I stopped ripping with the radial arm some time ago. To good a chance of kickback. Dang radial arm is just not solid enough and it causes kickbacks. At least my old timer does. I use my Grizzley table saw. Worse kickback I ever had was with a jointer. Man that thing can really throw things when you do stupid stuff. Sorry about your thumb, Yes it could have been worse, but that is some sore meat man. Thanks for reminding all of us old experienced saw users... we all tend to get "comfortable" and unafraid, and that is when it happens. I have lots of different kinds of saws, Just about everything anyone would have, and so far I still have all ten, and both eyes. But I know they can get you. My dad sawed the tip ends off of both thumbs thru the years. I know what that looks like.