+/* measured with calipers */
+ball_diameter = 12.7 + 0.825; // extra bit added for printing imprecision
+ball_radius = ball_diameter / 2;
+
+wall_thickness = 1;
+holder_height = (25 / 32) * ball_diameter + wall_thickness;
+
+holder_radius = ball_radius + wall_thickness;
+holder_diameter = holder_radius * 2;
+
+standoff_radius = holder_radius; // 0.580 / 2 inches from spec sheet