Be aware there's no automatic, semiautomatic, or fast way to do what you want -- but it can be done.
The various available Trace tools I've tried are not accurate or reliable enough for your application. Best approach is to import the .jpg or .bmp image (using Insert|Picture|From file) and then trace it manually, using Polylines and/or Splines as appropriate. You'll then have to apply one or more of TCad's various 3D tools to make TCad 3D models which a CAM program will recognize. (Simple example: Trace a circle, then extrude it, and the result is a TCad Cylinder.)