Ok shars bs1 indexer. I had to make a back plate for the chuck. So I did that from one that was already made that you need to machine to final size to fit the chuck. I face the back and front and added relief in the back where it mounts the the indexer. I have about .008 run out and I'm trying to figure out why. But what is even acceptable with these? I have no idea. I checked the back plate on a surface plate and maybe I have .001. So that's good. The indexer itself is maybe .00015 where I belive I should mount it. I'm at a loss of were this is all coming from. The threads? Maybe I have it wrong were it butts up in the shoulder? Any ideas?