The width of the roller blind is affected by the roller tube, so we choose different roller blinds for different lengths. Theoretically, the wider the roller blind width, the larger the diameter of the roller tube.
We have 38MM tube, 47MM tube, 50MM tube 63MM tube, 85MM tube and 90MM tube (diameter), 38 tube no more than 2 meters, 47 tube and 50 tube no more than 2.5, 53 tube no more than 3 meters, 90 tube no more than 6 Meters (the width of the roller blind), after which the coil will be at risk of deformation.
The choice of roller diameter depends on the width of the roller blind and the roller diameter of the motor. How to choose the motor we will mention in the next article
if the width is over the the tube capacity we can use tube joint , 
if we want save the money and let the roller blinds work in the same time ,then we need the solution on the below

180° Tube joint

90° Tube Joint


U-shape Tube Joint


Maxing Width Of Tube