I have wanted to do this for a while but needed a chuck for my lathe, since I got one last week I figured I would go for it. I had to enlarge the hole in the body and take a bit off the tip to get the bearing to fit, its all pretty snug and I tapped the bearing in flush with a hammer. this is probably the wrong section but move it if needed. all done freehand on a wood lathe, there is a TINY wobble because the bearing didnt go in exactly straight but it still works wonderfully.
http://hphotos-snc3.fbcdn.net/hs652.snc3/32207_1200884962695_1845698020_388880_8072109_n.jpg