and 62 rotate in opposite directions as indicated by the arrows 64 and 65 the calendaring rollers 60 and 62 each mount on respective drive shafts 66 the drive shafts 66 of each roller operatively connects to the same variable speed drive motor not illustrated this assures that the calendaring rollers 60 and 62 rotate at uniform speeds for guiding the flexible core 12 between the pair of rollers the calendaring rollers 60 and 62 each have a central v groove 68 defined by inwardly tapering faces 70 the rollers 60 and 62 are positioned adjacent each other so that the rollers just contact each other the v grooves in the pair of rollers defines a central opening 72 through which the flexible core 12 passes the illustrated embodiment uses three pairs of the calendaring rollers 60 and 62 the opening 72 decreases in cross sectional width in sequence from one set of the rollers 60 and 62 to the next set of rollers returning now to fig4 a tube member 76 extends between a lower side of the pair of rollers 60a and 62a and an upper side of the second pair of rollers 60b and 62b similarly a second tube 78 extends between the lower side of the second pair of rollers 60b and 62b and the upper side of the third pair of rollers 60c and 62c.