Started work on actual z-carriages

lib/rail_mount.scad

 cutout_width = 0.5;
 
 rail_mount_height = rail_y_off_1 + 6;
+rail_y_off = rail_dia / 2 + rail_y_off_1;
 
 draw_rail_mount = false;
     

xyRepRap.scad

 show_z_motion = true;
 
 show_heatbed_frame = true;
-show_heatbed = false;
+show_heatbed = true;
 
 show_xy_motion = true;
 show_x_carriage = false;
     
     // rail
     color("cyan")
-    translate([0, 15, 4])
+    translate([0, rail_y_off, 4])
         rail(outer_height - slot - 8);
 }
 
+z_carriage_wall = 10;
+
+module z_carriage() {
+    color("green")
+    translate([frame_off_x + bed_x_off - z_rail_x_off, frame_off_y + bed_y_off - rail_y_off, 0]) {
+        // bracket on long rail
+        translate([-z_carriage_wall, -z_carriage_wall, 0])
+            cube([z_carriage_wall, z_carriage_wall + (2 * slot), slot]);
+        
+        // bracket on short rail
+        translate([0, -z_carriage_wall, 0])
+            cube([3 * slot, z_carriage_wall, slot]);
+    }
+    
+    // TODO proper long bearings
+    color("magenta")
+    translate([0, 0, (slot - (2 * lm8uu_height + 1)) / 2]) {
+        %lm8uu();
+        %translate([0, 0, lm8uu_height + 1])
+            lm8uu();
+    }
+}
+
 module motion_z() {
     // front left
     translate([slot + z_rail_x_off, slot, 0])
         rotate([0, 0, 180])
         motion_z_rail();
     
+    // front left
+    translate([slot + z_rail_x_off, slot + rail_y_off, bed_draw_height - bed_z_dist - slot])
+        z_carriage();
+    // front right
+    translate([outer_width - slot - z_rail_x_off, slot + rail_y_off, bed_draw_height - bed_z_dist - slot])
+        scale([-1, 1, 1])
+        z_carriage();
+    // back left
+    translate([slot + z_rail_x_off, outer_length - slot - rail_y_off, bed_draw_height - bed_z_dist - slot])
+        scale([1, -1, 1])
+        z_carriage();
+    // back right
+    translate([outer_width - slot - z_rail_x_off, outer_length - slot - rail_y_off, bed_draw_height - bed_z_dist - slot])
+        scale([-1, -1, 1])
+        z_carriage();
+    
+    // yellow z-motor on top
     translate([(outer_width - nema17_size) / 2, outer_length - slot - nema17_size - nema17_mount_wall, outer_height + nema17_mount_wall])
     rotate([180, 0, 90]) {
         color("yellow")