Ross, The traditional way of drafting roving was with a diz. This is a little disc, usually of wood, with a small hole at the center. When wool is removed from the combs (not cards, in this case), you start a few strands through the hole in the diz and begin to pull it through, winding it off into a ball as you go. You can still buy a diz, need to have the patience to sit and draw everything through!
Kathleen