The fly frame takes the thicker draw sliver and drafts, twists, and winds it into a thinner roving package. It attenuates the sliver through multiple drafting rollers that increase in speed, which stretches and thins the material. A flyer inserts twist into the roving to hold the fibers together. The modern Toyoda FL-100 and FL-200 simplex machines have improved since the 1985 FL-16 model, with upgrades like changing from a cone drive system to independent servo motors for more accuracy and control of the drafting and winding process.