using transparent PETG, print the model on a smooth plate ( I used $12 sheet from Juuprine - PEY Circle, 100℃. For other plates, change the bed temperatures)
after opening the idler, remove the old front case:
remove the washer from the old case:
insert the washer into the new case:
clear the holes (if necessary):
put a drop of machine oil in the center the clear the view