these three pieces will make it possible to turn any paper roll from either toilet paper, paper towels or others into a container with a screw cap.
these are made to fit a paper roll with an outside diameter of 43mm.

Print instructions

it can be printed with any printer, any nozzle size and any material.
the ones in the picture in printed in PETG and PLA with a 0.6mm nozzle on a PRUSA i3 MK3S.
no supports are needed as long as the pieces are oriented the right way, as they all have a flat side.
once the pieces are printed, the two ends is pressed into the paper roll, and then the screw cap can be attached and BOOM your done. good luck