This invention concerns a winding device (10) for producing a roll of batting (12). For this purpose, the batting (14) is wound on a rotating core (H) driven by an endless belt (18). The core can be positioned in a loop (20) of the belt (18) formed between two pulleys (R1, R2) which can be stretched by means of a tension-setting device (22). As the size of the roll (12) increases, the size of the loop increases. At least one (R1) of the deviation pulleys (R1, R2) can be placed between a working position designed to form the loop (20) and an ejection position, into which the pulley can be positioned to eject the roll of batting (12), the belt (18) being stretched when the loop (20) is removed. In addition to the tension-setting device (22), at least one compensating element (R6, R6'', R2, R3, R5, R6') is provided to compensate for at least the greater part of the changes on belt length which arise in certain zones when the adjustable pulley (R1) is moved from a working position to an ejecting position and the belt (18) tightens during removal of the loop (20). On the other hand, the changes in belt length which arise during winding in certain zones as the loop (20) grows larger with increasing size if the batting roll (12) are compensated for the most part by the tension-setting device (22).