is a recess milled for the reception of a second commercial steel rule, which in this case is vertical and can be moved vertically and clamped in any desired position with reference to a line drawn upon the target. At the center of this scale is a very small hole through which the light of a hand flash lamp may shine to form the sighting point. The slot through the target at the right of the scale is provided with a single thickness of white cloth, which permits enough light to pass through it to help in finding the target in the field of the telescope.

The object of providing a vertical adjustment for the rule on the target is so that when passing from one diameter of shafting to another in the same line, as sometimes happens, the scale can be moved up or down just half the difference of diameter and the sighting point thus be kept at a constant hight.

The target is readily detached from the rod, and may then be placed upon the small standard (Fig. 51) which has at its base a V adapted to go over the shaft. The standard is tubular and the wire (about 1/8 inch diameter) may be adjusted and clamped at the desired hight. The target fits over the wire as shown (rear view of target) for leveling lines of shafting that may be near the floor, or, with the target removed, the V and wire form a sort of length gage or caliper with which the shaft may be made parallel to a line or wire stretched at the side of it. Two different lengths of wire are provided for this purpose.

The plumb-bob shown is part of the equipment and is a very superior article. A new feature it possesses is in having its larger portion hexagonal instead of round, so when laid down upon a plank or scaffolding it will lie there instead of promptly rolling off and falling to the floor. The entire apparatus is, we think, very well designed for its purpose.

TOOL FOR LEVELING SHAFTING

The instrument shown in Fig. 52 is a good one for use in leveling up shafting. It can be made to fit several sizes of shaft, or all the sizes ordinarily found in a factory.

When the instrument is placed on any piece of shaft and leveled up with the attached level, the plumb line will hang exactly the same distance from the shaft center every time. In this case the distance of line from center is 6 inches.

A handy apparatus for use in leveling up long lines of shaft can be made as follows.

Take two pieces of finished material, fasten together as in Fig. 53 and cut out as shown at _A_ and _B_ in Fig. 54. The opening _A_ is made so that the piece can be hung over the shaft, and the opening _B_ is made for the reception of a wooden straight-edge.

Make the straight-edge out of 1-1/4-inch stuff. Be sure that the edges are parallel, the width just enough less than the width of opening _B_, Fig. 55, to enter it, and the length 6 or 8 feet, to suit convenience. Use the apparatus with a level, as in Fig. 55, taking care that the suspension pieces are always on the same size shaft.

VI

SOME PRACTICAL KINKS[4]

A PULLEY on one of the motors at a certain plant had been giving some trouble by becoming loose and working its way along the shaft toward the motor bearing. Each time the pulley became loose, the set-screw was loosened, the pulley put back in position, the set-screw made tight and the motor started. After a few trials it was found that this would not prevent the pulley from working its way along the shaft. In order to overcome this difficulty the pulley was placed in its proper position, a line was drawn around the shaft close to the hub and, after the line was scribed, the pulley was removed and the shaft was burred upon the line as shown at _B_, Fig. 56. The pulley was then put back and driven close up to the burred line, the set-screw made tight and the pulley is now running without any apparent tendency to travel from its proper position. It will be seen that the position of the set-screw as indicated by the line at _A_ is a poor one and calculated to give plenty of trouble at the most inopportune time.

[4] Contributed to Power by Wm. Kavanagh.

Not long ago a cast-iron pulley had to move along a countershaft in order to make room for a pulley of another diameter. The pulley had not been on the shaft long, so it was thought that little work would be required to move it. A heavy bar was placed against the hub and a sledge hammer was used to strike the bar. After an hour and a half of heavy work the pulley was not moved over 1 inch (it had to be moved 16 inches), so it was suggested that a Bunsen burner be attached to a gas pipe by means of a hose and placed beneath the hub. The plan was immediately adopted. The burner was placed beneath the hub, the gas lit and allowed to heat the hub. After about twenty-five minutes it was found that a blow from the bar was sufficient to move the pulley. The pulley was moved the 16 inches inside of twenty minutes.

A very handy arrangement for moving pulleys is a bolt and nut. Fig. 57 shows the bolt and nut with a piece of pipe attached. A piece of pipe can be cut to suit the distance between the nut and hub of one pulley while the bolt head is against the other hub. The nut is screwed back upon the bolt as far as possible. A washer is then placed against the nut, and a piece of pipe cut to suit. Of course, the pipe must be large enough in diameter to fit over the bolt. If we screw back upon the nut, a powerful strain can be brought to bear between the hubs and in all probability the pulley will move.