# Multi-Hoop Winding

Multiple Hoop winding generates a filament winding program that hoop winds between a series of specified positions on a cylindrical mandrel with an optional dwell (mandrel rotation only) at each of these points. The QuickCad Multi-Hoop winding options generates hoop winding programs and .Pay files that can be used for visualisation based on user specified parameters.

These user-specified parameters are:

This is the radius of the cylindrical mandrel.

This is the distance of the fibre dispensing point from the axis of the cylinder. This MUST be bigger than the mandrel radius.

Fibre Band Width

The width of the fibre band used to determine the winding angle such that the cylinder is fully covered by one circuit i.e. the carriage advances one band-with for each full mandrel rotation.

Angular Point Spacing (Deg)

This value determines the point spacing around the mandrel for generating the payout path. If the user wished to view the hoop winding band structure in the payout path viewing options then use a small value say 12 degrees, for creating NC data for winding a large value say 175 degrees is best. This value must be less than 180 degrees.

Mandrel Direction +1,-1

Set this to 1 for positive mandrel rotation and –1 for negative mandrel rotation.

Number Of X Positions

This is the number of X positions and is a whole number between 2 and 8. For example is three is specified the user is expected to specify X position 1 (X1) and dwell angle 1 (DW1) as well as X2,DW2 and x3,DW3 so in this example the machine would move to the first mandrel position and the mandrel will rotate DW1 degrees, the machine will then hoop wind (on a helical lead equal to the bandwidth) to the second position X2 and will then dwell for DW2 degrees, finally the machine will then hoop wind to position X3 and dwell for DW3 degrees.

If in this example X3=X1 we would have the sample program as the normal hoop winding program with a winding length of X2-X1

The number of positions is currently 20. If more than 20 are required used more than one multi-hoop programs to do this.

WARNING

If the values of the number of positions MUST match the number specified, if the user specified X1,X2,X3 & X4 but only set the number of points to 3 then X4 and dwell 4 would be ignored (and not saved). If only X1,X2 & X3 were set but the points were set to 4 then X4 would be assumed to be zero and the program would hoop wind to mandrel position X=0

X Position 1…

See above

Dwell (Deg) 1…

See Above

It may be a requirement that the user wishes to create a multi-hoop program where the X positions change in a formulaic way, an example of this is a hoop rib on a pipe where each layer steps in position from the last so that rib does not have a sharp edge that the bands would fall off after a few layers of height is added. In this way we might have a hoop with a series of positions in the series:

For a full example of this, see the Hoop winding using spreadsheet formulae page of the Cadfil website.

Updated: September 2020