Add proper belt mounts to x-carriage

lib/linear_bearing.scad

 lm8uu_inner = 8;
 lm8uu_height = 24;
 
-x_rail_dist = 50;
+x_rail_dist = 60;
 
 lm8uu_dia_add = 0.5;
 lm8uu_len_add = 1.0;
 x_rail_hole_off = 5;
 x_rail_block_len = (y_carriage_length - x_rail_cutout_y) / 2;
 
+x_carriage_width = 80;
+x_carriage_len_add = 10;
+x_carriage_wall = 10;
+x_carriage_bearing_off = 3;
+
+x_carriage_belt_off = 19;
+x_carriage_belt_block_width = 8;
+x_carriage_belt_block_length = 8;
+x_carriage_belt_block_height = 25;
+x_carriage_belt_block_height_b = x_carriage_belt_block_height - 7;
+x_carriage_block_hole_off = 4.5;
+x_carriage_block_length = 4;
+x_carriage_block_off = 2.5;
+x_carriage_block_add = 4.4;
+
+x_carriage_length = x_rail_dist + (2 * x_carriage_len_add);
+
+x_carriage_block_height = 2 * (x_carriage_block_hole_off + x_carriage_block_add);
+
 draw_x_carriage = false;
 draw_y_carriage = false;
 draw_y_carriage_idlers = true;
     }
 }
 
-x_carriage_width = 60;
-x_carriage_len_add = 10;
-x_carriage_wall = 10;
-x_carriage_bearing_off = 3;
+module belt_fix() {
+    difference() {
+        color("green")
+        cube([x_carriage_belt_block_width, x_carriage_block_length, x_carriage_block_height]);
+        
+        translate([x_carriage_belt_block_width / 2, -1, x_carriage_block_hole_off - 0.2])
+        rotate([-90, 0, 0]) {
+            cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+            cylinder(d = 6.1, h = 3.8, $fn = 6);
+        }
+            
+        translate([x_carriage_belt_block_width / 2, -1, x_carriage_block_hole_off + 8.8])
+        rotate([-90, 0, 0]) {
+            cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+            cylinder(d = 6.1, h = 3.8, $fn = 6);
+        }
+    }
+}
+
+module belt_mount(top, up) {
+    $fn = 15;
+    
+    difference() {
+        color("green")
+        if (top) {
+            cube([x_carriage_belt_block_width, x_carriage_belt_block_length, x_carriage_belt_block_height]);
+        } else {
+            cube([x_carriage_belt_block_width, x_carriage_belt_block_length, x_carriage_belt_block_height_b]);
+        }
+        
+        if (top) {
+            translate([-1, x_carriage_belt_block_length / 2, 16])
+                rotate([0, 90, 0])
+                cylinder(d = 2.6, h = x_carriage_belt_block_width + 2);
+            
+            translate([x_carriage_belt_block_width / 2, -1, 16 + x_carriage_block_hole_off])
+                rotate([-90, 0, 0])
+                cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+            translate([x_carriage_belt_block_width / 2, -1, 16 - x_carriage_block_hole_off])
+                rotate([-90, 0, 0])
+                cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+        } else {
+            translate([-1, x_carriage_belt_block_length / 2, 9])
+                rotate([0, 90, 0])
+                cylinder(d = 2.7, h = x_carriage_belt_block_width + 2);
+            translate([x_carriage_belt_block_width / 2, -1, 9 + x_carriage_block_hole_off])
+                rotate([-90, 0, 0])
+                cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+            translate([x_carriage_belt_block_width / 2, -1, 9 - x_carriage_block_hole_off])
+                rotate([-90, 0, 0])
+                cylinder(d = 3.2, h = x_carriage_belt_block_length + 2);
+        }
+    }
+    
+    if (up) {
+        if (top) {
+            translate([0, x_carriage_belt_block_length + x_carriage_block_off, x_carriage_belt_block_height - x_carriage_block_height])
+                belt_fix();
+        } else {
+            translate([0, x_carriage_belt_block_length + x_carriage_block_off, x_carriage_belt_block_height_b - x_carriage_block_height])
+                belt_fix();
+        }
+    } else {
+        if (top) {
+            translate([0, -x_carriage_block_length - x_carriage_block_off, x_carriage_belt_block_height - x_carriage_block_height])
+                belt_fix();
+        } else {
+            translate([0, -x_carriage_block_length - x_carriage_block_off, x_carriage_belt_block_height_b - x_carriage_block_height])
+                belt_fix();
+        }
+    }
+}
+
+module belt_mounts() {
+    translate([0, x_carriage_belt_off, 0])
+        belt_mount(false, true);
+    
+    translate([0, x_carriage_length - x_carriage_belt_off - x_carriage_belt_block_length, 0])
+        belt_mount(true, false);
+    
+    translate([x_carriage_width - x_carriage_belt_block_width, x_carriage_belt_off, 0])
+        belt_mount(true, true);
+    
+    translate([x_carriage_width - x_carriage_belt_block_width, x_carriage_length - x_carriage_belt_off - x_carriage_belt_block_length, 0])
+        belt_mount(false, false);
+}
 
 module x_carriage() {
     //color("green")
     difference() {
-        color("green")
-        cube([x_carriage_width, x_rail_dist + (2 * x_carriage_len_add), x_carriage_wall]);
+        union() {
+            color("green")
+            cube([x_carriage_width, x_rail_dist + (2 * x_carriage_len_add), x_carriage_wall]);
+            
+            translate([0, 0, x_carriage_wall])
+                belt_mounts();
+        }
+        
+        // big center cutout
+        translate([x_carriage_width / 2, x_carriage_length / 2, x_carriage_wall / 2])
+            cube([x_carriage_width - (2 * x_carriage_belt_block_width) - 5, x_rail_dist - 25, x_carriage_wall + 2], center=true);
         
         for (i = [0 : 1 : 1]) {
             translate([lm8uu_height + x_carriage_bearing_off + (i * (x_carriage_width - (2 * x_carriage_bearing_off) - lm8uu_height)), 0, ])

xyRepRap.scad

         color("blue")
         translate([nema17_size / 2, nema17_size / 2 + 6.5, nema17_mount_wall + 1])
         rotate([0, 0, 180])
-            gt2_belt(outer_length - (5 * slot) - y_carriage_pos);
+            gt2_belt(outer_length - (2 * slot) - nema17_size / 2 - x_rail_dist - y_carriage_pos - 15);
         color("blue")
         translate([-outer_length + (3 * slot) + 10 + nema17_size / 2, nema17_size / 2 - 6.5, nema17_mount_wall + 1])
             gt2_belt(outer_length - (3 * slot) - 10);
         rotate([0, 0, 180])
             gt2_belt(outer_length - (3 * slot) - 10);
         color("red")
-        translate([nema17_size / 2 - (outer_length - (5 * slot) - y_carriage_pos), nema17_size / 2 - 6.5, nema17_mount_wall + 8])
-            gt2_belt(outer_length - (5 * slot) - y_carriage_pos);
+        translate([nema17_size / 2 - (outer_length - (2 * slot) - nema17_size / 2 - x_rail_dist - y_carriage_pos - 15), nema17_size / 2 - 6.5, nema17_mount_wall + 8])
+            gt2_belt(outer_length - (2 * slot) - nema17_size / 2 - x_rail_dist - y_carriage_pos - 15);
     }
     
     // x carriage belts on blue side
     color("blue")
-    translate([slot + 29, slot + 32 + 25 + y_carriage_pos, outer_height - 1])
+    translate([slot + 29, slot + x_rail_dist + 7 + y_carriage_pos, outer_height - 1])
         rotate([180, 0, 0])
         gt2_belt(x_carriage_pos - 20);
     color("red")
     
     // x carriage belts on red side
     color("red")
-    translate([slot + 50 + x_carriage_pos, slot + 32 + 25 + y_carriage_pos, outer_height - 8])
+    translate([slot + x_carriage_width + x_carriage_pos - 7, slot + x_rail_dist + 7 + y_carriage_pos, outer_height - 8])
         rotate([180, 0, 0])
-        gt2_belt(outer_width - x_carriage_pos - (2 * slot) - 80);
+        gt2_belt(outer_width - x_carriage_pos - (2 * slot) - x_carriage_width - 20);
     color("blue")
-    translate([slot + 50 + x_carriage_pos, slot + 23 + y_carriage_pos, outer_height - 1])
+    translate([slot + x_carriage_width + x_carriage_pos - 7, slot + 23 + y_carriage_pos, outer_height - 1])
         rotate([180, 0, 0])
-        gt2_belt(outer_width - x_carriage_pos - (2 * slot) - 70);
+        gt2_belt(outer_width - x_carriage_pos - (2 * slot) - x_carriage_width - 10);
     
     // long back belts
     color("blue")