If the bed rests upon a foundation at several points in its length it should be rested at those points while being fitted and carefully levelled as before, the template and spirit-level being tried at every two or three feet of the bed length.

To test the width of the V’s and their widths apart in the fitting, the template a b, [Fig. 2570], must be used in connection with red marking, but to true the lengths of the ways a surface plate about 4 feet long and slightly wider than the width of one side of the ways must be used, and if the template and the surface plate show the ways true they will be of the correct width, of correct angle and true planes. But this does not insure that the two ways are in line one with the other, and for this purpose separate test blocks are necessary, because the template is too narrow in width to give a good test, and cannot be made wider, because in that case its own weight would cause it to spring or deflect to suit any error in the work.

Fig. 2571.

These test blocks are simply two pieces of metal, such as shown in [Fig. 2571]. The lengths of these blocks should be about 8 inches, and the best way to obtain them true and exactly alike is to make one block and then cut it into two. They possess an advantage not possessed by a template that spans both ways, inasmuch as they may be turned end for end in each way and thus test the accuracy of the angles of each way.

Again, both may be placed in one way, and by various applications in connection with straight-edge, surface plate, and level they will test the truth of the ways, both individually and one with the other in a better manner than by any other method.

VOL. II.TESTING PLANER BEDS AND TABLES.PLATE XI.
Fig. 2572.
Fig. 2573.Fig. 2574.
Fig. 2575.Fig. 2576.
Fig. 2577.

[Fig. 2572] represents the various positions of the V blocks for the testing, a, b, c, d, e, f, g, h, representing the blocks; straight-edges may be placed as at i, at j, and at k, and if the ways are true the straight-edge, lightly coated with marking, should have contact clear across the upper surface of both V-blocks, and a spirit-level placed on the straight-edge (in each position of the same) should show them to be level.

The surface p, on which uprights or standards on that side of the plane, rest, being planed with the V-ways will be true with them, and the uprights may be erected thereon, their base surfaces being fitted to p until the standards stand truly vertical and parallel in their widths apart. In testing these uprights they should be bolted home as firmly as they will be when finally erected, as they will be liable to alter their set if bolted up more firmly than when tested. These front surfaces should be at a right angle to the length of the bed V-ways, and this may be tested by placing a straight-edge across their surfaces and testing it with a square rested against the edge of the planer table.