Tab-and-slot spice shelf

Source 62 lines

// Spice shelf: a wall shelf held together by tabs and slots, no glue or
// screws in the joints. The shelves and their front rails tab into the
// sides, and the sides tab into the back, which hangs on two screws by
// its keyholes.
 
use <kerf/tabs>
use <kerf/hanging>
 
/* [Shelf] */
// Outside width
width = 260; // [120:10:500]
// Outside height
height = 240; // [120:10:500]
// Depth from the wall
depth = 70; // [40:5:150]
// Number of shelves
shelves = 2; // [1:1:5]
// Height of the rail in front of each shelf
rail = 22; // [0:1:40]
 
/* [Material] */
// Sheet thickness, measured
$thickness = 3; // [2:0.5:6]
// Beam width
$kerf = 0.15; // [0:0.01:0.3]
// Added to every slot, for an easy fit
clearance = 0.1; // [0:0.05:0.3]
 
/* [Hidden] */
$material = "plywood";
t = $thickness;
// The back reaches past the sides, so their slots are closed all round
inset = 6;
// Between the sides, and out from the back
span = width - 2 * inset - 2 * t;
reach = depth - t;
// Where each shelf's underside is, the lowest one 10 mm up
levels = [for (i = [0:shelves - 1]) 10 + i * (height - 40) / max(1, shelves)];
// Where the rails stand, measured on a side from the back
rail_at = reach - 1.5 * t;
 
part("back", at = [0, t, 0], rotate = [90, 0, 0])
  keyholes(span / 2, at = [width / 2, height - 18]) difference() {
    rect([width, height], r = 4);
    for (x = [inset + t / 2, width - inset - t / 2]) translate([x, 0]) rotate(90) slots(height, clearance = clearance);
  }
 
part("side", qty = 2, rotate = [90, 0, 90], at = [[inset, t, 0], [width - inset - t, t, 0]]) difference() {
  tab_rect([reach, height], [false, false, false, true]);
  for (z = levels) {
    translate([0, z + t / 2]) slots(reach, clearance = clearance);
    if (rail > 0) translate([rail_at, z + t]) rotate(90) slots(rail, clearance = clearance);
  }
}
 
part("shelf", qty = shelves, at = [for (z = levels) [inset + t, t, z]])
  tab_rect([span, reach], [false, true, false, true]);
 
if (rail > 0)
  part("rail", qty = shelves, rotate = [90, 0, 0],
    at = [for (z = levels) [inset + t, t + rail_at + t / 2, z + t]])
    tab_rect([span, rail], [false, true, false, true]);