When there is only one drawer in a carcass it generally runs directly on the bottom, and the top acts in place of kickers. In a similar way the cabinet sides are virtually the guides. When there are several drawers, or when the lower part is occupied by a cupboard, however, it becomes necessary to add separate runners, guides and kickers. The method of fixing these depends on the cabinet itself. For instance, the fixing in a cabinet with solid ends is rather different from that in one having paneled or plywood ends, because in the former allowance has to be made for shrinkage.
Solid end cabinets. A reliable method for these is given in Fig. 12. The mid-drawer rail is grooved at the back to enable a dust board to be fixed, but it incidentally provides a useful means of securing the runners, the front ends of which are stub-tenoned. When no dust board is required the groove is cut in locally to provide a mortise in which the stub-tenon can fit. The runners are grooved with the lough at the same setting then, when the stub-tenons are cut, it is merely necessary to make them line up with the groove.
The runners rest in grooves worked across the ends. This is essential for a really strong job because the grooves offer direct resistance to the downward pressure of the drawers. No glue is used far fixing, except possibly at the front because, in the event of shrinkage, the ends would be liable to split. At the back a screw is used, the wood being cut away to remove the groove and to enable the end to draw along the runner in the case of shrinkage, so avoiding splitting. The screw serves to hold the runner in place rather than to provide direct support. When the ends are of plywood or lamin board the runner can be glued throughout because there is no shrinkage problem.
The center fixing depends in a measure upon the kind of back being fitted. If there is a substantial mounting in the middle it is often possible to cut a groove across it and allow the back end of the runner to rest in this. If this is not practicable the simplest alternative is to introduce a hanger at the back. This can be conveniently dovetailed into the top rail. At the bottom it is again dovetailed, this time into the runner itself. The fixing at the front is by the stub-tenon as in the side runners. Both edges are grooved for dust boards, and the back dovetail is set in at each side sufficiently to clear the grooves easily.
How runners in winding prevent a drawer from working properly.
The guide is a plain square of wood glued and screwed directly on top. It is a good plan to make it slightly tapered in width to give easy clearance for the drawers. When there is a solid top to the carcase this prevents any tendency for the drawer to drop when opened. Sometimes, however, a couple of rails are substituted. This calls for the use of kickers. One only is needed because the rails are built out in their width at the ends and provide the necessary support. The strongest method is to frame the kicker between the rails before the last named are glued to the ends. For cheaper work a stub-tenon can be cut at the front only, the back being butted or fitted to an angled notch. There is sufficient give in the wood to enable the tenon to be inserted and the back pressed down.
The method for a framed-up cabinet is rather different, partly because there is no shrinkage to allow for, partly because it is not practicable to have grooves since the panels are thin. The mid-drawer rails are tenoned into the posts and are cut round them at the back so that the ends touch the panels. This not only makes a neat, strong job, but it provides support for the runners. The back edge is grooved for the dust-board as in the previous example, and the runners are stubbed into this. At the back the runners are screwed to the posts, but it is advisable not to rely on the screws safely—they inevitably allow of a slight movement. It is better to cut grooves.
This gives them a definite position and provides a strong bearing. The screw merely prevents the runner from pulling away. Note how the groove in the runner is cut away at the back to enable the screw to bed down. Since the panels are necessarily set well in from the inner face of the legs, guides are needed on top of the runners. The simplest method of fixing is to glue and rub them in position, and drive in screws after the glue has set. They must not be glued to the panels of solid wood.
The centre runner can be fixed to a hanger similarly to a solid upright. This forms part of the back framework and is notched to hold the runner. When fixing the latter the stubtenon at the front is inserted in the groove at an angle, and the whole thing pushed flat so that it enters the notch at the back. If the groove is shallow the wood will give enough to pass into the groove.
A bad fault to be avoided is that of winding runners. It is not always easy to detect because top and bottom runners may be the same distance apart throughout. It is clear, however, that if both runners at one side run upwards the drawer will bind. To test for this, rest a strip of wood with straight parallel edges across the back ends of the runners and look across the drawer rail towards it. If in winding it will at once be obvious.