challange to make motion study for roller window

Dear all>

i have a challege to create a motion study for roller window ( see attached pic ) to determine the motor capasity and velosities >

i need your advice  how to represent the  fabric curtain ????

i tried many ways but till now all of them failed and the best of them was to separate the curtain to small slices and mate them togther in to points but it was very prossessing

consuming and always the solution don't complete

waiting your advice and thank you in advance ?

SolidworksMotion Studies