I always spoke privately to all of my professors beforehand, to give them a sense of the struggle it would be for me to speak in front of the class. I also enrolled with my university's Accessibility Services department, so that I could have formal accommodations on my file. I rarely actually had to use the accommodations, but I felt that I would always be graded more fairly if there was formal documentation of my disability. I did find that professors were more lenient with my timed presentations, so people actually liked being in my group! They ended up with more relaxed standards because of me ;) ​ I am not ashamed of my stutter, so I had no problem telling group members of my trouble, too. I see it as "well, it's no secret I stutter. They'll hear it. So why not own it and be upfront?" In my experience, classmates were always accommodating and understanding.