In the engraving, a foundation is shown for a planer 48 x 48 inches x 18 feet. Fig. 160 is a vertical, longitudinal section of the foundation, and Fig. 161 is a plan. Substantial ground is supposed to have been found at a depth of five feet, and upon this the stone footings for the piers are laid, two and a half times the width of the stone cap, and a proportionate increase in the length of the piers. This stone footing is laid two feet deep, and upon it the brick piers are built with a "batter" of 2 inches to the foot.

In laying the bricks each course should be completed separately, and not by building a shell of one width of brick around the outside for several courses up at a time and filling in with brickbats and wide joints. In raising the comers not over three courses are built up, as cement mortar sets rapidly and it is very important that the work should be bound together as closely and strongly as possible.

Flush joints should be insisted upon in all machine foundation work. All piers should be capped with stone of fairly even thickness and perfectly level on the upper side.

In the center a pit is built as shown in the engraving. It should be six feet deep and extend from the pier beneath the rear of the side posts or housings, to a point far enough in front of the center gear to admit of free access to it in case of needed repairs. This pit should be wide enough to admit of placing in it wooden removable steps as shown.

On each side of the planer, pockets should be built for the pulleys, in case the planer is supplied with pulleys extending below the floor line. These pockets should be of such size as to permit the pulleys to be slipped on and off at the end of the shaft, and at least twelve inches wider than the diameter of the pulleys. In this case they are shown for a planer having pulleys on both sides.

Fig. 160. Vertical, Longitudinal Section of Planer Foundation.

As nearly in a vertical line with the cutting tool as may be are two hollow columns, usually made of heavy cast iron pipe, resting upon the brick floor of the pit, reinforced at these points by a large, well set stone. These columns support the planer bed at the two points, the weight being taken by heavy adjusting screws and a sole plate as shown.

A foundation of this kind should stand from five to ten days, according to its depth, after it is built, before the planer is placed upon it, in order that all mortar joints may be thoroughly set and perfectly hard and firm. The planer may be leveled up by steel wedges, lifting it about one quarter of an inch from the stone caps. The space around the resting places of the bed may then be closed with putty and melted lead poured in to give it a solid bed on which to rest, after which the steel wedges may be removed, leaving the weight upon the lead only. Melted brimstone is sometimes used, but its liability to crack from sudden jars renders it inferior to lead for this purpose.

In leveling up a planer, it is frequently the practice to level across the flat surfaces each side of the V's, or, if the table has been planed off when the planer was prepared for inspection in the shops, to place the level on that. The best plan, however, is to level up the bed before the table is put on. To do this properly, turn up three round pieces of steel whose diameter is such that as they lay in the V's of the bed they will project a half inch above its sides, and of a length equal to twice their diameter. These should be accurately ground to exactly the same diameter. (They may be made all in one piece and afterwards cut up if preferred.) Place them in the shaper and plane a flat place one half to three quarters of an inch wide on one side of each of them, and be sure that they caliper exactly the same across from the round surface to the flat space. Place one of these in each V, at one end of the bed, with the flat surface up. Lay on the parallel straight-edge and then the level, and bring the bed up to it. The third piece is then placed in one of the V's, the length of the straight-edge away from one of those already located.

Plan of Planer Foundation.

Fig. 161. Plan of Planer Foundation.

Now, level lengthwise. Transfer one of the other pieces to the V opposite the last one located and level crosswise again. Then from the last two level lengthwise, and so on the entire length of the bed. It may be necessary to go over the bed several times, never less than three times, but by this means a long bed may be leveled correctly and "out of wind." The time spent in accurately leveling up and setting a planer bed will be well spent when it comes to doing accurate work, and so saving many dollars in the usual expense of scraping work to fit on account of poor planing.

To have a planer so set up as to do really first-class work will save from 40 to 60 per cent of the usual scraping expenses, due to even fair work, besides the satisfaction of having a machine whose work can be depended upon.

The general principles here laid down should be followed in building the foundations for all classes of machine tools requiring a substantial foundation. And it should be remembered that in building such foundations they must be, first, of sufficient weight of material in proportion to the weight of the machine to be placed upon them to be able to withstand successfully all shocks and jars without injury, as well as to be capable of sustaining the weight of the machine without undue settling so as to throw the machine out of level or out of line in any part. And second, that the excavation is down to solid ground, certainly that all "made ground" or artificial filling is taken out; and that if the earth is still yielding, artificial support must be obtained as described in Part First for the foundations of buildings.