Merge b0b483a172 into fd4db5aa9f

gridfinity-rebuilt-utility.scad

@@ -5,6 +5,7 @@
  */
 
 include <standard.scad>
+include <gridfinity-stacking-lip-constants.scad>
 
 // ===== User Modules ===== //
 
@@ -125,7 +126,6 @@ module gridfinityInit(gx, gy, h, h0 = 0, l = l_grid, sl = 0) {
     $dh = h;
     $dh0 = h0;
     $style_lip = sl;
-    color("tomato") {
     difference() {
         color("firebrick")
         block_bottom(h0==0?$dh-0.1:h0, gx, gy, l);
@@ -133,9 +133,8 @@ module gridfinityInit(gx, gy, h, h0 = 0, l = l_grid, sl = 0) {
     }
     color("royalblue")
     block_wall(gx, gy, l) {
-        if ($style_lip == 0) profile_wall();
-        else profile_wall2();
-    }
+        if ($style_lip == 0) profile_wall(h);
+        else profile_wall2(h);
     }
 }
 // Function to include in the custom() module to individually slice bins
@@ -362,51 +361,78 @@ module refined_hole() {
     }
 }
 
-module profile_wall_sub_sub() {
-    polygon([
-        [0,0],
-        [d_wall/2,0],
-        [d_wall/2,$dh-1.2-d_wall2+d_wall/2],
-        [d_wall2-d_clear,$dh-1.2],
-        [d_wall2-d_clear,$dh+h_base],
-        [0,$dh+h_base]
-    ]);
-}
+/**
+ * @brief Stacking lip with a chamfered top.
+ * @details Based on https://gridfinity.xyz/specification/
+ *          Also includes a support base.
+ */
+module stacking_lip_chamfered() {
+    // Replace 2D edge with a radius.
+    // Method used: tangent, tangent, radius algorithm
+    // See:  https://math.stackexchange.com/questions/797828/calculate-center-of-circle-tangent-to-two-lines-in-space
+    before_chamfer = stacking_lip_points[2];
+    to_chamfer = stacking_lip_points[3]; // tip, Point to Chamfer
+    after_chamfer = stacking_lip_points[4];
 
-module profile_wall_sub() {
-    difference() {
-        profile_wall_sub_sub();
-        color("red")
-        offset(delta = d_clear)
-        translate([r_base-d_clear,$dh,0])
-        mirror([1,0,0])
-        profile_base();
+    chamfer_vectors = [
+        to_chamfer - before_chamfer,
+        after_chamfer - to_chamfer,
+        ];
+
+    to_chamfer_angle = 180 +
+        atan2(
+            cross(chamfer_vectors[0], chamfer_vectors[1]),
+            chamfer_vectors[0] * chamfer_vectors[1]
+        );
+    half_angle = to_chamfer_angle / 2;
+
+    // Distance from tip to the center point of the circle.
+    distance_from_edge = r_f1 / sin(half_angle);
+
+    // Circle's center point
+    chamfer_center_vector = [
+        distance_from_edge * sin(half_angle),
+        distance_from_edge * cos(half_angle)
+    ];
+    chamfer_center_point = to_chamfer - chamfer_center_vector;
+
+    // Exact point edges intersect the circle
+    intersection_distance = distance_from_edge * cos(half_angle);
+
+    union() {
+        // Rounded top chamfer
+        translate(concat(chamfer_center_point, [0]))
+        circle(r = r_f1);
+
+        // Stacking lip with cutout for circle to fit in
+        difference(){
+            polygon(stacking_lip_points);
+            translate([to_chamfer.x, to_chamfer.y, 0])
+            circle(r = intersection_distance);
+        }
     }
 }
 
-module profile_wall() {
-    translate([r_base,0,0])
-    mirror([1,0,0])
-    difference() {
-        profile_wall_sub();
-        difference() {
-            translate([0, $dh+h_base-d_clear*sqrt(2), 0])
-            circle(r_base/2);
-            offset(r = r_f1)
-            offset(delta = -r_f1)
-            profile_wall_sub();
-        }
-        // remove any negtive geometry in edge cases
-        mirror([0,1,0])
-        square(100*l_grid);
+/**
+ * @brief External wall profile, with a stacking lip.
+ * @details The "1.4" constant is to match old behavior.
+ */
+module profile_wall(height_mm) {
+    assert(is_num(height_mm))
+    translate([1.4, 0, 0]){
+        translate([0, height_mm, 0])
+        stacking_lip_chamfered();
+        translate([stacking_lip_depth-d_wall/2, 0, 0])
+        square([d_wall/2, height_mm]);
     }
 }
 
 // lipless profile
-module profile_wall2() {
+module profile_wall2(height_mm) {
+    assert(is_num(height_mm))
     translate([r_base,0,0])
     mirror([1,0,0])
-    square([d_wall,$dh]);
+    square([d_wall, height_mm]);
 }
 
 module block_wall(gx, gy, l) {

gridfinity-stacking-lip-constants.scad

@@ -0,0 +1,47 @@
+/**
+ * @file gridfinity-stacking-lip-constants.scad
+ * @brief Constants which define the stacking lip.
+ * @copyright MIT License, Arthur Moore 2024.
+ *            See LICENSE for more information.
+ */
+
+ include <standard.scad>
+
+//Based on https://gridfinity.xyz/specification/
+stacking_lip_inner_slope_height_mm = 0.7;
+stacking_lip_wall_height_mm = 1.8;
+stacking_lip_outer_slope_height_mm = 1.9;
+
+stacking_lip_depth =
+    stacking_lip_inner_slope_height_mm +
+    stacking_lip_outer_slope_height_mm;
+stacking_lip_height =
+    stacking_lip_inner_slope_height_mm +
+    stacking_lip_wall_height_mm +
+    stacking_lip_outer_slope_height_mm;
+
+// Extracted from `profile_wall_sub_sub`.
+stacking_lip_support_wall_height_mm = 1.2;
+stacking_lip_support_height_mm =
+    stacking_lip_support_wall_height_mm + d_wall2;
+
+
+
+// Technique: Descriptive constant names are useful, but can be unweildy.
+// Use abbreviations if they are going to be re-used repeatedly in a small piece of code.
+// Python style _ to indicate this is an internal variable.
+_slishmm = stacking_lip_inner_slope_height_mm;
+
+/**
+ * @brief Points used to make a stacking lip polygon.
+ * @details Also includes a support base.
+ */
+stacking_lip_points = [
+    [0, 0], // Inner tip
+    [_slishmm, _slishmm], // Go out 45 degrees
+    [_slishmm, _slishmm + stacking_lip_wall_height_mm], // Vertical increase
+    [stacking_lip_depth, stacking_lip_height], // Go out 45 degrees
+    [stacking_lip_depth, -stacking_lip_support_height_mm], // Down to support bottom
+    [0, -stacking_lip_support_wall_height_mm], // Up and in
+    [0, 0] // Close the shape. Tehcnically not needed.
+];

standard.scad

@@ -55,6 +55,7 @@ h_lip = 3.548;
 d_wall2 = r_base-r_c1-d_clear*sqrt(2);
 d_magic = -2*d_clear-2*d_wall+d_div;
 
+
 // Baseplate constants
 
 // Baseplate bottom part height (part added with weigthed=true)