I've seen one that uses a 1/8 or 3/16 thick strip of wood that clamped to the fence so that it bows down onto the work but I don't have a picture and it was quite while ago. Member with user name Botelho from Brazil , who we haven't seen here for a while, posted a very simple method for making a standard type one once. You could probably find it using the Community Search.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.