Circle command
      Draw a circle
  command
      Starting a command
  command:  start
      Starting a command
  control points
      Set weights for the control points
  control points:  set weights
      Set weights for the control points
  draw
      Draw a line
  draw:  line
      Draw a line
  ExtractIsoparm command
      Extract an isoparm curve from the loft
  Join command
      Rotate and join curve parts
  Line command
      Draw a line
  Loft command
      Loft the spiral
  Pipe command
      Model the spring thickness
  Rotate command
      Rotate and join curve parts
  Scale2D command
      Scale the spring path diameter
  set weights
      Set weights for the control points
  set weights:  control points
      Set weights for the control points
  Spiral command
      Draw a spiral
  Weight command
      Set weights for the control points