This article will help you take into account the critical points of everyone's favorite fantasy carpentry project before attempting to make it a reality. If you are considering building a door for a bookshelf or converting an existing bookshelf, study the challenge before diving in. That way you fully understand the physical requirements before you start sawing your wall open.
The biggest challenge is establishing a stable mechanical swing system – sufficiently robust to withstand years of use without showing the usual signs of fatigue and wear, while maintaining smooth and easy operation even when loaded with books.
The following step-by-step process will provide examples of calculations and measurements to give you a sense of what this takes. It only refers to a revolving door (opening to the person when facing the shelves), which is the most used version, and it is also right-handed, with the pivot on the right side of the door, but would work just as well with the hinges on the left.
Swinging bookcases tend to drop from the weight of the books, so they are often equipped with a wheel at the opening end to support the weight. But that solution will eventually leave a circular mark on the floor, and it is not very practical in a room with carpets.
Since it is almost impossible to hide the joints in the baseboard on each side of the bookshelf, it may be a good idea to build it higher from the floor to clear the baseboard, as illustrated in Figure 1. Our pictured version hangs on a robust swingable hinge, which in turn is mounted on a built-up block behind the base table.
The layout used here is for a door with a network opening of 40 ", but a larger housing that requires a wider opening can easily be used according to the same instructions. The design of the project will be drawn in the same way as old-fashioned floor layouts, with a plywood or other sheet longer than the doorway and no less than 16 inches wide, the case is 12 "deep.
wall and door opening
Step 1 – Size of door width
Line # 1 is the first one drawn and represents the existing wall and door where the bookshelf will be installed. It is pulled parallel to the front edge of the plywood and should be almost the entire length, and approximately 6 "from the rear from the front edge (Figure 2).
Step 2 – Size of Door Height
Line # 2 comes next and is drawn perpendicular to line # 1 on plywood at approximately 45-46 "from the left side (Figure 2). For this example only, line # 2 is the hinged side of the" hidden door ".
Step 3 – Sketch the strike
Measurement and marking 40 inches (see note below) back from line # 2, another perpendicular line (line # 3) is drawn parallel to line # 2 and will be called the Strike side of the hidden door.  * Note – If another opening or bookcase of different size in the plans, continue in the same way but make sure the plywood is large enough to accommodate.The opened bookcase takes up to 13-1 / 2 or more inches of the doorway.
Step 4 – Sketch the Jambs
D it is now time to sketch the door chambers on each side of the opening. They will be represented by the contours # 4 & # 5 in Figure 3, but will not necessarily have the same shape, thickness or proportions.
Adding the accessories to the layout
Step 5  – Sketching depth
When step 4 is completed, a rectangle (contour # 6 in figure 3) representing the net depth and the ideal impossible maximum width of the bookshelf, while respecting 1/4 ”Tolerance on each side to allow the case to be opened without to collide with debris. At the leading edge of each wall, a cut (contours 7 of Fig. 3) is laid 3-1 / 2 "to 4" wide and 3/4 "thick, and extending 1-1 / 4" across the opening, as shown in FIG. 3. The protruding portion will serve to cover the opening created by cutting off the excess material exceeding the release amount, as described by arc # 13 in Figure 5.
Calculate the Pivot location
The location of the pivot on the bookshelf must be far enough from all sides to provide sufficient strength, stability and power for the pivot hardware without breaking or breaking. crack. The use of a butt hinge, which is unfortunately only acceptable on an "Out" turn because it is impossible to hide, does not require any part to be cut out of the case at the hinge side, but everything on the strike side. Figure 5 shows the actual selected location with the corner cut for the 1/4 ”distance. If the placement of the pivot were moved back diagonally toward the center, it would only cause the side wall of the case to be moved in at the hinge side, at the same time resulting in a further increase of to be covered by the pruning.
Step 6 – Flat mounting element
Line 9 in figure 4 is added next. Pulling it on 1-3 / 4 ”from the front of the bookshelf leaves enough wood to provide proper fastening strength. Where line 9 crosses the hinged sidewall will be the intersection point or Axle # 10 and will be used as a starting point to trace arch # 11 with a radius of the combined 1-3 / 4 "(pivot backset) + 1/4" (tolerance) + 1-1 / 4 "(overlap of the face) giving up to 3-1 / 4". The intersection of that arch # 11 with 3-1 / 4 ”radius with line # 9 will give Axis # 12 and the center of the pivot site.
Step 7 – Plan the Gables
The backset of the two side panels can be determined by tracing the arches # 13 and # 14 using axis # 12 as the starting point (Figure 5). Extending a radius from that axis to the intersection of line # 9 with the right edge of the case, shows an arc traced to the leading edge 9/16 ”wide material that must be removed to get the proper distance at the opening case. This will cause the end plate to be moved 9/16 ”towards the center. Likewise and still from the same axis but with a radius extending all the way to the left edge of the case at the intersection with line # 9, the arc shows traced up to the rear edge of the case this time, showing that the gable must be moved 1-1 / 2 ”towards the center for to clear the tolerance required.
Step 8 – Plan the trim
Trim # 8 can now be added to the drawing to cover the back of the gable and ensure that the appearance of the finished product while closed is identical to the both sides. A reinforcing clamp large enough to fill most of the space while still clearing the door frame would give extra support and strength to the trim.