# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1412635172 -7200
# Node ID cf96720ec877ff66ced2e2cc999b93e13cb1c95d
# Parent  88a49e3cbeb9d9fd9543a228d982afae34e82fe9
Changed the cavity features around the base of the cartridge to use internal dimensions.

diff -r 88a49e3cbeb9 -r cf96720ec877 cartridge.scad
--- a/cartridge.scad	Mon Oct 06 23:08:59 2014 +0200
+++ b/cartridge.scad	Tue Oct 07 00:39:32 2014 +0200
@@ -148,33 +148,38 @@
 
 	/*
 	The back cavity is the indented part at the bottom of the back of the
-	cartridge.
+	cartridge. It appears to be mechanically superfluous, just making the
+	shape of the cartridge look a bit fancier.
 	*/
 
 	back_cavity_width = 68.0;
 	back_cavity_inner_width = 65.0;
-	back_cavity_offset_from_left = 10.5;
-	back_cavity_inner_offset_from_left = 12.0;
+	back_cavity_offset_from_inner_left = 9.0;
+	back_cavity_inner_offset_from_inner_left = 10.5;
 	back_cavity_height = 13.5;
 	back_cavity_inner_height = 12.0;
 	back_cavity_depth = 1.5;
 
 	/*
-	The effect of the cavity on the inside of the case.
+	The effect of the cavity on the inside of the case. The most important
+	measurement is the maximum offset since it defines the width of the
+	internal space that should accommodate the plastic guides of the Plus 1
+	socket.
 	*/
 
-	inner_back_cavity_offset = 1.0;
-	inner_back_cavity_offset_from_left = back_left;
-	inner_back_slope_offset_from_left = 10.0;
-	inner_back_slope_width = 2.5;
 	inner_back_slope_depth = 2.5;
+	inner_back_slope_width = inner_back_slope_depth;
+	inner_back_slope_max_offset = 10.5;
+	inner_back_slope_min_offset = inner_back_slope_max_offset - inner_back_slope_width;
 
-	inner_back_edge_offset = 2.0;
+	/* The tapering off of the inner back edge. */
+
 	inner_back_edge_width = 69.0;
 	inner_back_edge_height = 3.0;
 	inner_back_edge_depth = 1.5;
 
-	inner_front_edge_offset = 0.5;
+	/* The tapering off of the inner front edge. */
+
 	inner_front_edge_width = width - front_side * 2;
 	inner_front_edge_height = 3.0;
 	inner_front_edge_depth = 1.5;
@@ -436,15 +441,14 @@
 
 		/* Inner front edge cavity. */
 
-		translate([inner_front_edge_width / 2,
-			-front_depth + inner_front_edge_offset, -height / 2])
+		translate([inner_front_edge_width / 2, -int_front_depth, -height / 2])
 			rotate([0, -90, 0])
 				linear_extrude(height = inner_front_edge_width)
 					polygon([
+						[-extra, -inner_front_edge_depth],
+						[0, -inner_front_edge_depth],
+						[inner_front_edge_height, 0],
 						[-extra, 0],
-						[0, 0],
-						[inner_front_edge_height, inner_front_edge_depth],
-						[-extra, inner_front_edge_depth],
 						]);
 
 		/* Inner top cutout for the top and sides of the back portion. */
@@ -601,15 +605,15 @@
 
 			translate([0, back_depth, -height / 2])
 				linear_extrude(height = back_cavity_height)
-					translate([-width / 2, 0, 0])
+					translate([-int_width / 2, 0, 0])
 						polygon([
-							[back_cavity_offset_from_left, 0],
-							[back_cavity_inner_offset_from_left,
+							[back_cavity_offset_from_inner_left, 0],
+							[back_cavity_inner_offset_from_inner_left,
 								-back_cavity_depth],
-							[back_cavity_inner_offset_from_left +
+							[back_cavity_inner_offset_from_inner_left +
 								back_cavity_inner_width,
 								-back_cavity_depth],
-							[back_cavity_offset_from_left +
+							[back_cavity_offset_from_inner_left +
 								back_cavity_width, 0]
 							]);
 
@@ -629,36 +633,32 @@
 
 		/* Inner back cavities. */
 
-		translate([0, back_depth - inner_back_cavity_offset, -height / 2])
+		translate([0, int_back_depth, -height / 2])
 			linear_extrude(height = int_connector_height)
-				translate([-width / 2, 0, 0])
+				translate([-int_width / 2, 0, 0])
 					polygon([
-						[inner_back_cavity_offset_from_left, 0],
-						[inner_back_slope_offset_from_left, 0],
-						[inner_back_slope_offset_from_left +
-							inner_back_slope_width,
-							-inner_back_slope_depth],
-						[inner_back_cavity_offset_from_left,
-							-inner_back_slope_depth]
+						[0, 0],
+						[inner_back_slope_max_offset, 0],
+						[inner_back_slope_min_offset,
+							inner_back_slope_depth],
+						[0, inner_back_slope_depth]
 						]);
 
-		translate([0, back_depth - inner_back_cavity_offset, -height / 2])
+		translate([0, int_back_depth, -height / 2])
 			linear_extrude(height = int_connector_height)
-				translate([-width / 2, 0, 0])
+				translate([int_width / 2, 0, 0])
 					polygon([
-						[width - inner_back_slope_offset_from_left, 0],
-						[width - inner_back_cavity_offset_from_left, 0],
-						[width - inner_back_cavity_offset_from_left,
-							-inner_back_slope_depth],
-						[width - inner_back_slope_offset_from_left -
-							inner_back_slope_width,
-							-inner_back_slope_depth]
+						[0, 0],
+						[-inner_back_slope_max_offset, 0],
+						[-inner_back_slope_min_offset,
+							inner_back_slope_depth],
+						[0, inner_back_slope_depth]
 						]);
 
 		/* Inner back edge cavity. */
 
 		translate([inner_back_edge_width / 2,
-			back_depth - inner_back_edge_offset, -height / 2])
+			int_back_depth + inner_back_edge_depth, -height / 2])
 			rotate([0, -90, 0])
 				linear_extrude(height = inner_back_edge_width)
 					polygon([