Battery cover rail

cad/display.scad

@@ -92,6 +92,14 @@ module battery_compartment(){
       translate([hole_x, depth+(thickness*2)-hole_y, height+battery_height])
         cylinder(h=thickness, d=hole);
     }
+
+    // rails
+    translate([19, thickness+0.1, height+battery_height+thickness])
+      female_rail(battery_width-19);
+
+    translate([19, depth+thickness-0.1, height+battery_height+thickness])
+      mirror([0, 1, 0])
+        female_rail(battery_width-19);
 }
 
 module rpi4_cover(){
@@ -176,4 +184,25 @@ module male_hinge(){
     tab(l, th);
   translate([0, sp, 0])
     tab(l, th);
+}
+
+module female_rail(length){
+  difference(){
+    cube([length, 2.4, 3]);
+
+    translate([0, -0.12, 0.09])
+      rotate([45, 0, 0])
+        cube([length, 2, 2]);
+  }
+}
+
+module male_rail(length){
+  difference(){
+    translate([0, -0.12, 0.09])
+      rotate([45, 0, 0])
+        cube([length, 2, 2]);
+
+    translate([0, -1, 0])
+      cube([length, 1, 3]);
+  }
 }