My first object - a wheel with spokes

wheel.scad

@@ -0,0 +1,29 @@
+$fn=100;
+
+module wheel(radius, width, thickness, spokes) {
+	union() {
+		difference() {
+			// basis for our wheel - a sphere
+			sphere(radius);
+			// upper cut-out
+			translate([0,0,width/2])
+				cylinder(radius-(width/2) +1, radius, radius, 0);
+			// lower cut-out
+			translate([0,0,-radius -1])
+				cylinder(radius-(width/2) +1, radius, radius, 0);
+			/*
+				inner cut-out
+				removing 1 from z on translate and making the cylinder
+				higher by two to generate slightly more valid objects
+			*/
+			translate([0,0,-width/2 -1])
+				cylinder(width+2, radius-thickness, radius-thickness, 0);
+		}
+		// spokes
+		for (i = [0:(360/spokes):360]) {
+			rotate([0,0,i])
+				translate([-(radius-thickness),-(radius-thickness)/(spokes*2), -(width/2)])
+					cube([(radius-thickness), (radius-thickness)/(spokes), width]);
+		}
+	}
+}