Cadfil Help Contents Page

Cadfil - Advanced filament Winding software for program generation for all type of filament winding machine.

Filter length and filter angle

To generate an accurate geodesic path the mandrel must have a relatively large number of patches or elements. Fibre positions are calculated each time the path crosses the boundary of an element. The number of data points on the fibre path is much greater than the number of points required to accurately control the machine. Filter length and angle are used to remove (filter out) surplus data points. Subsequent data points on the fibre path are selected such that the distance between the points on the mandrel surface is not less than the filter length and the angle between the path direction vectors for successive data points is not greater than the filter angle. The default values are suitable for most purposes. The filter values cannot be zero and the filter angle is not permitted to be greater than 900. The internal default is 12 degrees but this can be changed using the SM file variable for example '$SM-FILTER-ANGLE=20.0 sets a default of 20 degrees.

Using very small filter values can lead to many very small motions on the winding machine. In many cases this leads to 'rough' operation of the machine and can lead to an increase in winding time.