commit 672995835a9ce196f5caa13e0291cdf120d0b9c2
Author: Correl Roush <correl@gmail.com>
Date:   Tue Dec 6 10:58:59 2022 -0500

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..098dc5b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+*~
+*.stl
diff --git a/fit_test.scad b/fit_test.scad
new file mode 100644
index 0000000..7557987
--- /dev/null
+++ b/fit_test.scad
@@ -0,0 +1,6 @@
+use <project_box.scad>
+$fn=50;
+
+project_box(50, 70,
+            above=0,
+            below=1);
diff --git a/project_box.scad b/project_box.scad
new file mode 100644
index 0000000..d6082e2
--- /dev/null
+++ b/project_box.scad
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+/* Project box
+
+A parametric box for perforated circuit boards. The board is held above the
+bottom of the box by four corner supports, and snaps into place to hold it
+snugly while allowing easy removal.
+*/
+
+$fn=50;
+
+board_x = 50;
+board_y = 70;
+board_thickness = 1; // [1:10]
+clearance_above = 20; // [5:50]
+clearance_below = 10; // [5:50]
+fit_tolerance = 0.5;
+corner_radius=3; // [1:10]
+support_radius=5; // [1:10]
+wall_width=3; // [3:10]
+
+module _rounded_box(h, w, d, r) {
+  hull() {
+    translate([0 + r,0 + r,0])
+      cylinder(h=h,r=r);
+    translate([w - r,0 + r,0])
+      cylinder(h=h, r=r);
+    translate([w - r,d - r,0])
+      cylinder(h=h, r=r);
+    translate([0 + r,d - r,0])
+      cylinder(h=h, r=r);
+  }
+
+}
+
+module corner_post(h, r) {
+  intersection() {
+    translate([-0.001,-0.001,-0.001])
+      cube([r*1.1, r*1.1, h*1.2]);
+    cylinder(h=h, r=r);
+  }
+}
+
+module project_box(x, y,
+                   above=20,
+                   below=10,
+                   board_thickness=1,
+                   fit_tolerance=0.5,
+                   corner_radius=3,
+                   support_radius=5,
+                   wall_width=3) {
+  height=board_thickness + above + below + (fit_tolerance * 2);
+  width=board_x + (fit_tolerance * 2);
+  depth=board_y + (fit_tolerance * 2);
+
+  // container
+  difference() {
+    _rounded_box(h=height + (wall_width * 2),
+                 w=width + (wall_width * 2),
+                 d=depth + (wall_width * 2),
+                 r=corner_radius);
+    translate([wall_width,wall_width,wall_width])
+      cube([width, depth, height + (wall_width * 2)]);
+  }
+
+  // supports
+  translate([wall_width,wall_width,wall_width]) {
+    translate([0,0,0])
+      corner_post(h=below, r=support_radius);
+    translate([width,0,0])
+      rotate([0,0,90])
+      corner_post(h=below, r=support_radius);
+    translate([0,depth,0])
+      rotate([0,0,270])
+      corner_post(h=below, r=support_radius);
+    translate([width,depth,0])
+      rotate([0,0,180])
+      corner_post(h=below, r=support_radius);
+  }
+
+
+  // locking nubs
+  translate([wall_width,wall_width,wall_width]) {
+    nub_size = 1;
+    nub_width = board_y / 4;
+    nub_height = below + board_thickness + (nub_size/2) + (fit_tolerance*2);
+    translate([0,board_y / 2 - nub_width / 2,nub_height])
+      rotate([270,0,0])
+      cylinder(h=nub_width, r=1);
+    translate([width,board_y / 2 - nub_width / 2,nub_height])
+      rotate([270,0,0])
+      cylinder(h=nub_width, r=1);
+  }
+}
+
+project_box(board_x, board_y,
+            above=clearance_above,
+            below=clearance_below,
+            board_thickness=board_thickness,
+            fit_tolerance=fit_tolerance,
+            corner_radius=corner_radius,
+            support_radius=support_radius,
+            wall_width=wall_width);