Box shelves now have screws in the corners to hold them down.

printed/box.scad

@@ -474,16 +474,19 @@ function subst_sheet(type, sheet) =
     let(s = box_sheets(type))
         sheet ? assert(sheet_thickness(sheet) == sheet_thickness(s)) sheet : s;
 
-module box_shelf_blank(type, sheet = false) { //! Generates a 2D template for a shelf sheet
+module box_shelf_blank(type, sheet = false, wall = undef) { //! Generates a 2D template for a shelf sheet
     difference() {
         sheet_2D(subst_sheet(type, sheet), box_width(type) - bezel_clearance, box_depth(type) - bezel_clearance, 1);
 
         offset(bezel_clearance / 2)
             box_corner_quadrants(type, box_width(type), box_depth(type));
+
+        box_shelf_screw_positions(type, [], 0, wall)
+            drill(screw_clearance_radius(box_shelf_screw(type)), 0);
     }
 }
 
-module box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = undef) { //! Place children at the shelf screw positions
+module box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = undef, top_screws = true) { //! Place children at the shelf screw positions
     w = is_undef(wall) ? box_wall(type) : wall;
     insert = box_shelf_insert(type);
     translate_z(-insert_boss_radius(insert, w))
@@ -491,13 +494,22 @@ module box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = un
             multmatrix(p)
                 translate_z(thickness)
                     children();
+
+    r = box_boss_r(type);
+    inset = box_intrusion(type) - r + (r + insert_boss_radius(insert, w) + bezel_clearance / 2) / sqrt(2);
+    if(top_screws)
+        translate_z(thickness)
+            for(x = [-1, 1], y = [-1, 1])
+                translate([x * (box_width(type) / 2 - inset), y * (box_depth(type) / 2 - inset)])
+                    rotate(45 * x * (2 + y))
+                        children();
 }
 
 module box_shelf_bracket(type, screw_positions, wall = undef) { //! Generates a shelf bracket, the first optional child is a 2D cutout and the second 3D cutouts
     w = is_undef(wall) ? box_wall(type) : wall;
     insert = box_shelf_insert(type);
     lip = 2 * insert_boss_radius(insert, w);
-    width = insert_length(insert) + w;
+    width = max(insert_length(insert) + w, lip);
 
     module shape()
         difference() {

printed/butt_box.scad

@@ -51,9 +51,10 @@ function bbox_name(type)       = type[8]; //! Optional name if there is more tha
 function bbox_skip_blocks(type)= type[9]; //! List of fixing blocks to skip, used to allow a hinged panel for example
 function bbox_star_washers(type)= type[10];//! Set to false to remove star washers.
 function bbox_thin_blocks(type) = type[11];//! Set for 2 screw blocks instead of three hole fixing blocks.
+function bbox_short_inserts(type)= type[12];//! Set to use short inserts in the blocks
 
-function bbox(screw, sheets, base_sheet, top_sheet, span, size, name = "bbox", skip_blocks = [], star_washers = true, thin_blocks = false) = //! Construct the property list for a butt_box
- [ screw, sheets, base_sheet, top_sheet, span, size.x, size.y, size.z, name, skip_blocks, star_washers, thin_blocks ];
+function bbox(screw, sheets, base_sheet, top_sheet, span, size, name = "bbox", skip_blocks = [], star_washers = true, thin_blocks = false, short_inserts = false) = //! Construct the property list for a butt_box
+ [ screw, sheets, base_sheet, top_sheet, span, size.x, size.y, size.z, name, skip_blocks, star_washers, thin_blocks, short_inserts ];
 
 function bbox_volume(type) = bbox_width(type) * bbox_depth(type) * bbox_height(type) / 1000000; //! Internal volume in litres
 function bbox_area(type) = let(w =  bbox_width(type), d = bbox_depth(type), h = bbox_height(type)) //! Internal surface area in m^2
@@ -78,7 +79,8 @@ function corner_block_positions(type) = let(
           rotate([z > 0 ? 180 : 0, 0, corner * 90 + (z > 0 ? 90 : 0)])
     ];
 
-function corner_holes(type) = [for(p = corner_block_positions(type), q = corner_block_holes(bbox_screw(type))) p * q];
+function corner_holes(type) = let(short = bbox_short_inserts(type))
+    [for(p = corner_block_positions(type), q = corner_block_holes(bbox_screw(type), short_insert = short)) p * q];
 
 function fixing_block_positions(type) = let(
         width = bbox_width(type),
@@ -112,7 +114,8 @@ function fixing_block_positions(type) = let(
 
 function side_holes(type) = let(
     screw = bbox_screw(type),
-    holes = bbox_thin_blocks(type) ? 2screw_block_holes(screw) : fixing_block_holes(screw))
+    short = bbox_short_inserts(type),
+    holes = bbox_thin_blocks(type) ? 2screw_block_holes(screw, short_insert = short) : fixing_block_holes(screw))
         [for(p = fixing_block_positions(type), q = holes) p * q];
 
 module bbox_drill_holes(type, t)
@@ -232,6 +235,7 @@ module _bbox_assembly(type, top = true, base = true, left = true, right = true,
     tt = sheet_thickness(bbox_top_sheet(type));
     star_washers = bbox_star_washers(type);
     thin_blocks = bbox_thin_blocks(type);
+    short = bbox_short_inserts(type);
 
     function is_missing_screw(p) = p.y > depth / 2 - 1 ? !back : false;
 
@@ -241,14 +245,14 @@ module _bbox_assembly(type, top = true, base = true, left = true, right = true,
             let(q = transform([0, 0, 0], p), thickness = q.z > 0 ? tt : bt)
                 multmatrix(p)
                     fastened_corner_block_assembly(is_missing_screw(q) && ((q.z > 0) != (q.x > 0)) ? 0 : t, bbox_screw(type), thickness,
-                                                   is_missing_screw(q) && ((q.z > 0) == (q.x > 0)) ? 0 : t, star_washers = star_washers);
+                                                   is_missing_screw(q) && ((q.z > 0) == (q.x > 0)) ? 0 : t, star_washers = star_washers, short_insert = short);
 
         h = height / 2 - 1;
         for(p = fixing_block_positions(type))
             let(q = transform([0, 0, 0], p), thickness = q.z > h ? tt : q.z < -h ? bt : t)
                 multmatrix(p)
                     if(thin_blocks)
-                        fastened_2screw_block_assembly(is_missing_screw(q) ? 0 : t, bbox_screw(type), thickness_below = thickness, star_washers = star_washers);
+                        fastened_2screw_block_assembly(is_missing_screw(q) ? 0 : t, bbox_screw(type), thickness_below = thickness, star_washers = star_washers, short_insert = short);
                     else
                         fastened_fixing_block_assembly(is_missing_screw(q) ? 0 : t, bbox_screw(type), thickness2 = thickness, star_washers = star_washers);
 

readme.md

@@ -4617,10 +4617,10 @@ The top bezel can have an optional child, which is subtracted to allow modificat
 | `box_left_blank(type, sheet = false)` | Generates a 2D template for the left sheet, `sheet` can be set to override the type |
 | `box_right(type)` | Default right side, can be overridden to customise |
 | `box_right_blank(type, sheet = false)` | Generates a 2D template for the right sheet, `sheet` can be set to override the type |
-| `box_shelf_blank(type, sheet = false)` | Generates a 2D template for a shelf sheet |
+| `box_shelf_blank(type, sheet = false, wall = undef)` | Generates a 2D template for a shelf sheet |
 | `box_shelf_bracket(type, screw_positions, wall = undef)` | Generates a shelf bracket, the first optional child is a 2D cutout and the second 3D cutouts |
 | `box_shelf_bracket_section(type, rows, cols, x, y)` | Generates sections of the shelf bracket to allow it to be bigger than the printer |
-| `box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = undef)` | Place children at the shelf screw positions |
+| `box_shelf_screw_positions(type, screw_positions, thickness = 0, wall = undef, top_screws = true)` | Place children at the shelf screw positions |
 | `box_top(type)` | Default top, can be overridden to customise |
 | `box_top_blank(type)` | Generates a 2D template for the top sheet |
 | `grill(width, height, r = 1000, poly = false, h = 0)` | A staggered array of 5mm holes to make grills in sheets. Can be constrained to be circular. Set `poly` `true` for printing, `false` for milling. |
@@ -4697,6 +4697,7 @@ fixing_blocks along the sides.
 | `bbox_name(type)` | Optional name if there is more than one box in a project |
 | `bbox_screw(type)` | Screw type for corner blocks |
 | `bbox_sheets(type)` | Sheet type for the sides |
+| `bbox_short_inserts(type)` | Set to use short inserts in the blocks |
 | `bbox_skip_blocks(type)` | List of fixing blocks to skip, used to allow a hinged panel for example |
 | `bbox_span(type)` | Maximum span between fixing blocks |
 | `bbox_star_washers(type)` | Set to false to remove star washers. |
@@ -4707,7 +4708,7 @@ fixing_blocks along the sides.
 ### Functions
 | Function | Description |
 |:--- |:--- |
-| `bbox(screw, sheets, base_sheet, top_sheet, span, size, name = "bbox", skip_blocks = [], star_washers = true, thin_blocks = false)` | Construct the property list for a butt_box |
+| `bbox(screw, sheets, base_sheet, top_sheet, span, size, name = "bbox", skip_blocks = [], star_washers = true, thin_blocks = false, short_inserts = false)` | Construct the property list for a butt_box |
 | `bbox_area(type)` | Internal surface area in m^2 |
 | `bbox_volume(type)` | Internal volume in litres |