# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1412626086 -7200
# Node ID 206e88f570e24389759a87832d77bbed515972e8
# Parent  315780887582c4347002cabd54cbbaef8fbac3d2
Changed the measurements to be based on an internal volume.

diff -r 315780887582 -r 206e88f570e2 cartridge.scad
--- a/cartridge.scad	Tue Jun 10 23:46:59 2014 +0200
+++ b/cartridge.scad	Mon Oct 06 22:08:06 2014 +0200
@@ -67,16 +67,12 @@
 			cube([width, depth, height], center = true);
 	}
 
-	/* Cartridge dimensions. */
+	/* Internal dimensions. */
 
-	width = 90.0;
-	height = 68.3;
-	depth = 16.5;
-	front_depth = 6.5;
-
-	/* How much extra depth the back provides for mating with the front. */
-	groove_width_extra = 2.0;
-	back_depth = depth - front_depth + groove_width_extra;
+	int_width = 86.0;
+	int_payload_height = 51.8;	/* includes bottom of payload area */
+	int_connector_height = 13.5; 	/* height of bottom/floor of payload area */
+	int_depth = 11.0;
 
 	/* Side thicknesses. */
 
@@ -85,6 +81,23 @@
 	top = 3;
 	side = 2; /* increased from 1.5 for 3D printing reliability */
 
+	/* How much extra depth the back provides for mating with the front. */
+
+	groove_width_extra = 2.0;
+
+	/* Division of pieces into front and back. */
+
+	front_depth = 6.5;
+
+	/* Cartridge dimensions. */
+
+	width = int_width + side + side;
+	height = int_payload_height + int_connector_height + top;
+	depth = int_depth + front + back;
+	back_depth = depth - front_depth + groove_width_extra;
+
+	/* Cartridge surfaces. */
+
 	front_side = side;
 	front_left = front_side;
 	front_right = front_side;
@@ -162,10 +175,6 @@
 	inner_front_edge_height = 3.0;
 	inner_front_edge_depth = 1.5;
 
-	/* The height of the floor of the compartment above the very bottom. */
-
-	bottom_from_base = 13.5;
-
 	edge_connector_cutout_front_offset = 1.0;
 	edge_connector_cutout_front_depth = 1.0;
 	edge_connector_cutout_front_width = 15.0;
@@ -183,7 +192,7 @@
 	pcb_back_support_width = 1.2;
 	pcb_back_support_depth = back_depth -
 		edge_connector_cutout_back_depth;
-	pcb_back_support_height = height - bottom_from_base - top - bottom;
+	pcb_back_support_height = height - int_connector_height - top - bottom;
 
 	pcb_front_support_width = 1.2;
 	pcb_front_support_depth = front_depth;
@@ -240,7 +249,7 @@
 		translate([xdir *
 			pcb_support_offset_from_centre,
 			edge_connector_cutout_back_depth,
-			-height / 2 + bottom + bottom_from_base])
+			-height / 2 + bottom + int_connector_height])
 			justify(pcb_back_support_width,
 				pcb_back_support_depth,
 				pcb_back_support_height,
@@ -280,7 +289,7 @@
 		translate([xdir *
 			(width/2 - pcb_lug_offset_from_outside),
 			back_depth,
-			-height / 2 + bottom + bottom_from_base +
+			-height / 2 + bottom + int_connector_height +
 				pcb_lug_offset_from_bottom
 			])
 			rotate([90, 0, 0])
@@ -304,7 +313,7 @@
 		translate([xdir *
 			(width/2 - pcb_lug_offset_from_outside),
 			-front_depth + front + pcb_front_lug_depth,
-			-height / 2 + bottom + bottom_from_base +
+			-height / 2 + bottom + int_connector_height +
 				pcb_lug_offset_from_bottom
 			])
 			rotate([90, 0, 0])
@@ -341,7 +350,7 @@
 
 				cube_at(width, front_depth, bottom,
 					0, -1, 1,
-					0, 0, -height / 2 + bottom_from_base);
+					0, 0, -height / 2 + int_connector_height);
 
 				/* Left cutout. */
 
@@ -351,7 +360,7 @@
 					1, -1, 1,
 					-width / 2 + edge_connector_cutout_front_offset,
 					0,
-					-height / 2 + bottom_from_base);
+					-height / 2 + int_connector_height);
 
 				/* Right cutout. */
 
@@ -361,7 +370,7 @@
 					-1, -1, 1,
 					width / 2 - edge_connector_cutout_front_offset,
 					0,
-					-height / 2 + bottom_from_base);
+					-height / 2 + int_connector_height);
 			}
 
 			/* PCB supports. */
@@ -373,7 +382,7 @@
 					-edge_connector_cutout_back_width / 2 +
 						pcb_support_margin,
 					0,
-					-height / 2 + bottom + bottom_from_base);
+					-height / 2 + bottom + int_connector_height);
 
 			cube_at(pcb_front_support_width,
 					pcb_front_support_depth,
@@ -382,7 +391,7 @@
 					edge_connector_cutout_back_width / 2 -
 						pcb_support_margin,
 					0,
-					-height / 2 + bottom + bottom_from_base);
+					-height / 2 + bottom + int_connector_height);
 
 			/* Circular "lugs" to hold PCBs in place. */
 
@@ -504,7 +513,7 @@
 
 				cube_at(width, back_depth, bottom,
 					0, 1, 1,
-					0, 0, -height / 2 + bottom_from_base);
+					0, 0, -height / 2 + int_connector_height);
 
 				/* Edge connector cutout. */
 
@@ -512,7 +521,7 @@
 					edge_connector_cutout_back_depth,
 					bottom,
 					0, 1, 1,
-					0, 0, -height / 2 + bottom_from_base);
+					0, 0, -height / 2 + int_connector_height);
 			}
 
 			/* PCB supports. */
@@ -606,7 +615,7 @@
 		/* Inner back cavities. */
 
 		translate([0, back_depth - inner_back_cavity_offset, -height / 2])
-			linear_extrude(height = bottom_from_base)
+			linear_extrude(height = int_connector_height)
 				translate([-width / 2, 0, 0])
 					polygon([
 						[inner_back_cavity_offset_from_left, 0],
@@ -619,7 +628,7 @@
 						]);
 
 		translate([0, back_depth - inner_back_cavity_offset, -height / 2])
-			linear_extrude(height = bottom_from_base)
+			linear_extrude(height = int_connector_height)
 				translate([-width / 2, 0, 0])
 					polygon([
 						[width - inner_back_slope_offset_from_left, 0],
@@ -675,4 +684,4 @@
 	}
 }
 
-cartridge();
\ No newline at end of file
+cartridge();