Add tank track covers

tank-track-cover.scad

@@ -0,0 +1,89 @@
+WIDTH = 30; /* track width */
+CURVE_RADIUS = 25; /* track wheel cover curve radius */
+AXLE_DISTANCE = 195; /* how far is the front motor from back motor */
+THICKNESS=1.5; /* plastic thickness all around */
+CLEARANCE = 10; /* clearance around axles and suspension mounts */
+
+
+module mount_pad(left, top, diameter=4) {
+    translate([left, top]) {
+       difference() {
+           union() {
+             cylinder(h=THICKNESS, r1=diameter*1.5, r2=diameter*1.5, $fn=50);
+             translate([-diameter*1.5, 0, 0]) {
+               cube([diameter*3, diameter*3, THICKNESS]);
+             }
+           }
+           cylinder(h=THICKNESS, r1=diameter/2, r2=diameter/2, $fn=50);
+       }
+    }
+}
+
+/* bucket creates cylinder with inner cylinder removed */
+module bucket() {
+  difference() {
+    cylinder(h = WIDTH, r1 = CURVE_RADIUS+THICKNESS, r2 = CURVE_RADIUS+THICKNESS, $fn=100);
+    translate([0, 0, THICKNESS]) {
+        cylinder(h = WIDTH, r1 = CURVE_RADIUS, r2 = CURVE_RADIUS, $fn=100);
+    }
+    cylinder(h=THICKNESS, r1=CLEARANCE, r2=CLEARANCE, $fn=50);
+    rotate(135) {
+      cube([CURVE_RADIUS+THICKNESS, CURVE_RADIUS+THICKNESS, WIDTH]);
+    }
+  }
+}
+
+module track_cover() {
+  difference() {
+    union() {
+      /* mounting edge */
+      translate([0, CLEARANCE, 0]) {
+        cube([AXLE_DISTANCE, CURVE_RADIUS-CLEARANCE, THICKNESS]);
+      }
+      
+      /* wheel covers */
+      bucket();
+      translate([AXLE_DISTANCE, 0, 0]) {
+       mirror([1, 0, 0]) {
+         bucket();
+       }
+      }
+      
+      /* cover on the top */
+      translate([0, CURVE_RADIUS]) {
+        cube([AXLE_DISTANCE, THICKNESS, WIDTH]);
+      }
+    }
+    union() {      
+      /* cutout lower half */
+      translate([-CURVE_RADIUS-THICKNESS, -CURVE_RADIUS-THICKNESS]) {
+        cube([10000, CURVE_RADIUS+THICKNESS, 10000]);
+      }
+      
+      /* cutout inner arcs */
+      translate([0, 0, THICKNESS]) {
+        cube([AXLE_DISTANCE, CURVE_RADIUS, WIDTH]);
+      }
+      
+      /* cutout clearance */
+      cube([AXLE_DISTANCE, CLEARANCE, THICKNESS]);
+    }
+  }
+  mount_pad(28, 5);
+  mount_pad(63, 5);
+  mount_pad(63+39, 5);
+  mount_pad(63+39*2, 5);
+
+}
+
+module track_cover_set() {
+  track_cover();
+  mirror([0,1,0]) {
+    translate([0, -CURVE_RADIUS*2-THICKNESS*3, 0]) {
+      track_cover();
+    }
+  }
+}
+
+track_cover_set();
+