What did you use before the ROS? Elbow grease? Sad but true, often a referral to old tried and true procedures. I got to thinking, last time I used my ROS the disc flew off on its own???? I was done so I didn't investigate, but I have plans for mine this week and so I wandered into the shop to check mine, I put a new disc on the ROS and it held and worked fine on a pass or two on an old piece of ply. I'm safe. I have a couple of ROSs but there is always my "favorite" and that was what I am taking with me on the off campus job.
Merry Christmas