Specific diameter opening required
This section enables the user to generate a fibre path to give a component, which will have a specific diameter opening in one end. At an end of a component, the fibre turns round, and therefore, the fibre will be travelling in a hoop direction around the mandrel. We can therefore use this property to start the fibre at this position in the hoop direction.
The user can fix the X position by using the RADIUS option at menu 3.4. The user is prompted for the mandrel radius at the end opening, the software the start at the left and of the mandrel putting a marker on the mandrel when the mandrel radius matches the value entered. A menu with SELECT THIS POINT YES/NO? appears. If NO is selected the next location on the mandrel is shown. This option cannot be used to start on a cylindrical section at there are an infinite number of locations! If the user does not select any of the choices (or if no choices exist) the software returns to the previous menu.
Having specified the start location select HOOP U or HOOP D. The selection will fix the direction of mandrel rotation. For example, if the machine's positive direction of mandrel rotation was clockwise when viewed in a positive direction along the mandrel's axis of revolution, then the user would select HOOP U, in order that the instructions to the machine controller are not all negative. In some cases (when using the 5 axis 3 plane or the 6 axis post processors, the mandrel rotation direction can be important if the machine 'head' is not symmetric as these post processors use three Cartesian axes of motion (XYZ).
Having specified the fibre path start position the path can be generated as normal with or without the use of friction. If the path is generated fully geodesically, the end opening diameter will be the same at the other end of the mandrel (to within the accuracy of the numerical predictions). If a larger or smaller opening at the other end is required friction must be used. The path can be advanced and deleted over the mandrel end using different amounts of friction until the specific diameter is achieved. This can usually be done in 2 or 3 iterations and is made substantially easier if a mandrel end view is selected from the VIEWS menu.