I need a CAD design

Hello, Listed below are the dimensions of the object. The prototype is basically a hollow tube, (like a straw) bent in a spiral shape. When the object is in use, air will be flowing forward through the front of the tube. The attachments below are pictures of the sketch and general design of the object. Total length of the tube about: 8 ½ inch Inner diameter of the tube: 3/16th inch Outer diameter of the tube: 5/16th inch Outer diameter of the lip: 7/16th inch Length of the lip: 1/8th inch Start of tube at the lip to the first curve: 3/4th inch Last curve to the end of the tube: 3/4th inch Inner diameter of the tube end after the final curve (larger at the end): 5/16th inch Inner diameter of the separate end cap that fits onto the end of the tube: 15/32 inch Outer diameter of the separate end cap that fits onto the end of the tube: 11/16 inch The end cap should have grooves on the outside so that it can be turned more easily (similar to a tire stem cap). The end of the tube is stopped at the center by half of the diameter (a semicircle of material). The stop is located on the bottom side of the tube at the very end and is only 1/16th inch thick (see images). A cap will fit over this end, which also has a half stop, and will be attached via a tongue and groove type connection. The cap will be free to turn at any angle around the end of the tube to allow air to flow through the tube and out the upper half without any resistance or to completely stop the airflow. The end of the tube with its lower half stop, and the top of the cap with its half stop, should fit tightly together with no air gap between the half stops. The images provided show gaps between the tube as it spirals from the lip to the end. There should be no gaps in the spiral but should touch or share tube wall material.