Dimensions
Tips for the Cabinet Case
Tips for Drawer Construction
Tips for Drawer Runners
Basic woodworking and joinery skills are assumed, not only in order to construct the cabinet, but also in order to understand these instructions. Basically, the cabinet and drawer construction themselves are quite straightforward, but there are some complexities in relation to the drawer runners which affect the drawer construction.
For you to understand the tips related to drawer runners, you must first read the definitions of the cabinet profile and the drawer profile in the previous section (Designing the Cabinet - What to Consider), and also have a set of these runners in front of you so that you understand clearly how they work.
Dimensions
Your cabinet and drawers will likely have different dimensions from mine, but here are my own measurements:
The cabinets are built with what is known as simple box construction, as opposed to frame and panel construction. Each of the two cabinets is 26 1/2” wide, 36 1/2” tall, and 23 3/4" deep. They are made with 3/4” oak ply using iron-on edging veneer, with a 1/4” hardboard back panel measuring 25 3/4” by 35 3/4”.
The drawer fronts are 3/4” solid oak, 24 7/8” wide by 2 3/16” tall. The drawer backs are 1/2” MDF, 23” long by 1 1/4” tall. The drawer sides are also 1/2” MDF, 22 3/4” long by 1 3/4” tall, but tapered in the back 6” down to 1 1/4” to facilitate removal. The drawer bottoms are 1/4” hardboard, 24” wide by 22 3/4” deep.
Horizontal strips are 1/4” hardboard, 23 1/4” by 5/8”. The single-extension drawer runners are 22” long. Each solid oak handle is 1” deep, 1 1/2” tall, and 3” long.
Further dimensions (e.g. for rabbeting) are provided under the following subtopics, and assume that you are using materials of the same thickness as those I used.
Tips for the Cabinet Case
Dimensions neatly divisible into four or eight feet will minimize wastage in the sheets of plywood, MDF, and hardboard that you buy. In otherwise, you can decide to maximize your cabinet size to minimize wastage. (But in doing so you also have to consider the sizes of the drawer bottoms, sides, etc.)
Plywood and other man-made sheets are not always flat. A warped sheet can cause an inwards or outwards bow in your cabinet top, bottom, or sides. This can be somewhat corrected at the back through the hardboard used as the back piece, but there is nothing at the front to help bring the warp into line. Side-mounted drawer runners require 1/2” of space at each side. A very minor warp in the cabinet sides will squeeze or stretch the runner mechanisms. Avoid the problem by using flat material, or by aligning minor warps concentrically.
For my purposes I find that butt joints with 2 1/2” wood screws are sufficient for cabinet assembly. Set the screwheads in about 3/16”, concealing them with wooden plugs. The squareness and rigidity of the cabinet frame will be near-perfect after you’ve glued and nailed the back panel into a 1/4” x 3/8” rabbet routed in the back of the case.
Tips for Drawer Construction
Use mass-production techniques for the drawers, but note that it’s worthwhile building and fitting two prototype drawers before cutting and assembling the rest. You’ll then know whether your measurements are right, how well the drawers fit fit, how the drawer runners work, how well one drawer clears another when it’s removed.
Rabbet each drawer front 1/4” high by 3/8 deep” to attach and conceal the bottom. This is for nesting the drawer bottom and allow it to be nailed and glued to the drawer front. The drawer back does not need to be rabbeted because the drawer bottom is butted to the drawer back from below.
Also, rabbet the inside ends of the drawer front 15/16" from the ends. These rabbets nest the drawer sides, allowing them to be nailed and glued to the drawer front (they will be butted against the drawer back, just as the bottom was). But in doing so ensure the central section of the drawer is precisely the intended inside drawer width, so that you don't have too much or too little space at the sides for the drawer runners. The 15/16" consists of the 1/2" thickness of the drawer sides and the 1/2" required for the drawer runners, minus 1/16" so that the sides of the drawer front will have a little clearance from the cabinet frame.
If you intend to use grooves to house horizontal strips, route them before your sheet is sliced in the opposite direction into drawer side pieces.
Side-mounted runners require that to be removed, the drawer-side roller must ride over the cabinet-side roller. At this point, the drawer rises vertically by 3/4”. To allow clearance, the top of the drawer sides should be 1/4” lower than that of the drawer front, to avoid obstruction by the drawer profile above. Consider that to be Allowing for Drawer Removal 101.
OK, if you understand that, now here's Allowing for Drawer Removal 201: Unless the drawer-side roller protrudes beyond the drawer back, the drawer back and the back portion of the drawer sides must be shaped a further 1/2” lower. This is the tapering referred to above under the dimensions heading, because my drawer sides are longer than my 22" runners. (I chose to taper those depressions, but you could instead use step-down depressions). The greater the distance from the drawer-side roller to the back of the drawer, the longer the depression needed in the drawer side. You might need to get some hands-on experience to understand this.
Assemble the drawers upside-down, using a 1/4” spacer board on the workbench to raise the drawer sides and back to the level of the drawer front. Nail and glue all parts, pre-drilling to avoid splitting the wood. MDF splits very easily.
Plan on a 1/16” gap between each drawer front and the ones above and below it. (If you rabbeted correctly, you have already allowed for this). Also plan on a 1/16' gap between the cabinet case and the adjoining drawers. When testing the fit of your completed drawers, you’ll find that reality differs from theory. If drawers are misaligned, you’ll have to tweak them. The simplest method to get uniform gaps is to sand down oversized sides of the drawer fronts. There are other ways. You can take advantage of the adjusting screw positions in the cabinet profiles. Or, to raise one side of a drawer, place a washer between the drawer bottom and the drawer profile. As each drawer will fit best in its intended position, number each drawer on the inside.
To make your own drawer handles, use a half-round bit to route finger-depressions in strips of 1” x 1 1/2” wood, and then cut to 3” lengths. Use two screws to mount each handle. Drill screw holes accurately to match the positions of the holes in the drawer fronts.
Tips for Drawer Runners
Very carefully measure and lay out the screwing positions for the cabinet profiles on the inside cabinet sides, recheck measurements, recheck again, and then mount them before assembling the cabinet. Screw holes are provided for #6 or #7 screws (your choice). You don't need to use all screw positions, and in fact it's best if you don't, because adjustments can be made by using different screw positions. But make sure you use the front screw position, in order to fully support the weight.
If a screw head protrudes and obstructs movement of a drawer-side roller, replace the offending screw with another screw in an alternate hole.
The cabinet profiles have short flanges protruding up and down at the front. The longer flange is the up side, and the shorter flange goes down. For the lowest drawer, the short flanges may need to be filed down to minimize the gap height below that drawer.
When attaching the drawer profiles to the drawers, use the screw holes in the bottom of the profile, screwing upwards through the drawer bottom and into the side pieces. Do not use the side screwing positions in the drawer profiles.
For further information, a PDF document for single- and full-extension Standard runners is available from www.blum.com.
Above All
Plan in detail, and double-check all calculations. Before cutting, check all measurements.
Ensure that the tablesaw is precisely aligned. A small discrepancy from 90 degrees in the blade angle, or misalignment of the miter gauge or table fence may magnify itself in the shape of the finished project, resulting in out-of-square cabinets and drawers.
